From aab7cbbc279d17e2ce32f6f0201947bbceb4919f Mon Sep 17 00:00:00 2001
From: Glenn Watson <5834289+glennawatson@users.noreply.github.com>
Date: Mon, 21 Sep 2026 19:30:56 +1000
Subject: [PATCH 1/2] chore: Update NuSourceDocs to 1.13.0

---
 Directory.Packages.props | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Directory.Packages.props b/Directory.Packages.props
index d224ff4d..6be6ee66 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -2,7 +2,7 @@
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
     <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
-    <NuStreamDocsVersion>1.12.0</NuStreamDocsVersion>
+    <NuStreamDocsVersion>1.13.0</NuStreamDocsVersion>
   </PropertyGroup>
 
   <ItemGroup>

From 8fb97385f4762e2a3aad26385b2fcf0ad621e4e0 Mon Sep 17 00:00:00 2001
From: Glenn Watson <5834289+glennawatson@users.noreply.github.com>
Date: Mon, 21 Sep 2026 23:56:12 +1000
Subject: [PATCH 2/2] docs(binding): add the ReactiveUI.Binding documentation
 section

- Add a Binding section with index, observing, bindings, converters, custom converters, mechanisms, views, threading, setup and unsafe pages.
- End every page with an API reference table that lists each public member with its source link.
- Add a generated API reference page for every public type and member.
- Quote each code sample from the runnable example projects in the ReactiveUI.Binding repository.
- Replace the when-any, value-converters, windows-forms, binding-commands and binding-interactions handbook pages with redirects to the Binding pages.
- Rewrite the data-binding handbook index as a short hub that links into the Binding section.
- Point the links on 13 existing pages at the new Binding pages.
- List ReactiveUI.Binding in nuget-packages.json.
---
 docs/_redirects                               |   16 +
 docs/documentation/binding/api.md             | 3770 +++++++++++++++++
 docs/documentation/binding/bindings.md        | 1934 +++++++++
 docs/documentation/binding/converters.md      |  775 ++++
 .../binding/custom-converters.md              | 1034 +++++
 docs/documentation/binding/index.md           |  233 +
 docs/documentation/binding/mechanisms.md      | 1519 +++++++
 docs/documentation/binding/observing.md       | 1999 +++++++++
 docs/documentation/binding/setup.md           | 1236 ++++++
 docs/documentation/binding/threading.md       | 1551 +++++++
 docs/documentation/binding/unsafe.md          | 1473 +++++++
 docs/documentation/binding/views.md           | 1008 +++++
 .../getting-started/compelling-example.md     |    2 +-
 docs/documentation/getting-started/index.md   |    2 +-
 .../handbook/commands/binding-commands.md     |  163 -
 docs/documentation/handbook/commands/index.md |    4 +-
 .../handbook/data-binding/index.md            |  191 +-
 .../handbook/data-binding/value-converters.md |   94 -
 .../handbook/data-binding/windows-forms.md    |    6 -
 .../interactions/binding-interactions.md      |   59 -
 .../handbook/user-input-validation.md         |    2 +-
 .../handbook/view-models/index.md             |    8 +-
 docs/documentation/handbook/when-activated.md |    2 +-
 docs/documentation/handbook/when-any.md       |  287 --
 .../extensions/state-and-testing.md           |    2 +-
 docs/documentation/primitives/signals.md      |    2 +-
 .../reactive-programming/observables.md       |    2 +-
 .../reactive-programming/operators.md         |    2 +-
 nuget-packages.json                           |    1 +
 29 files changed, 16577 insertions(+), 800 deletions(-)
 create mode 100644 docs/documentation/binding/api.md
 create mode 100644 docs/documentation/binding/bindings.md
 create mode 100644 docs/documentation/binding/converters.md
 create mode 100644 docs/documentation/binding/custom-converters.md
 create mode 100644 docs/documentation/binding/index.md
 create mode 100644 docs/documentation/binding/mechanisms.md
 create mode 100644 docs/documentation/binding/observing.md
 create mode 100644 docs/documentation/binding/setup.md
 create mode 100644 docs/documentation/binding/threading.md
 create mode 100644 docs/documentation/binding/unsafe.md
 create mode 100644 docs/documentation/binding/views.md
 delete mode 100644 docs/documentation/handbook/commands/binding-commands.md
 delete mode 100644 docs/documentation/handbook/data-binding/value-converters.md
 delete mode 100644 docs/documentation/handbook/data-binding/windows-forms.md
 delete mode 100644 docs/documentation/handbook/interactions/binding-interactions.md
 delete mode 100644 docs/documentation/handbook/when-any.md

diff --git a/docs/_redirects b/docs/_redirects
index 363476b2..12470cf1 100644
--- a/docs/_redirects
+++ b/docs/_redirects
@@ -1,3 +1,19 @@
+/documentation/handbook/when-any/  /documentation/binding/observing/  301
+/documentation/handbook/when-any  /documentation/binding/observing/  301
+/documentation/handbook/when-any.html  /documentation/binding/observing/  301
+/documentation/handbook/data-binding/value-converters/  /documentation/binding/converters/  301
+/documentation/handbook/data-binding/value-converters  /documentation/binding/converters/  301
+/documentation/handbook/data-binding/value-converters.html  /documentation/binding/converters/  301
+/documentation/handbook/data-binding/windows-forms/  /documentation/binding/threading/  301
+/documentation/handbook/data-binding/windows-forms  /documentation/binding/threading/  301
+/documentation/handbook/data-binding/windows-forms.html  /documentation/binding/threading/  301
+/documentation/handbook/commands/binding-commands/  /documentation/binding/bindings/  301
+/documentation/handbook/commands/binding-commands  /documentation/binding/bindings/  301
+/documentation/handbook/commands/binding-commands.html  /documentation/binding/bindings/  301
+/documentation/handbook/interactions/binding-interactions/  /documentation/binding/bindings/  301
+/documentation/handbook/interactions/binding-interactions  /documentation/binding/bindings/  301
+/documentation/handbook/interactions/binding-interactions.html  /documentation/binding/bindings/  301
+
 # Legacy docfx URLs redirected to mkdocs directory URLs.
 # Catchall while we migrate from docfx (.html) to mkdocs (directory) URLs.
 # Per-page redirects can be added above this line as more granular rules.
diff --git a/docs/documentation/binding/api.md b/docs/documentation/binding/api.md
new file mode 100644
index 00000000..5fb2196f
--- /dev/null
+++ b/docs/documentation/binding/api.md
@@ -0,0 +1,3770 @@
+---
+Order: 11
+---
+# ReactiveUI.Binding API reference
+
+Find types, overloads, parameters, and return values in one place. The tables are grouped by category and topic. Follow a topic link for its walkthrough, examples, and detailed behavior. Use your browser's find command to look up a type or method name.
+
+- [Observing](#observing)
+- [Bindings](#bindings)
+- [Converters](#converters)
+- [Mechanisms](#mechanisms)
+- [Views](#views)
+- [Threading](#threading)
+- [Setup](#setup)
+- [Unsafe and runtime](#unsafe-and-runtime)
+- [Platforms](#platforms)
+
+## Observing
+
+### WhenChanged
+
+[Full description and examples](observing.md).
+
+Types: `ReactiveUI.Binding.ReactiveUIBindingExtensions`.
+
+#### `ReactiveUIBindingExtensions`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class ReactiveUIBindingExtensions` | Extension methods for binding commands from a view model to controls on a view. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `WhenChanged<TObj, T1>(TObj objectToMonitor, Expression<Func<TObj, T1>> property1, string property1Expression = "", string callerFilePath = "", int callerLineNumber = 0)` | Observes a property and emits its current value when subscribed, then its new value after each change that alters it. | `TObj : class`: The type of the object to monitor for property changes; `T1`: The type of the first observed property value; `TObj` `objectToMonitor`: The object instance to observe for property changes; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property1Expression`: The caller argument expression for `property1`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IObservable<T1>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits the current value on subscription and the new value after each change that alters it. |
+| `WhenChanged<TObj, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>(TObj objectToMonitor, Expression<Func<TObj, T1>> property1, Expression<Func<TObj, T2>> property2, Expression<Func<TObj, T3>> property3, Expression<Func<TObj, T4>> property4, Expression<Func<TObj, T5>> property5, Expression<Func<TObj, T6>> property6, Expression<Func<TObj, T7>> property7, Expression<Func<TObj, T8>> property8, Expression<Func<TObj, T9>> property9, Expression<Func<TObj, T10>> property10, Expression<Func<TObj, T11>> property11, Expression<Func<TObj, T12>> property12, Expression<Func<TObj, T13>> property13, Expression<Func<TObj, T14>> property14, Expression<Func<TObj, T15>> property15, Expression<Func<TObj, T16>> property16, string property1Expression = "", string property2Expression = "", string property3Expression = "", string property4Expression = "", string property5Expression = "", string property6Expression = "", string property7Expression = "", string property8Expression = "", string property9Expression = "", string property10Expression = "", string property11Expression = "", string property12Expression = "", string property13Expression = "", string property14Expression = "", string property15Expression = "", string property16Expression = "", string callerFilePath = "", int callerLineNumber = 0)` | Observes 16 properties and emits a PropertyValues of their current values when subscribed and whenever any of them changes. Available for 2 to 16 repeated arguments; the largest form is listed. | `TObj : class`: The type of the object to monitor for property changes; `T1`: The type of the first observed property value; `T2`: The type of the second observed property value; `T3`: The type of the third observed property value; `T4`: The type of the fourth observed property value; `T5`: The type of the fifth observed property value; `T6`: The type of the sixth observed property value; `T7`: The type of the seventh observed property value; `T8`: The type of the eighth observed property value; `T9`: The type of the ninth observed property value; `T10`: The type of the tenth observed property value; `T11`: The type of the eleventh observed property value; `T12`: The type of the twelfth observed property value; `T13`: The type of the thirteenth observed property value; `T14`: The type of the fourteenth observed property value; `T15`: The type of the fifteenth observed property value; `T16`: The type of the sixteenth observed property value; `TObj` `objectToMonitor`: The object instance to observe for property changes; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`Expression<Func<TObj, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects the second property to observe; [`Expression<Func<TObj, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects the third property to observe; [`Expression<Func<TObj, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects the fourth property to observe; [`Expression<Func<TObj, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects the fifth property to observe; [`Expression<Func<TObj, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects the sixth property to observe; [`Expression<Func<TObj, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects the seventh property to observe; [`Expression<Func<TObj, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects the eighth property to observe; [`Expression<Func<TObj, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects the ninth property to observe; [`Expression<Func<TObj, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects the tenth property to observe; [`Expression<Func<TObj, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects the eleventh property to observe; [`Expression<Func<TObj, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects the twelfth property to observe; [`Expression<Func<TObj, T13>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property13`: An expression that selects the thirteenth property to observe; [`Expression<Func<TObj, T14>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property14`: An expression that selects the fourteenth property to observe; [`Expression<Func<TObj, T15>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property15`: An expression that selects the fifteenth property to observe; [`Expression<Func<TObj, T16>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property16`: An expression that selects the sixteenth property to observe; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property1Expression`: The caller argument expression for `property1`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property2Expression`: The caller argument expression for `property2`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property3Expression`: The caller argument expression for `property3`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property4Expression`: The caller argument expression for `property4`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property5Expression`: The caller argument expression for `property5`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property6Expression`: The caller argument expression for `property6`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property7Expression`: The caller argument expression for `property7`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property8Expression`: The caller argument expression for `property8`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property9Expression`: The caller argument expression for `property9`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property10Expression`: The caller argument expression for `property10`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property11Expression`: The caller argument expression for `property11`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property12Expression`: The caller argument expression for `property12`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property13Expression`: The caller argument expression for `property13`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property14Expression`: The caller argument expression for `property14`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property15Expression`: The caller argument expression for `property15`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property16Expression`: The caller argument expression for `property16`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IObservable<PropertyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits a PropertyValues holding the latest value of each property, on subscription and whenever any of them changes. |
+| `WhenChanged<TObj, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TReturn>(TObj objectToMonitor, Expression<Func<TObj, T1>> property1, Expression<Func<TObj, T2>> property2, Expression<Func<TObj, T3>> property3, Expression<Func<TObj, T4>> property4, Expression<Func<TObj, T5>> property5, Expression<Func<TObj, T6>> property6, Expression<Func<TObj, T7>> property7, Expression<Func<TObj, T8>> property8, Expression<Func<TObj, T9>> property9, Expression<Func<TObj, T10>> property10, Expression<Func<TObj, T11>> property11, Expression<Func<TObj, T12>> property12, Expression<Func<TObj, T13>> property13, Expression<Func<TObj, T14>> property14, Expression<Func<TObj, T15>> property15, Expression<Func<TObj, T16>> property16, Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TReturn> conversionFunc, string property1Expression = "", string property2Expression = "", string property3Expression = "", string property4Expression = "", string property5Expression = "", string property6Expression = "", string property7Expression = "", string property8Expression = "", string property9Expression = "", string property10Expression = "", string property11Expression = "", string property12Expression = "", string property13Expression = "", string property14Expression = "", string property15Expression = "", string property16Expression = "", string callerFilePath = "", int callerLineNumber = 0)` | Observes 16 properties and emits the result of applying a conversion function to their current values when subscribed and whenever any of them changes. Available for 2 to 16 repeated arguments; the largest form is listed. | `TObj : class`: The type of the object to monitor for property changes; `T1`: The type of the first observed property value; `T2`: The type of the second observed property value; `T3`: The type of the third observed property value; `T4`: The type of the fourth observed property value; `T5`: The type of the fifth observed property value; `T6`: The type of the sixth observed property value; `T7`: The type of the seventh observed property value; `T8`: The type of the eighth observed property value; `T9`: The type of the ninth observed property value; `T10`: The type of the tenth observed property value; `T11`: The type of the eleventh observed property value; `T12`: The type of the twelfth observed property value; `T13`: The type of the thirteenth observed property value; `T14`: The type of the fourteenth observed property value; `T15`: The type of the fifteenth observed property value; `T16`: The type of the sixteenth observed property value; `TReturn`: The return type of the conversion function; `TObj` `objectToMonitor`: The object instance to observe for property changes; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`Expression<Func<TObj, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects the second property to observe; [`Expression<Func<TObj, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects the third property to observe; [`Expression<Func<TObj, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects the fourth property to observe; [`Expression<Func<TObj, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects the fifth property to observe; [`Expression<Func<TObj, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects the sixth property to observe; [`Expression<Func<TObj, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects the seventh property to observe; [`Expression<Func<TObj, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects the eighth property to observe; [`Expression<Func<TObj, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects the ninth property to observe; [`Expression<Func<TObj, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects the tenth property to observe; [`Expression<Func<TObj, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects the eleventh property to observe; [`Expression<Func<TObj, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects the twelfth property to observe; [`Expression<Func<TObj, T13>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property13`: An expression that selects the thirteenth property to observe; [`Expression<Func<TObj, T14>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property14`: An expression that selects the fourteenth property to observe; [`Expression<Func<TObj, T15>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property15`: An expression that selects the fifteenth property to observe; [`Expression<Func<TObj, T16>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property16`: An expression that selects the sixteenth property to observe; [`Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TReturn>`](https://learn.microsoft.com/dotnet/api/system.func-17) `conversionFunc`: A function that converts the observed property values to the return type; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property1Expression`: The caller argument expression for `property1`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property2Expression`: The caller argument expression for `property2`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property3Expression`: The caller argument expression for `property3`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property4Expression`: The caller argument expression for `property4`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property5Expression`: The caller argument expression for `property5`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property6Expression`: The caller argument expression for `property6`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property7Expression`: The caller argument expression for `property7`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property8Expression`: The caller argument expression for `property8`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property9Expression`: The caller argument expression for `property9`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property10Expression`: The caller argument expression for `property10`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property11Expression`: The caller argument expression for `property11`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property12Expression`: The caller argument expression for `property12`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property13Expression`: The caller argument expression for `property13`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property14Expression`: The caller argument expression for `property14`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property15Expression`: The caller argument expression for `property15`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property16Expression`: The caller argument expression for `property16`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IObservable<TReturn>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits the conversion result on subscription and whenever any of the observed properties changes. |
+
+### WhenChanging
+
+[Full description and examples](observing.md).
+
+Types: `ReactiveUI.Binding.ReactiveUIBindingExtensions`.
+
+#### `ReactiveUIBindingExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `WhenChanging<TObj, T1>(TObj objectToMonitor, Expression<Func<TObj, T1>> property1, string property1Expression = "", string callerFilePath = "", int callerLineNumber = 0)` | Observes a property and emits its current value when subscribed, then the value it holds just before each change. | `TObj : class`: The type of the object to monitor for property changes; `T1`: The type of the first observed property value; `TObj` `objectToMonitor`: The object instance to observe for property changes; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property1Expression`: The caller argument expression for `property1`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IObservable<T1>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits the current value on subscription and the value held before each change. |
+| `WhenChanging<TObj, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>(TObj objectToMonitor, Expression<Func<TObj, T1>> property1, Expression<Func<TObj, T2>> property2, Expression<Func<TObj, T3>> property3, Expression<Func<TObj, T4>> property4, Expression<Func<TObj, T5>> property5, Expression<Func<TObj, T6>> property6, Expression<Func<TObj, T7>> property7, Expression<Func<TObj, T8>> property8, Expression<Func<TObj, T9>> property9, Expression<Func<TObj, T10>> property10, Expression<Func<TObj, T11>> property11, Expression<Func<TObj, T12>> property12, Expression<Func<TObj, T13>> property13, Expression<Func<TObj, T14>> property14, Expression<Func<TObj, T15>> property15, Expression<Func<TObj, T16>> property16, string property1Expression = "", string property2Expression = "", string property3Expression = "", string property4Expression = "", string property5Expression = "", string property6Expression = "", string property7Expression = "", string property8Expression = "", string property9Expression = "", string property10Expression = "", string property11Expression = "", string property12Expression = "", string property13Expression = "", string property14Expression = "", string property15Expression = "", string property16Expression = "", string callerFilePath = "", int callerLineNumber = 0)` | Observes 16 properties and emits a PropertyValues of their values when subscribed and each time one of them is about to change. Available for 2 to 16 repeated arguments; the largest form is listed. | `TObj : class`: The type of the object to monitor for property changes; `T1`: The type of the first observed property value; `T2`: The type of the second observed property value; `T3`: The type of the third observed property value; `T4`: The type of the fourth observed property value; `T5`: The type of the fifth observed property value; `T6`: The type of the sixth observed property value; `T7`: The type of the seventh observed property value; `T8`: The type of the eighth observed property value; `T9`: The type of the ninth observed property value; `T10`: The type of the tenth observed property value; `T11`: The type of the eleventh observed property value; `T12`: The type of the twelfth observed property value; `T13`: The type of the thirteenth observed property value; `T14`: The type of the fourteenth observed property value; `T15`: The type of the fifteenth observed property value; `T16`: The type of the sixteenth observed property value; `TObj` `objectToMonitor`: The object instance to observe for property changes; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`Expression<Func<TObj, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects the second property to observe; [`Expression<Func<TObj, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects the third property to observe; [`Expression<Func<TObj, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects the fourth property to observe; [`Expression<Func<TObj, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects the fifth property to observe; [`Expression<Func<TObj, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects the sixth property to observe; [`Expression<Func<TObj, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects the seventh property to observe; [`Expression<Func<TObj, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects the eighth property to observe; [`Expression<Func<TObj, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects the ninth property to observe; [`Expression<Func<TObj, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects the tenth property to observe; [`Expression<Func<TObj, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects the eleventh property to observe; [`Expression<Func<TObj, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects the twelfth property to observe; [`Expression<Func<TObj, T13>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property13`: An expression that selects the thirteenth property to observe; [`Expression<Func<TObj, T14>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property14`: An expression that selects the fourteenth property to observe; [`Expression<Func<TObj, T15>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property15`: An expression that selects the fifteenth property to observe; [`Expression<Func<TObj, T16>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property16`: An expression that selects the sixteenth property to observe; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property1Expression`: The caller argument expression for `property1`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property2Expression`: The caller argument expression for `property2`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property3Expression`: The caller argument expression for `property3`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property4Expression`: The caller argument expression for `property4`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property5Expression`: The caller argument expression for `property5`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property6Expression`: The caller argument expression for `property6`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property7Expression`: The caller argument expression for `property7`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property8Expression`: The caller argument expression for `property8`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property9Expression`: The caller argument expression for `property9`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property10Expression`: The caller argument expression for `property10`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property11Expression`: The caller argument expression for `property11`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property12Expression`: The caller argument expression for `property12`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property13Expression`: The caller argument expression for `property13`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property14Expression`: The caller argument expression for `property14`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property15Expression`: The caller argument expression for `property15`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property16Expression`: The caller argument expression for `property16`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IObservable<PropertyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits a PropertyValues holding the latest value of each property, on subscription and each time one of them is about to change. |
+| `WhenChanging<TObj, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TReturn>(TObj objectToMonitor, Expression<Func<TObj, T1>> property1, Expression<Func<TObj, T2>> property2, Expression<Func<TObj, T3>> property3, Expression<Func<TObj, T4>> property4, Expression<Func<TObj, T5>> property5, Expression<Func<TObj, T6>> property6, Expression<Func<TObj, T7>> property7, Expression<Func<TObj, T8>> property8, Expression<Func<TObj, T9>> property9, Expression<Func<TObj, T10>> property10, Expression<Func<TObj, T11>> property11, Expression<Func<TObj, T12>> property12, Expression<Func<TObj, T13>> property13, Expression<Func<TObj, T14>> property14, Expression<Func<TObj, T15>> property15, Expression<Func<TObj, T16>> property16, Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TReturn> conversionFunc, string property1Expression = "", string property2Expression = "", string property3Expression = "", string property4Expression = "", string property5Expression = "", string property6Expression = "", string property7Expression = "", string property8Expression = "", string property9Expression = "", string property10Expression = "", string property11Expression = "", string property12Expression = "", string property13Expression = "", string property14Expression = "", string property15Expression = "", string property16Expression = "", string callerFilePath = "", int callerLineNumber = 0)` | Observes 16 properties and emits the result of applying a conversion function to their values when subscribed and each time one of them is about to change. Available for 2 to 16 repeated arguments; the largest form is listed. | `TObj : class`: The type of the object to monitor for property changes; `T1`: The type of the first observed property value; `T2`: The type of the second observed property value; `T3`: The type of the third observed property value; `T4`: The type of the fourth observed property value; `T5`: The type of the fifth observed property value; `T6`: The type of the sixth observed property value; `T7`: The type of the seventh observed property value; `T8`: The type of the eighth observed property value; `T9`: The type of the ninth observed property value; `T10`: The type of the tenth observed property value; `T11`: The type of the eleventh observed property value; `T12`: The type of the twelfth observed property value; `T13`: The type of the thirteenth observed property value; `T14`: The type of the fourteenth observed property value; `T15`: The type of the fifteenth observed property value; `T16`: The type of the sixteenth observed property value; `TReturn`: The return type of the conversion function; `TObj` `objectToMonitor`: The object instance to observe for property changes; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`Expression<Func<TObj, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects the second property to observe; [`Expression<Func<TObj, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects the third property to observe; [`Expression<Func<TObj, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects the fourth property to observe; [`Expression<Func<TObj, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects the fifth property to observe; [`Expression<Func<TObj, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects the sixth property to observe; [`Expression<Func<TObj, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects the seventh property to observe; [`Expression<Func<TObj, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects the eighth property to observe; [`Expression<Func<TObj, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects the ninth property to observe; [`Expression<Func<TObj, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects the tenth property to observe; [`Expression<Func<TObj, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects the eleventh property to observe; [`Expression<Func<TObj, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects the twelfth property to observe; [`Expression<Func<TObj, T13>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property13`: An expression that selects the thirteenth property to observe; [`Expression<Func<TObj, T14>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property14`: An expression that selects the fourteenth property to observe; [`Expression<Func<TObj, T15>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property15`: An expression that selects the fifteenth property to observe; [`Expression<Func<TObj, T16>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property16`: An expression that selects the sixteenth property to observe; [`Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TReturn>`](https://learn.microsoft.com/dotnet/api/system.func-17) `conversionFunc`: A function that converts the observed property values to the return type; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property1Expression`: The caller argument expression for `property1`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property2Expression`: The caller argument expression for `property2`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property3Expression`: The caller argument expression for `property3`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property4Expression`: The caller argument expression for `property4`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property5Expression`: The caller argument expression for `property5`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property6Expression`: The caller argument expression for `property6`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property7Expression`: The caller argument expression for `property7`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property8Expression`: The caller argument expression for `property8`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property9Expression`: The caller argument expression for `property9`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property10Expression`: The caller argument expression for `property10`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property11Expression`: The caller argument expression for `property11`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property12Expression`: The caller argument expression for `property12`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property13Expression`: The caller argument expression for `property13`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property14Expression`: The caller argument expression for `property14`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property15Expression`: The caller argument expression for `property15`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property16Expression`: The caller argument expression for `property16`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IObservable<TReturn>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits the conversion result on subscription and each time one of the observed properties is about to change. |
+
+### WhenAnyValue
+
+[Full description and examples](observing.md).
+
+Types: `ReactiveUI.Binding.ReactiveUIBindingExtensions`.
+
+#### `ReactiveUIBindingExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `WhenAnyValue<TSender, T1>(TSender sender, Expression<Func<TSender, T1>> property1, string property1Expression = "", string callerFilePath = "", int callerLineNumber = 0)` | Observes a property and emits its current value when subscribed, then its new value after each change that alters it. This is a ReactiveUI compatibility shim. | `TSender : class`: The type of the sender to monitor for property changes; `T1`: The type of the first observed property value; `TSender` `sender`: The sender instance to observe for property changes; [`Expression<Func<TSender, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property1Expression`: The caller argument expression for `property1`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IObservable<T1>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits the current value on subscription and the new value after each change that alters it. |
+| `WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>(TSender sender, Expression<Func<TSender, T1>> property1, Expression<Func<TSender, T2>> property2, Expression<Func<TSender, T3>> property3, Expression<Func<TSender, T4>> property4, Expression<Func<TSender, T5>> property5, Expression<Func<TSender, T6>> property6, Expression<Func<TSender, T7>> property7, Expression<Func<TSender, T8>> property8, Expression<Func<TSender, T9>> property9, Expression<Func<TSender, T10>> property10, Expression<Func<TSender, T11>> property11, Expression<Func<TSender, T12>> property12, Expression<Func<TSender, T13>> property13, Expression<Func<TSender, T14>> property14, Expression<Func<TSender, T15>> property15, Expression<Func<TSender, T16>> property16, string property1Expression = "", string property2Expression = "", string property3Expression = "", string property4Expression = "", string property5Expression = "", string property6Expression = "", string property7Expression = "", string property8Expression = "", string property9Expression = "", string property10Expression = "", string property11Expression = "", string property12Expression = "", string property13Expression = "", string property14Expression = "", string property15Expression = "", string property16Expression = "", string callerFilePath = "", int callerLineNumber = 0)` | Observes 16 properties and emits a PropertyValues of their current values when subscribed and whenever any of them changes. This is a ReactiveUI compatibility shim. Available for 2 to 16 repeated arguments; the largest form is listed. | `TSender : class`: The type of the sender to monitor for property changes; `T1`: The type of the first observed property value; `T2`: The type of the second observed property value; `T3`: The type of the third observed property value; `T4`: The type of the fourth observed property value; `T5`: The type of the fifth observed property value; `T6`: The type of the sixth observed property value; `T7`: The type of the seventh observed property value; `T8`: The type of the eighth observed property value; `T9`: The type of the ninth observed property value; `T10`: The type of the tenth observed property value; `T11`: The type of the eleventh observed property value; `T12`: The type of the twelfth observed property value; `T13`: The type of the thirteenth observed property value; `T14`: The type of the fourteenth observed property value; `T15`: The type of the fifteenth observed property value; `T16`: The type of the sixteenth observed property value; `TSender` `sender`: The sender instance to observe for property changes; [`Expression<Func<TSender, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`Expression<Func<TSender, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects the second property to observe; [`Expression<Func<TSender, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects the third property to observe; [`Expression<Func<TSender, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects the fourth property to observe; [`Expression<Func<TSender, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects the fifth property to observe; [`Expression<Func<TSender, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects the sixth property to observe; [`Expression<Func<TSender, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects the seventh property to observe; [`Expression<Func<TSender, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects the eighth property to observe; [`Expression<Func<TSender, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects the ninth property to observe; [`Expression<Func<TSender, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects the tenth property to observe; [`Expression<Func<TSender, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects the eleventh property to observe; [`Expression<Func<TSender, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects the twelfth property to observe; [`Expression<Func<TSender, T13>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property13`: An expression that selects the thirteenth property to observe; [`Expression<Func<TSender, T14>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property14`: An expression that selects the fourteenth property to observe; [`Expression<Func<TSender, T15>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property15`: An expression that selects the fifteenth property to observe; [`Expression<Func<TSender, T16>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property16`: An expression that selects the sixteenth property to observe; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property1Expression`: The caller argument expression for `property1`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property2Expression`: The caller argument expression for `property2`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property3Expression`: The caller argument expression for `property3`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property4Expression`: The caller argument expression for `property4`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property5Expression`: The caller argument expression for `property5`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property6Expression`: The caller argument expression for `property6`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property7Expression`: The caller argument expression for `property7`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property8Expression`: The caller argument expression for `property8`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property9Expression`: The caller argument expression for `property9`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property10Expression`: The caller argument expression for `property10`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property11Expression`: The caller argument expression for `property11`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property12Expression`: The caller argument expression for `property12`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property13Expression`: The caller argument expression for `property13`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property14Expression`: The caller argument expression for `property14`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property15Expression`: The caller argument expression for `property15`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property16Expression`: The caller argument expression for `property16`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IObservable<PropertyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits a PropertyValues holding the latest value of each property, on subscription and whenever any of them changes. |
+| `WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TRet>(TSender sender, Expression<Func<TSender, T1>> property1, Expression<Func<TSender, T2>> property2, Expression<Func<TSender, T3>> property3, Expression<Func<TSender, T4>> property4, Expression<Func<TSender, T5>> property5, Expression<Func<TSender, T6>> property6, Expression<Func<TSender, T7>> property7, Expression<Func<TSender, T8>> property8, Expression<Func<TSender, T9>> property9, Expression<Func<TSender, T10>> property10, Expression<Func<TSender, T11>> property11, Expression<Func<TSender, T12>> property12, Expression<Func<TSender, T13>> property13, Expression<Func<TSender, T14>> property14, Expression<Func<TSender, T15>> property15, Expression<Func<TSender, T16>> property16, Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TRet> selector, string property1Expression = "", string property2Expression = "", string property3Expression = "", string property4Expression = "", string property5Expression = "", string property6Expression = "", string property7Expression = "", string property8Expression = "", string property9Expression = "", string property10Expression = "", string property11Expression = "", string property12Expression = "", string property13Expression = "", string property14Expression = "", string property15Expression = "", string property16Expression = "", string callerFilePath = "", int callerLineNumber = 0)` | Observes 16 properties and emits the result of a selector applied to their current values when subscribed and whenever any of them changes. This is a ReactiveUI compatibility shim. Available for 1 to 16 repeated arguments; the largest form is listed. | `TSender : class`: The type of the sender to monitor for property changes; `T1`: The type of the first observed property value; `T2`: The type of the second observed property value; `T3`: The type of the third observed property value; `T4`: The type of the fourth observed property value; `T5`: The type of the fifth observed property value; `T6`: The type of the sixth observed property value; `T7`: The type of the seventh observed property value; `T8`: The type of the eighth observed property value; `T9`: The type of the ninth observed property value; `T10`: The type of the tenth observed property value; `T11`: The type of the eleventh observed property value; `T12`: The type of the twelfth observed property value; `T13`: The type of the thirteenth observed property value; `T14`: The type of the fourteenth observed property value; `T15`: The type of the fifteenth observed property value; `T16`: The type of the sixteenth observed property value; `TRet`: The return type of the selector function; `TSender` `sender`: The sender instance to observe for property changes; [`Expression<Func<TSender, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`Expression<Func<TSender, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects the second property to observe; [`Expression<Func<TSender, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects the third property to observe; [`Expression<Func<TSender, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects the fourth property to observe; [`Expression<Func<TSender, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects the fifth property to observe; [`Expression<Func<TSender, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects the sixth property to observe; [`Expression<Func<TSender, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects the seventh property to observe; [`Expression<Func<TSender, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects the eighth property to observe; [`Expression<Func<TSender, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects the ninth property to observe; [`Expression<Func<TSender, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects the tenth property to observe; [`Expression<Func<TSender, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects the eleventh property to observe; [`Expression<Func<TSender, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects the twelfth property to observe; [`Expression<Func<TSender, T13>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property13`: An expression that selects the thirteenth property to observe; [`Expression<Func<TSender, T14>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property14`: An expression that selects the fourteenth property to observe; [`Expression<Func<TSender, T15>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property15`: An expression that selects the fifteenth property to observe; [`Expression<Func<TSender, T16>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property16`: An expression that selects the sixteenth property to observe; [`Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TRet>`](https://learn.microsoft.com/dotnet/api/system.func-17) `selector`: A function that converts the observed property values to the return type; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property1Expression`: The caller argument expression for `property1`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property2Expression`: The caller argument expression for `property2`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property3Expression`: The caller argument expression for `property3`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property4Expression`: The caller argument expression for `property4`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property5Expression`: The caller argument expression for `property5`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property6Expression`: The caller argument expression for `property6`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property7Expression`: The caller argument expression for `property7`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property8Expression`: The caller argument expression for `property8`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property9Expression`: The caller argument expression for `property9`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property10Expression`: The caller argument expression for `property10`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property11Expression`: The caller argument expression for `property11`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property12Expression`: The caller argument expression for `property12`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property13Expression`: The caller argument expression for `property13`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property14Expression`: The caller argument expression for `property14`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property15Expression`: The caller argument expression for `property15`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property16Expression`: The caller argument expression for `property16`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IObservable<TRet>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits the selector result on subscription and whenever any of the observed properties changes. |
+
+### WhenAny
+
+[Full description and examples](observing.md).
+
+Types: `ReactiveUI.Binding.ReactiveUIBindingExtensions`.
+
+#### `ReactiveUIBindingExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(TSender sender, Expression<Func<TSender, T1>> property1, Expression<Func<TSender, T2>> property2, Expression<Func<TSender, T3>> property3, Expression<Func<TSender, T4>> property4, Expression<Func<TSender, T5>> property5, Expression<Func<TSender, T6>> property6, Expression<Func<TSender, T7>> property7, Expression<Func<TSender, T8>> property8, Expression<Func<TSender, T9>> property9, Expression<Func<TSender, T10>> property10, Expression<Func<TSender, T11>> property11, Expression<Func<TSender, T12>> property12, Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, IObservedChange<TSender, T7>, IObservedChange<TSender, T8>, IObservedChange<TSender, T9>, IObservedChange<TSender, T10>, IObservedChange<TSender, T11>, IObservedChange<TSender, T12>, TRet> selector, string property1Expression = "", string property2Expression = "", string property3Expression = "", string property4Expression = "", string property5Expression = "", string property6Expression = "", string property7Expression = "", string property8Expression = "", string property9Expression = "", string property10Expression = "", string property11Expression = "", string property12Expression = "", string callerFilePath = "", int callerLineNumber = 0)` | Observes 12 properties and emits the selector applied to their observed changes, on subscription and whenever any of them changes. Available for 1 to 12 repeated arguments; the largest form is listed. | `TSender : class`: The type of the sender to monitor for property changes; `TRet`: The return type of the selector; `T1`: The type of property 1 value; `T2`: The type of property 2 value; `T3`: The type of property 3 value; `T4`: The type of property 4 value; `T5`: The type of property 5 value; `T6`: The type of property 6 value; `T7`: The type of property 7 value; `T8`: The type of property 8 value; `T9`: The type of property 9 value; `T10`: The type of property 10 value; `T11`: The type of property 11 value; `T12`: The type of property 12 value; `TSender` `sender`: The sender instance to observe for property changes; [`Expression<Func<TSender, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects property 1 to observe; [`Expression<Func<TSender, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects property 2 to observe; [`Expression<Func<TSender, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects property 3 to observe; [`Expression<Func<TSender, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects property 4 to observe; [`Expression<Func<TSender, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects property 5 to observe; [`Expression<Func<TSender, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects property 6 to observe; [`Expression<Func<TSender, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects property 7 to observe; [`Expression<Func<TSender, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects property 8 to observe; [`Expression<Func<TSender, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects property 9 to observe; [`Expression<Func<TSender, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects property 10 to observe; [`Expression<Func<TSender, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects property 11 to observe; [`Expression<Func<TSender, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects property 12 to observe; [`Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, IObservedChange<TSender, T7>, IObservedChange<TSender, T8>, IObservedChange<TSender, T9>, IObservedChange<TSender, T10>, IObservedChange<TSender, T11>, IObservedChange<TSender, T12>, TRet>`](https://learn.microsoft.com/dotnet/api/system.func-13) `selector`: A function that combines the observed changes into a result; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property1Expression`: The caller argument expression for `property1`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property2Expression`: The caller argument expression for `property2`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property3Expression`: The caller argument expression for `property3`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property4Expression`: The caller argument expression for `property4`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property5Expression`: The caller argument expression for `property5`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property6Expression`: The caller argument expression for `property6`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property7Expression`: The caller argument expression for `property7`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property8Expression`: The caller argument expression for `property8`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property9Expression`: The caller argument expression for `property9`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property10Expression`: The caller argument expression for `property10`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property11Expression`: The caller argument expression for `property11`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `property12Expression`: The caller argument expression for `property12`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IObservable<TRet>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of selector results, emitted on subscription and whenever an observed property changes. |
+| `WhenAnyDynamic<TSender, TRet>(TSender sender, Expression? property1, Expression? property2, Expression? property3, Expression? property4, Expression? property5, Expression? property6, Expression? property7, Expression? property8, Expression? property9, Expression? property10, Expression? property11, Expression? property12, Func<IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, TRet> selector)` | Observes 12 property chains named by run-time expressions and emits the selector applied to their observed changes, on subscription and whenever any of them changes. Available for 1 to 12 repeated arguments; the largest form is listed. | `TSender : class`: The type of the object the chains are rooted on; `TRet`: The type of the projected result; `TSender` `sender`: The object the chains are rooted on; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property1`: An expression naming property 1; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property2`: An expression naming property 2; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property3`: An expression naming property 3; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property4`: An expression naming property 4; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property5`: An expression naming property 5; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property6`: An expression naming property 6; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property7`: An expression naming property 7; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property8`: An expression naming property 8; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property9`: An expression naming property 9; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property10`: An expression naming property 10; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property11`: An expression naming property 11; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property12`: An expression naming property 12; [`Func<IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, TRet>`](https://learn.microsoft.com/dotnet/api/system.func-13) `selector`: Projects the observed changes into a result | [`IObservable<TRet>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of selector results. |
+| `WhenAnyDynamic<TSender, TRet>(TSender sender, Expression? property1, Expression? property2, Expression? property3, Expression? property4, Expression? property5, Expression? property6, Expression? property7, Expression? property8, Expression? property9, Expression? property10, Expression? property11, Expression? property12, Func<IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, TRet> selector, bool isDistinct)` | Observes 12 property chains named by run-time expressions and emits the selector applied to their observed changes, on subscription and whenever any of them changes. Available for 1 to 12 repeated arguments; the largest form is listed. | `TSender : class`: The type of the object the chains are rooted on; `TRet`: The type of the projected result; `TSender` `sender`: The object the chains are rooted on; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property1`: An expression naming property 1; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property2`: An expression naming property 2; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property3`: An expression naming property 3; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property4`: An expression naming property 4; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property5`: An expression naming property 5; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property6`: An expression naming property 6; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property7`: An expression naming property 7; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property8`: An expression naming property 8; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property9`: An expression naming property 9; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property10`: An expression naming property 10; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property11`: An expression naming property 11; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `property12`: An expression naming property 12; [`Func<IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, IObservedChange<TSender, object?>, TRet>`](https://learn.microsoft.com/dotnet/api/system.func-13) `selector`: Projects the observed changes into a result; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `isDistinct`: Whether a chain reports only when its value changes | [`IObservable<TRet>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of selector results. |
+
+### WhenAnyObservable
+
+[Full description and examples](observing.md).
+
+Types: `ReactiveUI.Binding.ReactiveUIBindingExtensions`.
+
+#### `ReactiveUIBindingExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `WhenAnyObservable<TSender, TRet>(TSender sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7, Expression<Func<TSender, IObservable<TRet>?>> obs8, Expression<Func<TSender, IObservable<TRet>?>> obs9, Expression<Func<TSender, IObservable<TRet>?>> obs10, Expression<Func<TSender, IObservable<TRet>?>> obs11, Expression<Func<TSender, IObservable<TRet>?>> obs12, string obs1Expression = "", string obs2Expression = "", string obs3Expression = "", string obs4Expression = "", string obs5Expression = "", string obs6Expression = "", string obs7Expression = "", string obs8Expression = "", string obs9Expression = "", string obs10Expression = "", string obs11Expression = "", string obs12Expression = "", string callerFilePath = "", int callerLineNumber = 0)` | Observes 12 observable properties and merges the values of the observables they hold, switching each when its property changes; a null value emits nothing. Available for 1 to 12 repeated arguments; the largest form is listed. | `TSender : class`: The type of the sender to monitor for property changes; `TRet`: The element type of the observed observables; `TSender` `sender`: The sender instance to observe for property changes; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs1`: An expression that selects observable property 1 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs2`: An expression that selects observable property 2 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs3`: An expression that selects observable property 3 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs4`: An expression that selects observable property 4 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs5`: An expression that selects observable property 5 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs6`: An expression that selects observable property 6 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs7`: An expression that selects observable property 7 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs8`: An expression that selects observable property 8 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs9`: An expression that selects observable property 9 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs10`: An expression that selects observable property 10 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs11`: An expression that selects observable property 11 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs12`: An expression that selects observable property 12 to observe; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs1Expression`: The caller argument expression for `obs1`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs2Expression`: The caller argument expression for `obs2`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs3Expression`: The caller argument expression for `obs3`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs4Expression`: The caller argument expression for `obs4`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs5Expression`: The caller argument expression for `obs5`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs6Expression`: The caller argument expression for `obs6`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs7Expression`: The caller argument expression for `obs7`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs8Expression`: The caller argument expression for `obs8`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs9Expression`: The caller argument expression for `obs9`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs10Expression`: The caller argument expression for `obs10`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs11Expression`: The caller argument expression for `obs11`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs12Expression`: The caller argument expression for `obs12`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IObservable<TRet>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits the values of the latest observable each property held, merged into one sequence. |
+| `WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(TSender sender, Expression<Func<TSender, IObservable<T1>?>> obs1, Expression<Func<TSender, IObservable<T2>?>> obs2, Expression<Func<TSender, IObservable<T3>?>> obs3, Expression<Func<TSender, IObservable<T4>?>> obs4, Expression<Func<TSender, IObservable<T5>?>> obs5, Expression<Func<TSender, IObservable<T6>?>> obs6, Expression<Func<TSender, IObservable<T7>?>> obs7, Expression<Func<TSender, IObservable<T8>?>> obs8, Expression<Func<TSender, IObservable<T9>?>> obs9, Expression<Func<TSender, IObservable<T10>?>> obs10, Expression<Func<TSender, IObservable<T11>?>> obs11, Expression<Func<TSender, IObservable<T12>?>> obs12, Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet> selector, string obs1Expression = "", string obs2Expression = "", string obs3Expression = "", string obs4Expression = "", string obs5Expression = "", string obs6Expression = "", string obs7Expression = "", string obs8Expression = "", string obs9Expression = "", string obs10Expression = "", string obs11Expression = "", string obs12Expression = "", string callerFilePath = "", int callerLineNumber = 0)` | Observes 12 observable properties of different element types and emits the selector applied to the latest value of each, once every observable has produced a value. Available for 2 to 12 repeated arguments; the largest form is listed. | `TSender : class`: The type of the sender to monitor for property changes; `TRet`: The return type of the selector; `T1`: The element type of observable property 1; `T2`: The element type of observable property 2; `T3`: The element type of observable property 3; `T4`: The element type of observable property 4; `T5`: The element type of observable property 5; `T6`: The element type of observable property 6; `T7`: The element type of observable property 7; `T8`: The element type of observable property 8; `T9`: The element type of observable property 9; `T10`: The element type of observable property 10; `T11`: The element type of observable property 11; `T12`: The element type of observable property 12; `TSender` `sender`: The sender instance to observe for property changes; [`Expression<Func<TSender, IObservable<T1>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs1`: An expression that selects observable property 1 to observe; [`Expression<Func<TSender, IObservable<T2>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs2`: An expression that selects observable property 2 to observe; [`Expression<Func<TSender, IObservable<T3>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs3`: An expression that selects observable property 3 to observe; [`Expression<Func<TSender, IObservable<T4>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs4`: An expression that selects observable property 4 to observe; [`Expression<Func<TSender, IObservable<T5>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs5`: An expression that selects observable property 5 to observe; [`Expression<Func<TSender, IObservable<T6>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs6`: An expression that selects observable property 6 to observe; [`Expression<Func<TSender, IObservable<T7>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs7`: An expression that selects observable property 7 to observe; [`Expression<Func<TSender, IObservable<T8>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs8`: An expression that selects observable property 8 to observe; [`Expression<Func<TSender, IObservable<T9>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs9`: An expression that selects observable property 9 to observe; [`Expression<Func<TSender, IObservable<T10>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs10`: An expression that selects observable property 10 to observe; [`Expression<Func<TSender, IObservable<T11>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs11`: An expression that selects observable property 11 to observe; [`Expression<Func<TSender, IObservable<T12>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs12`: An expression that selects observable property 12 to observe; [`Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet>`](https://learn.microsoft.com/dotnet/api/system.func-13) `selector`: A function that combines the latest values from all observables; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs1Expression`: The caller argument expression for `obs1`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs2Expression`: The caller argument expression for `obs2`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs3Expression`: The caller argument expression for `obs3`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs4Expression`: The caller argument expression for `obs4`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs5Expression`: The caller argument expression for `obs5`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs6Expression`: The caller argument expression for `obs6`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs7Expression`: The caller argument expression for `obs7`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs8Expression`: The caller argument expression for `obs8`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs9Expression`: The caller argument expression for `obs9`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs10Expression`: The caller argument expression for `obs10`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs11Expression`: The caller argument expression for `obs11`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `obs12Expression`: The caller argument expression for `obs12`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IObservable<TRet>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits the selector result each time one of the observables produces a value, once every observable has produced one. |
+
+### Property paths
+
+[Full description and examples](observing.md).
+
+Types: `ReactiveUI.Binding.ExpressionChainParameters<TSender>`, `ReactiveUI.Binding.Expressions.ExpressionMixins`, `ReactiveUI.Binding.Expressions.Reflection`, `ReactiveUI.Binding.ObservableForProperty.ExpressionChainSink<TSender, TValue>`, `ReactiveUI.Binding.ObservableForProperty.ObservableForPropertySink<TSender, TValue>`, `ReactiveUI.Binding.ObservableForProperty.ReactiveNotifyPropertyChangedMixins`.
+
+#### `ExpressionChainParameters<TSender>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `readonly struct ExpressionChainParameters<TSender>` | How one chain of property accesses is to be observed. | `TSender`: The root sender type surfaced on the emitted change | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ExpressionChainParameters(TSender? Source, Expression? Expression, Expression[] Links, bool BeforeChange, bool SkipInitial, bool IsDistinct, bool SuppressWarnings)` | How one chain of property accesses is to be observed. | `TSender?` `Source`: The root object of the chain; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `Expression`: The full expression surfaced on the emitted change; [`Expression[]`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `Links`: The member-access links of the chain, in order; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `BeforeChange`: Whether values are observed before they change; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `SkipInitial`: Whether the first value the chain produces is dropped; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `IsDistinct`: Whether consecutive equal leaf values are suppressed; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `SuppressWarnings`: Whether the warning a property with no notification mechanism raises is suppressed | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BeforeChange { get; init; }` | Whether values are observed before they change. | None. | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) |
+| `Expression { get; init; }` | The full expression surfaced on the emitted change. | None. | [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) |
+| `IsDistinct { get; init; }` | Whether consecutive equal leaf values are suppressed. | None. | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) |
+| `Links { get; init; }` | The member-access links of the chain, in order. | None. | [`Expression[]`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) |
+| `SkipInitial { get; init; }` | Whether the first value the chain produces is dropped. | None. | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) |
+| `Source { get; init; }` | The root object of the chain. | None. | `TSender?` |
+| `SuppressWarnings { get; init; }` | Whether the warning a property with no notification mechanism raises is suppressed. | None. | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) |
+
+#### `ExpressionMixins`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class ExpressionMixins` | Extension methods that decompose property-access expression trees. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Expression.GetArgumentsArray()` | Gets the constant arguments passed to an indexer expression. | [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression` (receiver) | [`object?[]?`](https://learn.microsoft.com/dotnet/api/system.object): The argument values, or null when the expression is not an index expression. |
+| `Expression.GetExpressionChain()` | Gets the member accesses and indexer accesses that make up an expression, ordered from the root parameter outward. | [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression` (receiver) | [`IEnumerable<Expression>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1): The links in order, each rebased onto a fresh parameter of its parent's type; empty when the expression is a parameter or `null`. |
+| `Expression.GetMemberInfo()` | Gets the member an index or member-access expression names, looking through conversions. | [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression` (receiver) | [`MemberInfo?`](https://learn.microsoft.com/dotnet/api/system.reflection.memberinfo): The property, field or indexer the expression names. |
+| `Expression.GetParent()` | Gets the expression an index or member-access expression is read from. | [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression` (receiver) | [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression): The object expression, or null for a static member. |
+
+#### `Reflection`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class Reflection` | Reads and writes members along a property expression chain by reflection. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ExpressionToPropertyNames(Expression? expression)` | Converts an expression that points to a property chain into a dotted path string, such as `A.B[0].C`. | [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The expression to generate the property names from; an indexer's arguments must be constants | [`string`](https://learn.microsoft.com/dotnet/api/system.string): The member names joined by dots, with an indexer written as its name followed by its arguments in brackets. |
+| `GetValueFetcherForProperty(MemberInfo? member)` | Converts a [`MemberInfo`](https://learn.microsoft.com/dotnet/api/system.reflection.memberinfo) into a delegate which fetches the value for the member. | [`MemberInfo?`](https://learn.microsoft.com/dotnet/api/system.reflection.memberinfo) `member`: The member info to convert | [`Func<object?, object?[]?, object?>?`](https://learn.microsoft.com/dotnet/api/system.func-3): A delegate that fetches the value, or null when the member is neither a field nor a property. The delegate for a field throws [`InvalidOperationException`](https://learn.microsoft.com/dotnet/api/system.invalidoperationexception) when the field holds null. |
+| `GetValueFetcherOrThrow(MemberInfo? member)` | Converts a [`MemberInfo`](https://learn.microsoft.com/dotnet/api/system.reflection.memberinfo) into a delegate which fetches the value for the member. Throws if the member is not a field or property. | [`MemberInfo?`](https://learn.microsoft.com/dotnet/api/system.reflection.memberinfo) `member`: The member info to convert | [`Func<object?, object?[]?, object?>`](https://learn.microsoft.com/dotnet/api/system.func-3): A delegate that fetches the value. |
+| `GetValueSetterForProperty(MemberInfo? member)` | Converts a [`MemberInfo`](https://learn.microsoft.com/dotnet/api/system.reflection.memberinfo) into a delegate which sets the value for the member. | [`MemberInfo?`](https://learn.microsoft.com/dotnet/api/system.reflection.memberinfo) `member`: The member info to convert | [`Action<object?, object?, object?[]?>?`](https://learn.microsoft.com/dotnet/api/system.action-3): A delegate that sets the value, or null when the member is neither a field nor a property. |
+| `GetValueSetterOrThrow(MemberInfo? member)` | Converts a [`MemberInfo`](https://learn.microsoft.com/dotnet/api/system.reflection.memberinfo) into a delegate which sets the value for the member. Throws if the member is not a field or property. | [`MemberInfo?`](https://learn.microsoft.com/dotnet/api/system.reflection.memberinfo) `member`: The member info to convert | [`Action<object?, object?, object?[]?>`](https://learn.microsoft.com/dotnet/api/system.action-3): A delegate that sets the value. |
+| `Rewrite(Expression? expression)` | Simplifies an expression with the shared expression rewriter. | [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The expression to rewrite | [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression): The rewritten expression, or `null` when `expression` is `null`. |
+| `TryGetAllValuesForPropertyChain(out IObservedChange<object, object?>[] changeValues, object? current, IEnumerable<Expression> expressionChain)` | Attempts to get all intermediate values in a property chain as observed changes. | out [`IObservedChange<object, object?>[]`](observing.md) `changeValues`: Receives an array with one entry per expression in the chain; the entries from the first null link onward are null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `current`: The object that starts the property chain; [`IEnumerable<Expression>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1) `expressionChain`: A sequence of expressions that point to properties/fields | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): True if all values were retrieved; false when `current` or a property partway along the chain is null. |
+| `TryGetValueForPropertyChain<TValue>(out TValue changeValue, object? current, IEnumerable<Expression> expressionChain)` | Attempts to get the value of the last property in an expression chain. | `TValue`: The expected type of the final value; out `TValue` `changeValue`: Receives the value if the chain can be evaluated; otherwise the default; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `current`: The object that starts the property chain; [`IEnumerable<Expression>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1) `expressionChain`: A sequence of expressions that point to properties/fields | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): True if the value was retrieved; false when `current` or a property partway along the chain is null. |
+| `TrySetValueToPropertyChain<TValue>(object? target, IEnumerable<Expression> expressionChain, TValue value)` | Attempts to set the value of the last property in an expression chain, throwing when a chain member is not a field or property. | `TValue`: The type of the end value being set; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `target`: The object that starts the property chain; [`IEnumerable<Expression>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1) `expressionChain`: A sequence of expressions that point to properties/fields; `TValue` `value`: The value to set on the last property in the chain | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): True if the value was set; false when the object owning the last property is null. |
+| `TrySetValueToPropertyChain<TValue>(object? target, IEnumerable<Expression> expressionChain, TValue value, bool shouldThrow)` | Attempts to set the value of the last property in an expression chain. | `TValue`: The type of the end value being set; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `target`: The object that starts the property chain; [`IEnumerable<Expression>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1) `expressionChain`: A sequence of expressions that point to properties/fields; `TValue` `value`: The value to set on the last property in the chain; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `shouldThrow`: If true, throw when a chain member is not a field or property; otherwise, an unreadable link is skipped and an unwritable last member returns false | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): True if the value was set; false when the object owning the last property is null or the last member cannot be written. |
+
+#### `ExpressionChainSink<TSender, TValue>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ExpressionChainSink<TSender, TValue>` | Observes the leaf of an expression member chain (`x.A.B.C`) and emits its value as an observed change each time any link changes. | `TSender`: The root sender type surfaced on the emitted change; `TValue`: The leaf value type | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ExpressionChainSink(TSender? source, Expression? expression, Expression[] links, bool beforeChange, bool skipInitial, bool isDistinct, bool suppressWarnings)` | Initializes a new instance of the [`ExpressionChainSink<TSender, TValue>`](observing.md) class. | `TSender?` `source`: The root object of the chain; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The full expression surfaced on the emitted change; [`Expression[]`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `links`: The member-access links of the chain, in order; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChange`: Whether values are observed before they change; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `skipInitial`: Whether the first value the chain produces is dropped; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `isDistinct`: Whether consecutive equal leaf values are suppressed; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `suppressWarnings`: Whether the warning a property with no notification mechanism raises is suppressed | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Subscribe(IObserver<IObservedChange<TSender, TValue>> observer)` | Notifies the provider that an observer is to receive notifications. | [`IObserver<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobserver-1) `observer`: The object that is to receive notifications | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A reference to an interface that allows observers to stop receiving notifications before the provider has finished sending them. |
+
+#### `ObservableForPropertySink<TSender, TValue>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ObservableForPropertySink<TSender, TValue>` | Emits a property's value on subscribe, unless skipped, and again on each notification. | `TSender`: The type of the observed object surfaced on the emitted change; `TValue`: The property value type | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ObservableForPropertySink(TSender sender, Expression expression, IObservable<IObservedChange<object, object?>> notifications, Func<TValue> readValue, bool skipInitial, bool isDistinct)` | Initializes a new instance of the [`ObservableForPropertySink<TSender, TValue>`](observing.md) class. | `TSender` `sender`: The observed object surfaced on the emitted change; [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The expression surfaced on the emitted change; [`IObservable<IObservedChange<object, object?>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `notifications`: The underlying change-notification source; [`Func<TValue>`](https://learn.microsoft.com/dotnet/api/system.func-1) `readValue`: Reads the current property value from the sender; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `skipInitial`: When `true`, the current value is not emitted on subscribe; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `isDistinct`: When `true`, consecutive equal values are suppressed | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Subscribe(IObserver<IObservedChange<TSender, TValue>> observer)` | Notifies the provider that an observer is to receive notifications. | [`IObserver<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobserver-1) `observer`: The object that is to receive notifications | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A reference to an interface that allows observers to stop receiving notifications before the provider has finished sending them. |
+
+#### `ReactiveNotifyPropertyChangedMixins`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class ReactiveNotifyPropertyChangedMixins` | Extension methods that observe a property, by name or through an expression chain, using the [`ICreatesObservableForProperty`](mechanisms.md) registrations from the service locator. Generated code does not call them. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ObservableForProperty<TSender, TValue>(TSender? item, Expression<Func<TSender, TValue>> property)` | Observes the property an expression points at after it changes, emitting its current value first and dropping consecutive equal values. | `TSender`; `TValue`: The value type; `TSender?` `item`; [`Expression<Func<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: An Expression representing the property | [`IObservable<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of the changes for the property. |
+| `ObservableForProperty<TSender, TValue>(TSender? item, string propertyName)` | Observes a property by name after it changes, emitting its current value first and dropping consecutive equal values. | `TSender`; `TValue`: The value type; `TSender?` `item`; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name to observe | [`IObservable<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of the changes for the property. |
+| `ObservableForProperty<TSender, TValue>(TSender? item, Expression<Func<TSender, TValue>> property, bool skipInitial)` | Observes the property an expression points at after it changes, dropping consecutive equal values and optionally skipping the current value emitted on subscription. | `TSender`; `TValue`: The value type; `TSender?` `item`; [`Expression<Func<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: An Expression representing the property; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `skipInitial`: If true, the Observable will not notify with the initial value | [`IObservable<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of the changes for the property. |
+| `ObservableForProperty<TSender, TValue>(TSender? item, string propertyName, bool skipInitial)` | Observes a property by name after it changes, dropping consecutive equal values and optionally skipping the current value emitted on subscription. | `TSender`; `TValue`: The value type; `TSender?` `item`; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name to observe; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `skipInitial`: If true, the Observable will not notify with the initial value | [`IObservable<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of the changes for the property. |
+| `ObservableForProperty<TSender, TValue>(TSender? item, Expression<Func<TSender, TValue>> property, bool beforeChange, bool skipInitial, bool isDistinct)` | Observes the property, or the member chain, an expression points at. | `TSender`; `TValue`: The value type; `TSender?` `item`; [`Expression<Func<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: An Expression representing the property; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChange`: If true, the Observable will notify immediately before a property is going to change; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `skipInitial`: If true, the Observable will not notify with the initial value; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `isDistinct`: If set to true, values are filtered with DistinctUntilChanged | [`IObservable<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of the changes for the last link of the chain. |
+| `ObservableForProperty<TSender, TValue>(TSender? item, string propertyName, bool beforeChange, bool skipInitial, bool isDistinct)` | Observes a property by name through the highest-affinity [`ICreatesObservableForProperty`](mechanisms.md) registered for the source's runtime type. | `TSender`; `TValue`: The value type; `TSender?` `item`; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name to observe; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChange`: If true, the Observable will notify immediately before a property is going to change; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `skipInitial`: If true, the Observable will not notify with the initial value; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `isDistinct`: If set to true, values are filtered with DistinctUntilChanged | [`IObservable<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of the changes for the property; each value is read by reflection from the public instance property, or is the default when that is missing or null. |
+| `SubscribeToExpressionChain<TSender, TValue>(TSender? item, Expression? expression)` | Observes an expression's member chain after each link changes, emitting the end value first and dropping consecutive equal values. | `TSender`; `TValue`: The end value we want to subscribe to; `TSender?` `item`; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: An expression which will point towards the property | [`IObservable<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable which notifies about observed changes. |
+| `SubscribeToExpressionChain<TSender, TValue>(TSender? item, Expression? expression, bool skipInitial)` | Observes an expression's member chain after each link changes, dropping consecutive equal values and optionally skipping the end value emitted on subscription. | `TSender`; `TValue`: The end value we want to subscribe to; `TSender?` `item`; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: An expression which will point towards the property; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `skipInitial`: If we don't want to get a notification about the default value of the property | [`IObservable<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable which notifies about observed changes. |
+| `SubscribeToExpressionChain<TSender, TValue>(TSender? item, Expression? expression, bool beforeChange, bool skipInitial, bool isDistinct)` | Observes each property in an expression's member chain, re-subscribing deeper links when an intermediate value changes, and reports the value at the end of the chain. | `TSender`; `TValue`: The end value we want to subscribe to; `TSender?` `item`; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: An expression which will point towards the property; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChange`: If we are interested in notifications before the property value is changed; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `skipInitial`: If we don't want to get a notification about the default value of the property; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `isDistinct`: If set to true, values are filtered with DistinctUntilChanged | [`IObservable<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable which notifies about observed changes. |
+| `SubscribeToExpressionChain<TSender, TValue>(TSender? item, Expression? expression, bool beforeChange, bool skipInitial, bool isDistinct, bool suppressWarnings)` | Observes each property in an expression's member chain, re-subscribing deeper links when an intermediate value changes, and reports the value at the end of the chain. | `TSender`; `TValue`: The end value we want to subscribe to; `TSender?` `item`; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: An expression which will point towards the property; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChange`: If we are interested in notifications before the property value is changed; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `skipInitial`: If we don't want to get a notification about the default value of the property; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `isDistinct`: If set to true, values are filtered with DistinctUntilChanged; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `suppressWarnings`: If set to true, a property that cannot notify is observed quietly | [`IObservable<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable which notifies about observed changes. |
+
+### Observed changes
+
+[Full description and examples](observing.md).
+
+Types: `ReactiveUI.Binding.IObservedChange<TSender, TValue>`, `ReactiveUI.Binding.ObservableForProperty.ObservedChangedMixins`, `ReactiveUI.Binding.ObservedChange<TSender, TValue>`.
+
+#### `IObservedChange<TSender, TValue>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IObservedChange<TSender, TValue>` | Describes one property change: the object that raised it, the expression naming the property, and its value. | `TSender`: The type of the object that raised the change; `TValue`: The type of the property value | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Expression { get; }` | Gets the expression of the member that changed. | None. | [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) |
+| `Sender { get; }` | Gets the object that raised the change. | None. | `TSender` |
+| `Value { get; }` | Gets the value the change carries; a source that raises a notification without reading the property leaves it at the default. | None. | `TValue` |
+
+#### `ObservedChangedMixins`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class ObservedChangedMixins` | A collection of helpers for [`IObservedChange<TSender, TValue>`](observing.md). | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `IObservedChange<TSender, TValue>.GetPropertyName<TSender, TValue>()` | Returns the dotted path of the property the change describes, such as `A.B[0].C`. | `TSender`; `TValue`; [`IObservedChange<TSender, TValue>`](observing.md) `item` (receiver) | [`string`](https://learn.microsoft.com/dotnet/api/system.string): The property path built from the change's expression. |
+| `IObservedChange<TSender, TValue>.GetValue<TSender, TValue>()` | Returns the value carried by the change, or reads it from the sender through the change's expression when the carried value is the default. | `TSender`; `TValue`; [`IObservedChange<TSender, TValue>`](observing.md) `item` (receiver) | `TValue`: The current value of the property. |
+| `IObservedChange<TSender, TValue>.GetValueOrDefault<TSender, TValue>()` | Returns the value `GetValue` would return, or the default when a property partway along the expression is `null`. | `TSender`; `TValue`; [`IObservedChange<TSender, TValue>`](observing.md) `item` (receiver) | `TValue?`: The current value of the property, or default. |
+| `IObservable<IObservedChange<TSender, TValue>>.Value<TSender, TValue>()` | Projects each observed change to the current value of the property it describes. | `TSender`; `TValue`; [`IObservable<IObservedChange<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `stream` (receiver) | [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of the current values; a change whose expression cannot be followed faults it with an [`InvalidOperationException`](https://learn.microsoft.com/dotnet/api/system.invalidoperationexception). |
+
+#### `ObservedChange<TSender, TValue>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `class ObservedChange<TSender, TValue>` | Concrete implementation of [`IObservedChange<TSender, TValue>`](observing.md). | `TSender`: The type of the object that raised the change; `TValue`: The type of the property value | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ObservedChange(TSender sender, Expression? expression, TValue value)` | Initializes a new instance of the [`ObservedChange<TSender, TValue>`](observing.md) class. | `TSender` `sender`: The object that raised the change; [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The expression of the member that changed; `TValue` `value`: The value of the property; the default when the reader is to fetch it from `sender` | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Expression { get; }` | Gets the expression of the member that changed. | None. | [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) |
+| `Sender { get; }` | Gets the object that raised the change. | None. | `TSender` |
+| `Value { get; }` | Gets the value the change carries; a source that raises a notification without reading the property leaves it at the default. | None. | `TValue` |
+
+### Property values
+
+[Full description and examples](observing.md).
+
+Types: `ReactiveUI.Binding.PropertyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>`.
+
+#### `PropertyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `readonly struct PropertyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>` | The values of 16 observed properties, as one emission. Available for 2 to 16 type arguments; the largest form is listed. | `T1`: The type of the first observed property; `T2`: The type of the second observed property; `T3`: The type of the third observed property; `T4`: The type of the fourth observed property; `T5`: The type of the fifth observed property; `T6`: The type of the sixth observed property; `T7`: The type of the seventh observed property; `T8`: The type of the eighth observed property; `T9`: The type of the ninth observed property; `T10`: The type of the tenth observed property; `T11`: The type of the eleventh observed property; `T12`: The type of the twelfth observed property; `T13`: The type of the thirteenth observed property; `T14`: The type of the fourteenth observed property; `T15`: The type of the fifteenth observed property; `T16`: The type of the sixteenth observed property | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `PropertyValues(T1 Property1, T2 Property2, T3 Property3, T4 Property4, T5 Property5, T6 Property6, T7 Property7, T8 Property8, T9 Property9, T10 Property10, T11 Property11, T12 Property12, T13 Property13, T14 Property14, T15 Property15, T16 Property16)` | The values of 16 observed properties, as one emission. | `T1` `Property1`: The value of the first observed property; `T2` `Property2`: The value of the second observed property; `T3` `Property3`: The value of the third observed property; `T4` `Property4`: The value of the fourth observed property; `T5` `Property5`: The value of the fifth observed property; `T6` `Property6`: The value of the sixth observed property; `T7` `Property7`: The value of the seventh observed property; `T8` `Property8`: The value of the eighth observed property; `T9` `Property9`: The value of the ninth observed property; `T10` `Property10`: The value of the tenth observed property; `T11` `Property11`: The value of the eleventh observed property; `T12` `Property12`: The value of the twelfth observed property; `T13` `Property13`: The value of the thirteenth observed property; `T14` `Property14`: The value of the fourteenth observed property; `T15` `Property15`: The value of the fifteenth observed property; `T16` `Property16`: The value of the sixteenth observed property | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Property1 { get; init; }` | The value of the first observed property. | None. | `T1` |
+| `Property10 { get; init; }` | The value of the tenth observed property. | None. | `T10` |
+| `Property11 { get; init; }` | The value of the eleventh observed property. | None. | `T11` |
+| `Property12 { get; init; }` | The value of the twelfth observed property. | None. | `T12` |
+| `Property13 { get; init; }` | The value of the thirteenth observed property. | None. | `T13` |
+| `Property14 { get; init; }` | The value of the fourteenth observed property. | None. | `T14` |
+| `Property15 { get; init; }` | The value of the fifteenth observed property. | None. | `T15` |
+| `Property16 { get; init; }` | The value of the sixteenth observed property. | None. | `T16` |
+| `Property2 { get; init; }` | The value of the second observed property. | None. | `T2` |
+| `Property3 { get; init; }` | The value of the third observed property. | None. | `T3` |
+| `Property4 { get; init; }` | The value of the fourth observed property. | None. | `T4` |
+| `Property5 { get; init; }` | The value of the fifth observed property. | None. | `T5` |
+| `Property6 { get; init; }` | The value of the sixth observed property. | None. | `T6` |
+| `Property7 { get; init; }` | The value of the seventh observed property. | None. | `T7` |
+| `Property8 { get; init; }` | The value of the eighth observed property. | None. | `T8` |
+| `Property9 { get; init; }` | The value of the ninth observed property. | None. | `T9` |
+
+## Bindings
+
+### One-way bindings
+
+[Full description and examples](bindings.md).
+
+Types: `ReactiveUI.Binding.ReactiveSchedulerExtensions`, `ReactiveUI.Binding.ReactiveUIBindingExtensions`.
+
+#### `ReactiveSchedulerExtensions`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class ReactiveSchedulerExtensions` | Binding extension methods that deliver writes on a caller-supplied scheduler. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BindOneWay<TSource, TTarget, TProperty>(TSource source, TTarget target, Expression<Func<TSource, TProperty>> sourceProperty, Expression<Func<TTarget, TProperty>> targetProperty, ISequencer? scheduler, string sourcePropertyExpression = "", string targetPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Creates a one-way binding from a source property to a target property with a specified scheduler. | `TSource : class`; `TTarget : class`: The type of the target object; `TProperty : notnull`: The type of the property being bound; `TSource` `source`; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; `ISequencer?` `scheduler`: The scheduler the write to the target is delivered on, in place of the target's owning thread; an immediate scheduler writes inline; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `sourcePropertyExpression`: The caller argument expression for `sourceProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `targetPropertyExpression`: The caller argument expression for `targetProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindOneWay<TSource, TSourceProp, TTarget, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, IBindingTypeConverter converter, object? conversionHint = null, ISequencer? scheduler = null, string callerFilePath = "", int callerLineNumber = 0)` | Creates a one-way binding from a source property to a target property using an explicit [`IBindingTypeConverter`](converters.md). | `TSource : class`; `TSourceProp : notnull`: The type of the source property; `TTarget : class`: The type of the target object; `TTargetProp : notnull`: The type of the target property; `TSource` `source`; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`IBindingTypeConverter`](converters.md) `converter`: The binding type converter to use for converting between source and target types; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An optional hint passed to the converter (e.g., format string); `ISequencer?` `scheduler`: The scheduler the write to the target is delivered on, in place of the target's owning thread; an immediate scheduler writes inline; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindOneWay<TSource, TSourceProp, TTarget, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, Func<TSourceProp, TTargetProp> conversionFunc, ISequencer? scheduler, string sourcePropertyExpression = "", string targetPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Creates a one-way binding from a source property to a target property with a conversion function and a specified scheduler. | `TSource : class`; `TSourceProp : notnull`: The type of the source property; `TTarget : class`: The type of the target object; `TTargetProp : notnull`: The type of the target property; `TSource` `source`; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`Func<TSourceProp, TTargetProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `conversionFunc`: A function that converts the source property value to the target property type; `ISequencer?` `scheduler`: The scheduler the write to the target is delivered on, in place of the target's owning thread; an immediate scheduler writes inline; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `sourcePropertyExpression`: The caller argument expression for `sourceProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `targetPropertyExpression`: The caller argument expression for `targetProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `OneWayBind<TView, TViewModel, TVMProp, TVProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, IBindingTypeConverter converter, object? conversionHint = null, ISequencer? scheduler = null, string callerFilePath = "", int callerLineNumber = 0)` | Creates a one-way binding from a view model property to a view property using an explicit [`IBindingTypeConverter`](converters.md). | `TView : class, IViewFor`; `TViewModel : class`: The type of the view model; `TVMProp : notnull`: The type of the view model property; `TVProp : notnull`: The type of the view property; `TView` `view`; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`IBindingTypeConverter`](converters.md) `converter`: The binding type converter to use for converting between source and target types; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An optional hint passed to the converter (e.g., format string); `ISequencer?` `scheduler`: The scheduler the write to the view is delivered on, in place of the view's owning thread; an immediate scheduler writes inline; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IReactiveBinding<TView, TVProp>`](bindings.md): A reactive binding that can be disposed to disconnect the binding. |
+| `OneWayBind<TView, TViewModel, TProp, TOut>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TProp>> viewModelProperty, Expression<Func<TView, TOut>> viewProperty, Func<TProp, TOut> selector, ISequencer? scheduler, string viewModelPropertyExpression = "", string viewPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Creates a one-way binding from a view model property to a view property with a specified selector and scheduler. | `TView : class, IViewFor`; `TViewModel : class`: The type of the view model; `TProp : notnull`: The type of the view model property; `TOut : notnull`: The type of the view property; `TView` `view`; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TOut>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`Func<TProp, TOut>`](https://learn.microsoft.com/dotnet/api/system.func-2) `selector`: A function that converts the view model property value to the view property type; `ISequencer?` `scheduler`: The scheduler the write to the view is delivered on, in place of the view's owning thread; an immediate scheduler writes inline; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `viewModelPropertyExpression`: The caller argument expression for `viewModelProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `viewPropertyExpression`: The caller argument expression for `viewProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IReactiveBinding<TView, TOut>`](bindings.md): A reactive binding that can be disposed to disconnect the binding. |
+
+#### `ReactiveUIBindingExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BindOneWay<TSource, TTarget, TProperty>(TSource source, TTarget target, Expression<Func<TSource, TProperty>> sourceProperty, Expression<Func<TTarget, TProperty>> targetProperty, string sourcePropertyExpression = "", string targetPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Binds a source property to a target property one way, writing the current value and each later change on the target's owning thread. | `TSource : class`: The type of the source object; `TTarget : class`: The type of the target object; `TProperty`: The type of the property being bound; `TSource` `source`: The source object to observe for property changes; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `sourcePropertyExpression`: The caller argument expression for `sourceProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `targetPropertyExpression`: The caller argument expression for `targetProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding; a binding hook that vetoes the binding leaves nothing bound. |
+| `BindOneWay<TSource, TSourceProp, TTarget, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, Func<TSourceProp, TTargetProp> conversionFunc, string sourcePropertyExpression = "", string targetPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Binds a source property to a target property one way through a conversion function, writing on the target's owning thread. | `TSource : class`: The type of the source object; `TSourceProp`: The type of the source property; `TTarget : class`: The type of the target object; `TTargetProp`: The type of the target property; `TSource` `source`: The source object to observe for property changes; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`Func<TSourceProp, TTargetProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `conversionFunc`: A function that converts the source property value to the target property type; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `sourcePropertyExpression`: The caller argument expression for `sourceProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `targetPropertyExpression`: The caller argument expression for `targetProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding; a binding hook that vetoes the binding leaves nothing bound. |
+| `OneWayBind<TViewModel, TView, TVMProp, TVProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, string viewModelPropertyExpression = "", string viewPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Binds a view model property to a view property one way, writing the current value and each later change on the view's owning thread. | `TViewModel : class`: The type of the view model; `TView : class, IViewFor`: The type of the view; `TVMProp`: The type of the view model property; `TVProp`: The type of the view property; `TView` `view`: The view to bind to; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `viewModelPropertyExpression`: The caller argument expression for `viewModelProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `viewPropertyExpression`: The caller argument expression for `viewProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IReactiveBinding<TView, TVProp>`](bindings.md): A reactive binding that can be disposed to disconnect the binding, or null when a binding hook vetoes it. |
+| `OneWayBind<TViewModel, TView, TProp, TOut>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TProp>> viewModelProperty, Expression<Func<TView, TOut>> viewProperty, Func<TProp, TOut> selector, string viewModelPropertyExpression = "", string viewPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Binds a view model property to a view property one way through a selector, writing on the view's owning thread. | `TViewModel : class`: The type of the view model; `TView : class, IViewFor`: The type of the view; `TProp`: The type of the view model property; `TOut`: The type of the view property; `TView` `view`: The view to bind to; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TOut>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`Func<TProp, TOut>`](https://learn.microsoft.com/dotnet/api/system.func-2) `selector`: A function that converts the view model property value to the view property type; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `viewModelPropertyExpression`: The caller argument expression for `viewModelProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `viewPropertyExpression`: The caller argument expression for `viewProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IReactiveBinding<TView, TOut>`](bindings.md): A reactive binding that can be disposed to disconnect the binding, or null when a binding hook vetoes it. |
+
+### Two-way bindings
+
+[Full description and examples](bindings.md).
+
+Types: `ReactiveUI.Binding.ReactiveSchedulerExtensions`, `ReactiveUI.Binding.ReactiveUIBindingExtensions`.
+
+#### `ReactiveSchedulerExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Bind<TView, TViewModel, TVMProp, TVProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, IBindingTypeConverter viewModelToViewConverter, IBindingTypeConverter viewToViewModelConverter, object? conversionHint = null, ISequencer? scheduler = null, string callerFilePath = "", int callerLineNumber = 0)` | Creates a two-way binding between a view model property and a view property using explicit [`IBindingTypeConverter`](converters.md) instances. | `TView : class, IViewFor`; `TViewModel : class`: The type of the view model; `TVMProp : notnull`: The type of the view model property; `TVProp : notnull`: The type of the view property; `TView` `view`; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`IBindingTypeConverter`](converters.md) `viewModelToViewConverter`: The converter for view model-to-view conversion; [`IBindingTypeConverter`](converters.md) `viewToViewModelConverter`: The converter for view-to-view model conversion; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An optional hint passed to the converters (e.g., format string); `ISequencer?` `scheduler`: The scheduler each write is delivered on, in place of the view's owning thread; an immediate scheduler writes inline; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IReactiveBinding<TView, BindingChange>`](bindings.md): A reactive binding that can be disposed to disconnect the binding. |
+| `Bind<TView, TViewModel, TVMProp, TVProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, Func<TVMProp, TVProp> viewModelToViewConverter, Func<TVProp, TVMProp> viewToViewModelConverter, ISequencer? scheduler, string viewModelPropertyExpression = "", string viewPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Creates a two-way binding between a view model property and a view property with conversion functions and a specified scheduler. | `TView : class, IViewFor`; `TViewModel : class`: The type of the view model; `TVMProp : notnull`: The type of the view model property; `TVProp : notnull`: The type of the view property; `TView` `view`; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`Func<TVMProp, TVProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `viewModelToViewConverter`: A function that converts the view model property value to the view property type; [`Func<TVProp, TVMProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `viewToViewModelConverter`: A function that converts the view property value back to the view model property type; `ISequencer?` `scheduler`: The scheduler each write is delivered on, in place of the view's owning thread; an immediate scheduler writes inline; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `viewModelPropertyExpression`: The caller argument expression for `viewModelProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `viewPropertyExpression`: The caller argument expression for `viewProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IReactiveBinding<TView, BindingChange>`](bindings.md): A reactive binding that can be disposed to disconnect the binding. |
+| `BindTwoWay<TSource, TTarget, TProperty>(TSource source, TTarget target, Expression<Func<TSource, TProperty>> sourceProperty, Expression<Func<TTarget, TProperty>> targetProperty, ISequencer? scheduler, string sourcePropertyExpression = "", string targetPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Creates a two-way binding between a source property and a target property with a specified scheduler. | `TSource : class`; `TTarget : class`: The type of the target object; `TProperty : notnull`: The type of the property being bound; `TSource` `source`; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; `ISequencer?` `scheduler`: The scheduler each write is delivered on, in place of the target's owning thread; an immediate scheduler writes inline; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `sourcePropertyExpression`: The caller argument expression for `sourceProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `targetPropertyExpression`: The caller argument expression for `targetProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindTwoWay<TSource, TSourceProp, TTarget, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, IBindingTypeConverter sourceToTargetConverter, IBindingTypeConverter targetToSourceConverter, object? conversionHint = null, ISequencer? scheduler = null, string callerFilePath = "", int callerLineNumber = 0)` | Creates a two-way binding between a source property and a target property using explicit [`IBindingTypeConverter`](converters.md) instances. | `TSource : class`; `TSourceProp : notnull`: The type of the source property; `TTarget : class`: The type of the target object; `TTargetProp : notnull`: The type of the target property; `TSource` `source`; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`IBindingTypeConverter`](converters.md) `sourceToTargetConverter`: The converter for source-to-target conversion; [`IBindingTypeConverter`](converters.md) `targetToSourceConverter`: The converter for target-to-source conversion; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An optional hint passed to the converters (e.g., format string); `ISequencer?` `scheduler`: The scheduler each write is delivered on, in place of the target's owning thread; an immediate scheduler writes inline; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindTwoWay<TSource, TSourceProp, TTarget, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, Func<TSourceProp, TTargetProp> sourceToTargetConv, Func<TTargetProp, TSourceProp> targetToSourceConv, ISequencer? scheduler, string sourcePropertyExpression = "", string targetPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Creates a two-way binding between a source property and a target property with conversion functions and a specified scheduler. | `TSource : class`; `TSourceProp : notnull`: The type of the source property; `TTarget : class`: The type of the target object; `TTargetProp : notnull`: The type of the target property; `TSource` `source`; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`Func<TSourceProp, TTargetProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `sourceToTargetConv`: A function that converts the source property value to the target property type; [`Func<TTargetProp, TSourceProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `targetToSourceConv`: A function that converts the target property value back to the source property type; `ISequencer?` `scheduler`: The scheduler each write is delivered on, in place of the target's owning thread; an immediate scheduler writes inline; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `sourcePropertyExpression`: The caller argument expression for `sourceProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `targetPropertyExpression`: The caller argument expression for `targetProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+
+#### `ReactiveUIBindingExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Bind<TViewModel, TView, TVMProp, TVProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, string viewModelPropertyExpression = "", string viewPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Binds a view model property and a view property to each other, seeding the view and mirroring each change on the other side's owning thread. | `TViewModel : class`: The type of the view model; `TView : class, IViewFor`: The type of the view; `TVMProp`: The type of the view model property; `TVProp`: The type of the view property; `TView` `view`: The view to bind to; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `viewModelPropertyExpression`: The caller argument expression for `viewModelProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `viewPropertyExpression`: The caller argument expression for `viewProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IReactiveBinding<TView, BindingChange>`](bindings.md): A reactive binding that can be disposed to disconnect the binding, or null when a binding hook vetoes it. |
+| `Bind<TViewModel, TView, TVMProp, TVProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, Func<TVMProp, TVProp> viewModelToViewConverter, Func<TVProp, TVMProp> viewToViewModelConverter, string viewModelPropertyExpression = "", string viewPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Binds a view model property and a view property to each other through conversion functions, seeding the view and mirroring each change on the other side's owning thread. | `TViewModel : class`: The type of the view model; `TView : class, IViewFor`: The type of the view; `TVMProp`: The type of the view model property; `TVProp`: The type of the view property; `TView` `view`: The view to bind to; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`Func<TVMProp, TVProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `viewModelToViewConverter`: A function that converts the view model property value to the view property type; [`Func<TVProp, TVMProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `viewToViewModelConverter`: A function that converts the view property value back to the view model property type; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `viewModelPropertyExpression`: The caller argument expression for `viewModelProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `viewPropertyExpression`: The caller argument expression for `viewProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IReactiveBinding<TView, BindingChange>`](bindings.md): A reactive binding that can be disposed to disconnect the binding, or null when a binding hook vetoes it. |
+| `BindTwoWay<TSource, TTarget, TProperty>(TSource source, TTarget target, Expression<Func<TSource, TProperty>> sourceProperty, Expression<Func<TTarget, TProperty>> targetProperty, string sourcePropertyExpression = "", string targetPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Binds a source and a target property to each other, seeding the target from the source and mirroring each change on the other side's owning thread. | `TSource : class`: The type of the source object; `TTarget : class`: The type of the target object; `TProperty`: The type of the property being bound; `TSource` `source`: The source object to observe for property changes; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `sourcePropertyExpression`: The caller argument expression for `sourceProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `targetPropertyExpression`: The caller argument expression for `targetProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding; a binding hook that vetoes the binding leaves nothing bound. |
+| `BindTwoWay<TSource, TSourceProp, TTarget, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, Func<TSourceProp, TTargetProp> sourceToTargetConv, Func<TTargetProp, TSourceProp> targetToSourceConv, string sourcePropertyExpression = "", string targetPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Binds a source and a target property to each other through conversion functions, seeding the target and mirroring each change on the other side's owning thread. | `TSource : class`: The type of the source object; `TSourceProp`: The type of the source property; `TTarget : class`: The type of the target object; `TTargetProp`: The type of the target property; `TSource` `source`: The source object to observe for property changes; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`Func<TSourceProp, TTargetProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `sourceToTargetConv`: A function that converts the source property value to the target property type; [`Func<TTargetProp, TSourceProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `targetToSourceConv`: A function that converts the target property value back to the source property type; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `sourcePropertyExpression`: The caller argument expression for `sourceProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `targetPropertyExpression`: The caller argument expression for `targetProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding; a binding hook that vetoes the binding leaves nothing bound. |
+
+### BindTo
+
+[Full description and examples](bindings.md).
+
+Types: `ReactiveUI.Binding.ReactiveUIBindingExtensions`.
+
+#### `ReactiveUIBindingExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `IObservable<TValue>.BindTo<TValue, TTarget, TTargetValue>(TTarget? target, Expression<Func<TTarget, TTargetValue?>> property, string propertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Writes each value the source produces to a target property, on the target's owning thread when its platform has one. | `TValue`: The type of the value produced by the source observable; `TTarget : class`: The type of the target object; `TTargetValue`: The type of the property on the target object; [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source` (receiver): The observable stream to bind to a target property; `TTarget?` `target`: The target object whose property will be set; [`Expression<Func<TTarget, TTargetValue?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: An expression that selects the target property to set; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyExpression`: The caller argument expression for `property`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `IObservable<TValue>.BindTo<TValue, TTarget, TTargetValue>(TTarget? target, Expression<Func<TTarget, TTargetValue?>> property, IBindingTypeConverter? converterOverride, string propertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Writes each value the source produces to a target property, coercing it with the supplied converter instead of a registered one. | `TValue`: The type of the value produced by the source observable; `TTarget : class`: The type of the target object; `TTargetValue`: The type of the property on the target object; [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source` (receiver): The observable stream to bind to a target property; `TTarget?` `target`: The target object whose property will be set; [`Expression<Func<TTarget, TTargetValue?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: An expression that selects the target property to set; [`IBindingTypeConverter?`](converters.md) `converterOverride`: An explicit converter to use when converting the source value to the target property type; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyExpression`: The caller argument expression for `property`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `IObservable<TValue>.BindTo<TValue, TTarget, TTargetValue>(TTarget? target, Expression<Func<TTarget, TTargetValue?>> property, object? conversionHint, string propertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Writes each value the source produces to a target property, passing the conversion hint to the converter that coerces the value to the property type. | `TValue`: The type of the value produced by the source observable; `TTarget : class`: The type of the target object; `TTargetValue`: The type of the property on the target object; [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source` (receiver): The observable stream to bind to a target property; `TTarget?` `target`: The target object whose property will be set; [`Expression<Func<TTarget, TTargetValue?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: An expression that selects the target property to set; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An object that provides a hint to the converter. The semantics are defined by the converter; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyExpression`: The caller argument expression for `property`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `IObservable<TValue>.BindTo<TValue, TTarget, TTargetValue>(TTarget? target, Expression<Func<TTarget, TTargetValue?>> property, object? conversionHint, IBindingTypeConverter? converterOverride, string propertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Writes each value the source produces to a target property, coercing it with the supplied converter instead of a registered one and passing the conversion hint to it. | `TValue`: The type of the value produced by the source observable; `TTarget : class`: The type of the target object; `TTargetValue`: The type of the property on the target object; [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source` (receiver): The observable stream to bind to a target property; `TTarget?` `target`: The target object whose property will be set; [`Expression<Func<TTarget, TTargetValue?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: An expression that selects the target property to set; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An object that provides a hint to the converter. The semantics are defined by the converter; [`IBindingTypeConverter?`](converters.md) `converterOverride`: An explicit converter to use when converting the source value to the target property type; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyExpression`: The caller argument expression for `property`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+
+### Command bindings
+
+[Full description and examples](bindings.md).
+
+Types: `ReactiveUI.Binding.ReactiveUIBindingExtensions`.
+
+#### `ReactiveUIBindingExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BindCommand<TView, TViewModel, TProp, TControl>(TView view, TViewModel? viewModel, Expression<Func<TViewModel, TProp?>> propertyName, Expression<Func<TView, TControl>> controlName, string? toEvent = null, string propertyNameExpression = "", string controlNameExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Binds the command a view model property holds to the control a view property holds, rebinding when either changes. | `TView : class, IViewFor`: The type of the view; `TViewModel : class`: The type of the view model; `TProp : ICommand`: The type of the command property; `TControl : class`: The type of the control; `TView` `view`: The view to bind to; `TViewModel?` `viewModel`: The view model containing the command; null binds nothing; [`Expression<Func<TViewModel, TProp?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `propertyName`: An expression that selects the command property on the view model; [`Expression<Func<TView, TControl>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `controlName`: An expression that selects the control on the view; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `toEvent`: The event name to bind to. If null, a default event is selected; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyNameExpression`: The caller argument expression for `propertyName`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `controlNameExpression`: The caller argument expression for `controlName`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindCommand<TView, TViewModel, TProp, TControl, TParam>(TView view, TViewModel? viewModel, Expression<Func<TViewModel, TProp?>> propertyName, Expression<Func<TView, TControl>> controlName, IObservable<TParam?> withParameter, string? toEvent = null, string propertyNameExpression = "", string controlNameExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Binds the command a view model property holds to the control a view property holds, using an observable as the source of the command parameter. | `TView : class, IViewFor`: The type of the view; `TViewModel : class`: The type of the view model; `TProp : ICommand`: The type of the command property; `TControl : class`: The type of the control; `TParam`: The type of the command parameter; `TView` `view`: The view to bind to; `TViewModel?` `viewModel`: The view model containing the command; null binds nothing; [`Expression<Func<TViewModel, TProp?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `propertyName`: An expression that selects the command property on the view model; [`Expression<Func<TView, TControl>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `controlName`: An expression that selects the control on the view; [`IObservable<TParam?>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `withParameter`: An observable that provides the command parameter; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `toEvent`: The event name to bind to. If null, a default event is selected; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyNameExpression`: The caller argument expression for `propertyName`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `controlNameExpression`: The caller argument expression for `controlName`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindCommand<TView, TViewModel, TProp, TControl, TParam>(TView view, TViewModel? viewModel, Expression<Func<TViewModel, TProp?>> propertyName, Expression<Func<TView, TControl>> controlName, Expression<Func<TViewModel, TParam?>> withParameter, string? toEvent = null, string propertyNameExpression = "", string controlNameExpression = "", string withParameterExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Binds the command a view model property holds to the control a view property holds, using a view model property as the command parameter. | `TView : class, IViewFor`: The type of the view; `TViewModel : class`: The type of the view model; `TProp : ICommand`: The type of the command property; `TControl : class`: The type of the control; `TParam`: The type of the command parameter; `TView` `view`: The view to bind to; `TViewModel?` `viewModel`: The view model containing the command; null binds nothing; [`Expression<Func<TViewModel, TProp?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `propertyName`: An expression that selects the command property on the view model; [`Expression<Func<TView, TControl>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `controlName`: An expression that selects the control on the view; [`Expression<Func<TViewModel, TParam?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `withParameter`: An expression that selects the command parameter property on the view model; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `toEvent`: The event name to bind to. If null, a default event is selected; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyNameExpression`: The caller argument expression for `propertyName`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `controlNameExpression`: The caller argument expression for `controlName`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `withParameterExpression`: The caller argument expression for `withParameter`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+
+### Invoke a command from a stream
+
+[Full description and examples](bindings.md).
+
+Types: `ReactiveUI.Binding.ReactiveUIBindingExtensions`.
+
+#### `ReactiveUIBindingExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `IObservable<T>.InvokeCommand<T>(ICommand command)` | Executes a command with each value the sequence produces as its parameter, skipping a value the command cannot execute. | `T`: The type of the value offered as the command parameter; [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source` (receiver): The sequence driving the executions; [`ICommand`](https://learn.microsoft.com/dotnet/api/system.windows.input.icommand) `command`: The command to execute | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, stops executing the command. |
+| `IObservable<T>.InvokeCommand<T, TTarget>(TTarget? target, Expression<Func<TTarget, ICommand?>> commandProperty, string commandPropertyExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Executes the command a property holds with each value as its parameter, skipping a value while there is no command or the command cannot execute it. | `T`: The type of the value offered as the command parameter; `TTarget : class`: The type declaring the command property; [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source` (receiver): The sequence driving the executions; `TTarget?` `target`: The object declaring the command property; null executes nothing; [`Expression<Func<TTarget, ICommand?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `commandProperty`: An expression that selects the command property to execute; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `commandPropertyExpression`: The caller argument expression for `commandProperty`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, stops executing the command and stops observing the property. |
+
+### Interactions
+
+[Full description and examples](bindings.md).
+
+Types: `ReactiveUI.Binding.IInteraction<TInput, TOutput>`, `ReactiveUI.Binding.IInteractionContext<TInput, TOutput>`, `ReactiveUI.Binding.IOutputContext<TInput, TOutput>`, `ReactiveUI.Binding.Interaction<TInput, TOutput>`, `ReactiveUI.Binding.InteractionContext<TInput, TOutput>`, `ReactiveUI.Binding.ReactiveUIBindingExtensions`, `ReactiveUI.Binding.UnhandledInteractionException<TInput, TOutput>`.
+
+#### `IInteraction<TInput, TOutput>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IInteraction<TInput, TOutput>` | Represents an interaction between collaborating application components. | `TInput`: The interaction's input type; `TOutput`: The interaction's output type | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Handle(TInput input)` | Handles an interaction and asynchronously returns the result. | `TInput` `input`: The input for the interaction | [`Task<TOutput>`](https://learn.microsoft.com/dotnet/api/system.threading.tasks.task-1): A task that completes with the output when the interaction is handled. |
+| `RegisterHandler(Action<IInteractionContext<TInput, TOutput>> handler)` | Registers a synchronous interaction handler. | [`Action<IInteractionContext<TInput, TOutput>>`](https://learn.microsoft.com/dotnet/api/system.action-1) `handler`: The handler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable which, when disposed, will unregister the handler. |
+| `RegisterHandler(Func<IInteractionContext<TInput, TOutput>, Task> handler)` | Registers a task-based asynchronous interaction handler. | [`Func<IInteractionContext<TInput, TOutput>, Task>`](https://learn.microsoft.com/dotnet/api/system.func-2) `handler`: The handler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable which, when disposed, will unregister the handler. |
+| `RegisterHandler<TDontCare>(Func<IInteractionContext<TInput, TOutput>, IObservable<TDontCare>> handler)` | Registers an observable-based asynchronous interaction handler. | `TDontCare`: The signal type; [`Func<IInteractionContext<TInput, TOutput>, IObservable<TDontCare>>`](https://learn.microsoft.com/dotnet/api/system.func-2) `handler`: The handler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable which, when disposed, will unregister the handler. |
+
+#### `IInteractionContext<TInput, TOutput>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IInteractionContext<TInput, TOutput>` | Contains contextual information for an interaction. | `TInput`: The type of the interaction's input; `TOutput`: The type of the interaction's output | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `SetOutput(TOutput output)` | Sets the output for the interaction. | `TOutput` `output`: The output | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Input { get; }` | Gets the input for the interaction. | None. | `TInput` |
+| `IsHandled { get; }` | Gets a value indicating whether the interaction is handled. That is, whether the output has been set. | None. | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) |
+
+#### `IOutputContext<TInput, TOutput>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IOutputContext<TInput, TOutput>` | Extends [`IInteractionContext<TInput, TOutput>`](bindings.md) with the ability to retrieve the output. | `TInput`: The type of the interaction's input; `TOutput`: The type of the interaction's output | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetOutput()` | Gets the output of the interaction. | None. | `TOutput`: The output. |
+
+#### `Interaction<TInput, TOutput>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `class Interaction<TInput, TOutput>` | Represents an interaction between collaborating application components. | `TInput`: The interaction's input type; `TOutput`: The interaction's output type | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Interaction()` | Initializes a new instance of the Interaction<TInput, TOutput> class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `protected virtual GenerateContext(TInput input)` | Creates the context every handler receives for one call to `Handle`. | `TInput` `input`: The input passed to `Handle` | [`IOutputContext<TInput, TOutput>`](bindings.md): A new interaction context carrying the input. |
+| `protected GetHandlers()` | Gets a copy of the registered handlers in order of registration. | None. | [`Func<IInteractionContext<TInput, TOutput>, Task>[]`](https://learn.microsoft.com/dotnet/api/system.func-2): The registered handlers, earliest first. |
+| `virtual Handle(TInput input)` | Runs the handlers, latest registered first, until one sets an output, and returns that output. | `TInput` `input`: The input for the interaction | [`Task<TOutput>`](https://learn.microsoft.com/dotnet/api/system.threading.tasks.task-1): A task that completes with the output the first handling handler set. |
+| `RegisterHandler(Action<IInteractionContext<TInput, TOutput>> handler)` | Registers a synchronous interaction handler. | [`Action<IInteractionContext<TInput, TOutput>>`](https://learn.microsoft.com/dotnet/api/system.action-1) `handler`: The handler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable which, when disposed, will unregister the handler. |
+| `RegisterHandler(Func<IInteractionContext<TInput, TOutput>, Task> handler)` | Registers a task-based asynchronous interaction handler. | [`Func<IInteractionContext<TInput, TOutput>, Task>`](https://learn.microsoft.com/dotnet/api/system.func-2) `handler`: The handler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable which, when disposed, will unregister the handler. |
+| `RegisterHandler<TDontCare>(Func<IInteractionContext<TInput, TOutput>, IObservable<TDontCare>> handler)` | Registers a handler that finishes when the observable it returns completes. | `TDontCare`: The element type of the returned observable; the values are ignored; [`Func<IInteractionContext<TInput, TOutput>, IObservable<TDontCare>>`](https://learn.microsoft.com/dotnet/api/system.func-2) `handler`: The handler; the interaction moves to the next handler once the observable completes, and a fault in the observable faults `Handle` | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable which, when disposed, unregisters the handler. |
+
+#### `InteractionContext<TInput, TOutput>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class InteractionContext<TInput, TOutput>` | Contains contextual information for an interaction. | `TInput`: The type of the interaction's input; `TOutput`: The type of the interaction's output | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetOutput()` | Gets the output of the interaction. | None. | `TOutput`: The output. |
+| `SetOutput(TOutput output)` | Sets the output for the interaction and marks it handled. | `TOutput` `output`: The output | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Input { get; }` | Gets the input for the interaction. | None. | `TInput` |
+| `IsHandled { get; }` | Gets a value indicating whether the interaction is handled. That is, whether the output has been set. | None. | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) |
+
+#### `ReactiveUIBindingExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BindInteraction<TViewModel, TView, TInput, TOutput>(TView view, TViewModel? viewModel, Expression<Func<TViewModel, IInteraction<TInput, TOutput>>> propertyName, Func<IInteractionContext<TInput, TOutput>, Task> handler, string propertyNameExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Registers a task-based handler on the interaction a view model property holds, moving it to the new interaction when the property changes. | `TViewModel : class`: The type of the view model; `TView : class, IViewFor`: The type of the view; `TInput`: The type of the interaction's input; `TOutput`: The type of the interaction's output; `TView` `view`: The view that provides the handler; `TViewModel?` `viewModel`: The view model that exposes the interaction; null registers nothing; [`Expression<Func<TViewModel, IInteraction<TInput, TOutput>>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `propertyName`: An expression that selects the interaction property on the view model; [`Func<IInteractionContext<TInput, TOutput>, Task>`](https://learn.microsoft.com/dotnet/api/system.func-2) `handler`: A task-based handler for the interaction; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyNameExpression`: The caller argument expression for `propertyName`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, unregisters the handler and stops observing the property. |
+| `BindInteraction<TViewModel, TView, TInput, TOutput, TDontCare>(TView view, TViewModel? viewModel, Expression<Func<TViewModel, IInteraction<TInput, TOutput>>> propertyName, Func<IInteractionContext<TInput, TOutput>, IObservable<TDontCare>> handler, string propertyNameExpression = "", string callerFilePath = "", int callerLineNumber = 0)` | Registers an observable-based handler on the interaction a view model property holds, moving it to the new interaction when the property changes. | `TViewModel : class`: The type of the view model; `TView : class, IViewFor`: The type of the view; `TInput`: The type of the interaction's input; `TOutput`: The type of the interaction's output; `TDontCare`: The signal type of the observable handler; `TView` `view`: The view that provides the handler; `TViewModel?` `viewModel`: The view model that exposes the interaction; null registers nothing; [`Expression<Func<TViewModel, IInteraction<TInput, TOutput>>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `propertyName`: An expression that selects the interaction property on the view model; [`Func<IInteractionContext<TInput, TOutput>, IObservable<TDontCare>>`](https://learn.microsoft.com/dotnet/api/system.func-2) `handler`: An observable-based handler for the interaction; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyNameExpression`: The caller argument expression for `propertyName`. Auto-populated by the compiler; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `callerFilePath`: The source file path of the caller. Auto-populated by the compiler; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `callerLineNumber`: The source line number of the caller. Auto-populated by the compiler | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, unregisters the handler and stops observing the property. |
+
+#### `UnhandledInteractionException<TInput, TOutput>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `class UnhandledInteractionException<TInput, TOutput> : Exception` | Indicates that an interaction has gone unhandled. | `TInput`: The type of the interaction's input; `TOutput`: The type of the interaction's output | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `UnhandledInteractionException()` | Initializes a new instance of the [`UnhandledInteractionException<TInput, TOutput>`](bindings.md) class. | None. | — |
+| `UnhandledInteractionException(string message)` | Initializes a new instance of the [`UnhandledInteractionException<TInput, TOutput>`](bindings.md) class. | [`string`](https://learn.microsoft.com/dotnet/api/system.string) `message`: A message about the exception | — |
+| `UnhandledInteractionException(Interaction<TInput, TOutput> interaction, TInput input)` | Initializes a new instance of the [`UnhandledInteractionException<TInput, TOutput>`](bindings.md) class for an interaction no handler handled. | [`Interaction<TInput, TOutput>`](bindings.md) `interaction`: The interaction that no handler handled; `TInput` `input`: The input into the interaction | — |
+| `UnhandledInteractionException(string message, Exception innerException)` | Initializes a new instance of the [`UnhandledInteractionException<TInput, TOutput>`](bindings.md) class. | [`string`](https://learn.microsoft.com/dotnet/api/system.string) `message`: A message about the exception; [`Exception`](https://learn.microsoft.com/dotnet/api/system.exception) `innerException`: Any other exception that caused the issue | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Input { get; }` | Gets the input for the interaction that was not handled, or the default value when the exception was created without one. | None. | `TInput` |
+| `Interaction { get; }` | Gets the interaction that was not handled, or null when the exception was created without one. | None. | [`Interaction<TInput, TOutput>?`](bindings.md) |
+
+### Reactive bindings
+
+[Full description and examples](bindings.md).
+
+Types: `ReactiveUI.Binding.BindingChange`, `ReactiveUI.Binding.BindingDirection`, `ReactiveUI.Binding.IReactiveBinding<TView, TValue>`, `ReactiveUI.Binding.ReactiveBinding<TView, TValue>`.
+
+#### `BindingChange`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `readonly struct BindingChange` | A value a two-way binding moved, and which side of the binding produced it. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BindingChange(object? Value, bool FromViewModel)` | A value a two-way binding moved, and which side of the binding produced it. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `Value`: The value that was written; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `FromViewModel`: Whether the view model produced the value, rather than the view | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromViewModel { get; init; }` | Whether the view model produced the value, rather than the view. | None. | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) |
+| `Value { get; init; }` | The value that was written. | None. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) |
+
+#### `BindingDirection`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `enum BindingDirection` | Specifies the direction of a property binding. | None. | — |
+
+**Enum values**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `OneWay = 0` | One-way binding from source to target. | None. | — |
+| `TwoWay = 1` | Two-way binding between source and target. | None. | — |
+| `AsyncOneWay = 2` | One-way asynchronous binding from source to target. | None. | — |
+
+#### `IReactiveBinding<TView, TValue>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IReactiveBinding<TView, TValue>` | Represents a binding between a view and a view model property. | `TView : IViewFor`: The type of the view; `TValue`: The type of the bound value | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Changed { get; }` | Gets an observable that signals when the binding value changes. | None. | [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) |
+| `Direction { get; }` | Gets the direction of the binding. | None. | [`BindingDirection`](bindings.md) |
+| `View { get; }` | Gets the view that is bound. | None. | `TView` |
+| `ViewExpression { get; }` | Gets the expression representing the view property that is bound, or null when the binding carries none. | None. | [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) |
+| `ViewModelExpression { get; }` | Gets the expression representing the view model property that is bound, or null when the binding carries none. | None. | [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) |
+
+#### `ReactiveBinding<TView, TValue>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ReactiveBinding<TView, TValue>` | Default implementation of [`IReactiveBinding<TView, TValue>`](bindings.md) used by generated view-first bindings. | `TView : IViewFor`: The type of the view; `TValue`: The type of the bound value | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ReactiveBinding(TView view, IObservable<TValue> changed, BindingDirection direction, IDisposable subscription)` | Initializes a new instance of the [`ReactiveBinding<TView, TValue>`](bindings.md) class. | `TView` `view`: The view that is bound; [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `changed`: An observable that signals when the binding value changes; [`BindingDirection`](bindings.md) `direction`: The direction of the binding; [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable) `subscription`: The underlying subscription to dispose when the binding is disposed | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Dispose()` | Disposes the underlying subscription on the first call; later calls do nothing. | None. | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Changed { get; }` | Gets an observable that signals when the binding value changes. | None. | [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) |
+| `Direction { get; }` | Gets the direction of the binding. | None. | [`BindingDirection`](bindings.md) |
+| `View { get; }` | Gets the view that is bound. | None. | `TView` |
+| `ViewExpression { get; }` | Gets the view expression, which is always null because a generated binding carries no expression. | None. | [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) |
+| `ViewModelExpression { get; }` | Gets the view model expression, which is always null because a generated binding carries no expression. | None. | [`Expression?`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) |
+
+### Binding hooks
+
+[Full description and examples](bindings.md).
+
+Types: `ReactiveUI.Binding.BindingHooks`, `ReactiveUI.Binding.IPropertyBindingHook`.
+
+#### `BindingHooks`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class BindingHooks` | Lets a registered [`IPropertyBindingHook`](bindings.md) inspect, or refuse, a binding as it is created. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Refresh()` | Discards the cached hooks so the next use reads them from the service locator again. | None. | — |
+| `ShouldBind(object? source, object target, Func<IObservedChange<object, object>[]> getSourceProperties, Func<IObservedChange<object, object>[]> getTargetProperties, BindingDirection direction)` | Asks the registered hooks in turn whether this binding may be created, stopping at the first refusal. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `source`: The source object, typically the view model; may be null; [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: The target object, typically the view; [`Func<IObservedChange<object, object>[]>`](https://learn.microsoft.com/dotnet/api/system.func-1) `getSourceProperties`: Reads the current source-side values; [`Func<IObservedChange<object, object>[]>`](https://learn.microsoft.com/dotnet/api/system.func-1) `getTargetProperties`: Reads the current target-side values; [`BindingDirection`](bindings.md) `direction`: Which way the binding runs | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` when the binding may proceed, including when no hook is registered; `false` when a hook refused it. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Any { get; }` | Gets a value indicating whether any hook was registered when the hooks were last read. | None. | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) |
+
+#### `IPropertyBindingHook`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IPropertyBindingHook` | Implement this as a way to intercept bindings at the time that they are created and execute an additional action (or to cancel the binding). | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ExecuteHook(object? source, object target, Func<IObservedChange<object, object>[]> getCurrentViewModelProperties, Func<IObservedChange<object, object>[]> getCurrentViewProperties, BindingDirection direction)` | Called as a binding is set up, before it is wired, and can refuse the binding. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `source`: The source ViewModel; may be null; [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: The target View (not the actual control); [`Func<IObservedChange<object, object>[]>`](https://learn.microsoft.com/dotnet/api/system.func-1) `getCurrentViewModelProperties`: Reads the current values along the view model property path when called; [`Func<IObservedChange<object, object>[]>`](https://learn.microsoft.com/dotnet/api/system.func-1) `getCurrentViewProperties`: Reads the current values along the view property path when called; [`BindingDirection`](bindings.md) `direction`: The Binding direction | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` to let the binding proceed; `false` to cancel it. |
+
+### Binding errors
+
+[Full description and examples](bindings.md).
+
+Types: `ReactiveUI.Binding.BindingErrors`.
+
+#### `BindingErrors`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class BindingErrors` | How a binding reacts when the sequence feeding its write faults. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Subscribe<T>(IObservable<T> source, Action<T> onNext, string bindingExpression)` | Subscribes a binding's write to its source, applying the binding fault contract. | `T`: The type of the value written; [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source`: The sequence feeding the write; [`Action<T>`](https://learn.microsoft.com/dotnet/api/system.action-1) `onNext`: The write itself; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `bindingExpression`: The bound expression, named in the log entry and the rethrown exception | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the write. |
+
+## Converters
+
+### Numbers
+
+[Full description and examples](converters.md).
+
+Types: `ReactiveUI.Binding.ByteToStringTypeConverter`, `ReactiveUI.Binding.DecimalToStringTypeConverter`, `ReactiveUI.Binding.DoubleToStringTypeConverter`, `ReactiveUI.Binding.IntegerToStringTypeConverter`, `ReactiveUI.Binding.LongToStringTypeConverter`, `ReactiveUI.Binding.ShortToStringTypeConverter`, `ReactiveUI.Binding.SingleToStringTypeConverter`, `ReactiveUI.Binding.StringToByteTypeConverter`, `ReactiveUI.Binding.StringToDecimalTypeConverter`, `ReactiveUI.Binding.StringToDoubleTypeConverter`, `ReactiveUI.Binding.StringToIntegerTypeConverter`, `ReactiveUI.Binding.StringToLongTypeConverter`, `ReactiveUI.Binding.StringToShortTypeConverter`, `ReactiveUI.Binding.StringToSingleTypeConverter`.
+
+#### `ByteToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ByteToStringTypeConverter : BindingTypeConverter<byte, string>` | Converts a [`byte`](https://learn.microsoft.com/dotnet/api/system.byte) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the minimum digit count (the `D` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ByteToStringTypeConverter()` | Initializes a new instance of the ByteToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(byte from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`byte`](https://learn.microsoft.com/dotnet/api/system.byte) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `DecimalToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class DecimalToStringTypeConverter : BindingTypeConverter<decimal, string>` | Converts a [`decimal`](https://learn.microsoft.com/dotnet/api/system.decimal) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the number of decimal places (the `F` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `DecimalToStringTypeConverter()` | Initializes a new instance of the DecimalToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(decimal from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`decimal`](https://learn.microsoft.com/dotnet/api/system.decimal) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `DoubleToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class DoubleToStringTypeConverter : BindingTypeConverter<double, string>` | Converts a [`double`](https://learn.microsoft.com/dotnet/api/system.double) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the number of decimal places (the `F` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `DoubleToStringTypeConverter()` | Initializes a new instance of the DoubleToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(double from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`double`](https://learn.microsoft.com/dotnet/api/system.double) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `IntegerToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class IntegerToStringTypeConverter : BindingTypeConverter<int, string>` | Converts an [`int`](https://learn.microsoft.com/dotnet/api/system.int32) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the minimum digit count (the `D` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `IntegerToStringTypeConverter()` | Initializes a new instance of the IntegerToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(int from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `LongToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class LongToStringTypeConverter : BindingTypeConverter<long, string>` | Converts a [`long`](https://learn.microsoft.com/dotnet/api/system.int64) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the minimum digit count (the `D` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `LongToStringTypeConverter()` | Initializes a new instance of the LongToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(long from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`long`](https://learn.microsoft.com/dotnet/api/system.int64) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `ShortToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ShortToStringTypeConverter : BindingTypeConverter<short, string>` | Converts a [`short`](https://learn.microsoft.com/dotnet/api/system.int16) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the minimum digit count (the `D` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ShortToStringTypeConverter()` | Initializes a new instance of the ShortToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(short from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`short`](https://learn.microsoft.com/dotnet/api/system.int16) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `SingleToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class SingleToStringTypeConverter : BindingTypeConverter<float, string>` | Converts a [`float`](https://learn.microsoft.com/dotnet/api/system.single) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the number of decimal places (the `F` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `SingleToStringTypeConverter()` | Initializes a new instance of the SingleToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(float from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`float`](https://learn.microsoft.com/dotnet/api/system.single) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToByteTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToByteTypeConverter : BindingTypeConverter<string, byte>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`byte`](https://learn.microsoft.com/dotnet/api/system.byte) with `TryParse` under the current culture; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToByteTypeConverter()` | Initializes a new instance of the StringToByteTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out byte result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`byte`](https://learn.microsoft.com/dotnet/api/system.byte) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToDecimalTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToDecimalTypeConverter : BindingTypeConverter<string, decimal>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`decimal`](https://learn.microsoft.com/dotnet/api/system.decimal) with `TryParse` under the current culture; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToDecimalTypeConverter()` | Initializes a new instance of the StringToDecimalTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out decimal result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`decimal`](https://learn.microsoft.com/dotnet/api/system.decimal) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToDoubleTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToDoubleTypeConverter : BindingTypeConverter<string, double>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`double`](https://learn.microsoft.com/dotnet/api/system.double) with `TryParse` under the current culture; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToDoubleTypeConverter()` | Initializes a new instance of the StringToDoubleTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out double result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`double`](https://learn.microsoft.com/dotnet/api/system.double) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToIntegerTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToIntegerTypeConverter : BindingTypeConverter<string, int>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to an [`int`](https://learn.microsoft.com/dotnet/api/system.int32) with `TryParse` under the current culture; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToIntegerTypeConverter()` | Initializes a new instance of the StringToIntegerTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out int result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToLongTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToLongTypeConverter : BindingTypeConverter<string, long>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`long`](https://learn.microsoft.com/dotnet/api/system.int64) with `TryParse` under the current culture; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToLongTypeConverter()` | Initializes a new instance of the StringToLongTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out long result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`long`](https://learn.microsoft.com/dotnet/api/system.int64) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToShortTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToShortTypeConverter : BindingTypeConverter<string, short>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`short`](https://learn.microsoft.com/dotnet/api/system.int16) with `TryParse` under the current culture; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToShortTypeConverter()` | Initializes a new instance of the StringToShortTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out short result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`short`](https://learn.microsoft.com/dotnet/api/system.int16) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToSingleTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToSingleTypeConverter : BindingTypeConverter<string, float>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`float`](https://learn.microsoft.com/dotnet/api/system.single) with `TryParse` under the current culture; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToSingleTypeConverter()` | Initializes a new instance of the StringToSingleTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out float result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`float`](https://learn.microsoft.com/dotnet/api/system.single) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+### Dates and times
+
+[Full description and examples](converters.md).
+
+Types: `ReactiveUI.Binding.DateOnlyToStringTypeConverter`, `ReactiveUI.Binding.DateTimeOffsetToStringTypeConverter`, `ReactiveUI.Binding.DateTimeToStringTypeConverter`, `ReactiveUI.Binding.StringToDateOnlyTypeConverter`, `ReactiveUI.Binding.StringToDateTimeOffsetTypeConverter`, `ReactiveUI.Binding.StringToDateTimeTypeConverter`, `ReactiveUI.Binding.StringToTimeOnlyTypeConverter`, `ReactiveUI.Binding.StringToTimeSpanTypeConverter`, `ReactiveUI.Binding.TimeOnlyToStringTypeConverter`, `ReactiveUI.Binding.TimeSpanToStringTypeConverter`.
+
+#### `DateOnlyToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class DateOnlyToStringTypeConverter : BindingTypeConverter<DateOnly, string>` | Converts a [`DateOnly`](https://learn.microsoft.com/dotnet/api/system.dateonly) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) in the short date format of the current culture. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `DateOnlyToStringTypeConverter()` | Initializes a new instance of the DateOnlyToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(DateOnly from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`DateOnly`](https://learn.microsoft.com/dotnet/api/system.dateonly) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `DateTimeOffsetToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class DateTimeOffsetToStringTypeConverter : BindingTypeConverter<DateTimeOffset, string>` | Converts a [`DateTimeOffset`](https://learn.microsoft.com/dotnet/api/system.datetimeoffset) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) in the general date and time format of the current culture, including the offset. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `DateTimeOffsetToStringTypeConverter()` | Initializes a new instance of the DateTimeOffsetToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(DateTimeOffset from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`DateTimeOffset`](https://learn.microsoft.com/dotnet/api/system.datetimeoffset) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `DateTimeToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class DateTimeToStringTypeConverter : BindingTypeConverter<DateTime, string>` | Converts a [`DateTime`](https://learn.microsoft.com/dotnet/api/system.datetime) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) in the general date and time format of the current culture. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `DateTimeToStringTypeConverter()` | Initializes a new instance of the DateTimeToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(DateTime from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`DateTime`](https://learn.microsoft.com/dotnet/api/system.datetime) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToDateOnlyTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToDateOnlyTypeConverter : BindingTypeConverter<string, DateOnly>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`DateOnly`](https://learn.microsoft.com/dotnet/api/system.dateonly) with `TryParse` under the current culture; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToDateOnlyTypeConverter()` | Initializes a new instance of the StringToDateOnlyTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out DateOnly result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`DateOnly`](https://learn.microsoft.com/dotnet/api/system.dateonly) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToDateTimeOffsetTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToDateTimeOffsetTypeConverter : BindingTypeConverter<string, DateTimeOffset>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`DateTimeOffset`](https://learn.microsoft.com/dotnet/api/system.datetimeoffset) with `TryParse` under the current culture; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToDateTimeOffsetTypeConverter()` | Initializes a new instance of the StringToDateTimeOffsetTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out DateTimeOffset result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`DateTimeOffset`](https://learn.microsoft.com/dotnet/api/system.datetimeoffset) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToDateTimeTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToDateTimeTypeConverter : BindingTypeConverter<string, DateTime>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`DateTime`](https://learn.microsoft.com/dotnet/api/system.datetime) with `TryParse` under the current culture; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToDateTimeTypeConverter()` | Initializes a new instance of the StringToDateTimeTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out DateTime result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`DateTime`](https://learn.microsoft.com/dotnet/api/system.datetime) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToTimeOnlyTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToTimeOnlyTypeConverter : BindingTypeConverter<string, TimeOnly>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`TimeOnly`](https://learn.microsoft.com/dotnet/api/system.timeonly) with `TryParse` under the current culture; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToTimeOnlyTypeConverter()` | Initializes a new instance of the StringToTimeOnlyTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out TimeOnly result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`TimeOnly`](https://learn.microsoft.com/dotnet/api/system.timeonly) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToTimeSpanTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToTimeSpanTypeConverter : BindingTypeConverter<string, TimeSpan>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`TimeSpan`](https://learn.microsoft.com/dotnet/api/system.timespan) with `TryParse` under the current culture; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToTimeSpanTypeConverter()` | Initializes a new instance of the StringToTimeSpanTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out TimeSpan result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`TimeSpan`](https://learn.microsoft.com/dotnet/api/system.timespan) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `TimeOnlyToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class TimeOnlyToStringTypeConverter : BindingTypeConverter<TimeOnly, string>` | Converts a [`TimeOnly`](https://learn.microsoft.com/dotnet/api/system.timeonly) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) in the short time format of the current culture. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `TimeOnlyToStringTypeConverter()` | Initializes a new instance of the TimeOnlyToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(TimeOnly from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`TimeOnly`](https://learn.microsoft.com/dotnet/api/system.timeonly) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `TimeSpanToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class TimeSpanToStringTypeConverter : BindingTypeConverter<TimeSpan, string>` | Converts a [`TimeSpan`](https://learn.microsoft.com/dotnet/api/system.timespan) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) in the culture-invariant constant format (`c`). | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `TimeSpanToStringTypeConverter()` | Initializes a new instance of the TimeSpanToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(TimeSpan from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`TimeSpan`](https://learn.microsoft.com/dotnet/api/system.timespan) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+### Booleans, GUIDs and URIs
+
+[Full description and examples](converters.md).
+
+Types: `ReactiveUI.Binding.BooleanToStringTypeConverter`, `ReactiveUI.Binding.GuidToStringTypeConverter`, `ReactiveUI.Binding.StringToBooleanTypeConverter`, `ReactiveUI.Binding.StringToGuidTypeConverter`, `ReactiveUI.Binding.StringToUriTypeConverter`, `ReactiveUI.Binding.UriToStringTypeConverter`.
+
+#### `BooleanToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class BooleanToStringTypeConverter : BindingTypeConverter<bool, string>` | Converts a [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) as "True" or "False". | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BooleanToStringTypeConverter()` | Initializes a new instance of the BooleanToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(bool from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `GuidToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class GuidToStringTypeConverter : BindingTypeConverter<Guid, string>` | Converts a [`Guid`](https://learn.microsoft.com/dotnet/api/system.guid) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) in the hyphenated `D` format. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GuidToStringTypeConverter()` | Initializes a new instance of the GuidToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(Guid from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`Guid`](https://learn.microsoft.com/dotnet/api/system.guid) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToBooleanTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToBooleanTypeConverter : BindingTypeConverter<string, bool>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) with `TryParse` (case-insensitive `true` or `false`); a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToBooleanTypeConverter()` | Initializes a new instance of the StringToBooleanTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out bool result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToGuidTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToGuidTypeConverter : BindingTypeConverter<string, Guid>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`Guid`](https://learn.microsoft.com/dotnet/api/system.guid) with `TryParse`; a null or unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToGuidTypeConverter()` | Initializes a new instance of the StringToGuidTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out Guid result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`Guid`](https://learn.microsoft.com/dotnet/api/system.guid) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToUriTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToUriTypeConverter : BindingTypeConverter<string, Uri>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a [`Uri`](https://learn.microsoft.com/dotnet/api/system.uri) with `TryCreate`, accepting relative and absolute URIs; a null string or text that cannot form a URI fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToUriTypeConverter()` | Initializes a new instance of the StringToUriTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out Uri? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`Uri?`](https://learn.microsoft.com/dotnet/api/system.uri) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `UriToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class UriToStringTypeConverter : BindingTypeConverter<Uri, string>` | Converts a [`Uri`](https://learn.microsoft.com/dotnet/api/system.uri) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) with `ToString`; a null value fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `UriToStringTypeConverter()` | Initializes a new instance of the UriToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(Uri? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`Uri?`](https://learn.microsoft.com/dotnet/api/system.uri) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+### Nullable values
+
+[Full description and examples](converters.md).
+
+Types: `ReactiveUI.Binding.ByteToNullableByteTypeConverter`, `ReactiveUI.Binding.DecimalToNullableDecimalTypeConverter`, `ReactiveUI.Binding.DoubleToNullableDoubleTypeConverter`, `ReactiveUI.Binding.IntegerToNullableIntegerTypeConverter`, `ReactiveUI.Binding.LongToNullableLongTypeConverter`, `ReactiveUI.Binding.NullableBooleanToStringTypeConverter`, `ReactiveUI.Binding.NullableByteToByteTypeConverter`, `ReactiveUI.Binding.NullableByteToStringTypeConverter`, `ReactiveUI.Binding.NullableDateOnlyToStringTypeConverter`, `ReactiveUI.Binding.NullableDateTimeOffsetToStringTypeConverter`, `ReactiveUI.Binding.NullableDateTimeToStringTypeConverter`, `ReactiveUI.Binding.NullableDecimalToDecimalTypeConverter`, `ReactiveUI.Binding.NullableDecimalToStringTypeConverter`, `ReactiveUI.Binding.NullableDoubleToDoubleTypeConverter`, `ReactiveUI.Binding.NullableDoubleToStringTypeConverter`, `ReactiveUI.Binding.NullableGuidToStringTypeConverter`, `ReactiveUI.Binding.NullableIntegerToIntegerTypeConverter`, `ReactiveUI.Binding.NullableIntegerToStringTypeConverter`, `ReactiveUI.Binding.NullableLongToLongTypeConverter`, `ReactiveUI.Binding.NullableLongToStringTypeConverter`, `ReactiveUI.Binding.NullableShortToShortTypeConverter`, `ReactiveUI.Binding.NullableShortToStringTypeConverter`, `ReactiveUI.Binding.NullableSingleToSingleTypeConverter`, `ReactiveUI.Binding.NullableSingleToStringTypeConverter`, `ReactiveUI.Binding.NullableTimeOnlyToStringTypeConverter`, `ReactiveUI.Binding.NullableTimeSpanToStringTypeConverter`, `ReactiveUI.Binding.ShortToNullableShortTypeConverter`, `ReactiveUI.Binding.SingleToNullableSingleTypeConverter`, `ReactiveUI.Binding.StringToNullableBooleanTypeConverter`, `ReactiveUI.Binding.StringToNullableByteTypeConverter`, `ReactiveUI.Binding.StringToNullableDateOnlyTypeConverter`, `ReactiveUI.Binding.StringToNullableDateTimeOffsetTypeConverter`, `ReactiveUI.Binding.StringToNullableDateTimeTypeConverter`, `ReactiveUI.Binding.StringToNullableDecimalTypeConverter`, `ReactiveUI.Binding.StringToNullableDoubleTypeConverter`, `ReactiveUI.Binding.StringToNullableGuidTypeConverter`, `ReactiveUI.Binding.StringToNullableIntegerTypeConverter`, `ReactiveUI.Binding.StringToNullableLongTypeConverter`, `ReactiveUI.Binding.StringToNullableShortTypeConverter`, `ReactiveUI.Binding.StringToNullableSingleTypeConverter`, `ReactiveUI.Binding.StringToNullableTimeOnlyTypeConverter`, `ReactiveUI.Binding.StringToNullableTimeSpanTypeConverter`.
+
+#### `ByteToNullableByteTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ByteToNullableByteTypeConverter` | Converts a [`byte`](https://learn.microsoft.com/dotnet/api/system.byte) to a nullable [`byte`](https://learn.microsoft.com/dotnet/api/system.byte); the conversion always succeeds. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ByteToNullableByteTypeConverter()` | Initializes a new instance of the ByteToNullableByteTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(byte from, object? conversionHint, out byte? result)` | Converts a value to the target type without boxing. | [`byte`](https://learn.microsoft.com/dotnet/api/system.byte) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`byte?`](https://learn.microsoft.com/dotnet/api/system.byte) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `DecimalToNullableDecimalTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class DecimalToNullableDecimalTypeConverter` | Converts a [`decimal`](https://learn.microsoft.com/dotnet/api/system.decimal) to a nullable [`decimal`](https://learn.microsoft.com/dotnet/api/system.decimal); the conversion always succeeds. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `DecimalToNullableDecimalTypeConverter()` | Initializes a new instance of the DecimalToNullableDecimalTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(decimal from, object? conversionHint, out decimal? result)` | Converts a value to the target type without boxing. | [`decimal`](https://learn.microsoft.com/dotnet/api/system.decimal) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`decimal?`](https://learn.microsoft.com/dotnet/api/system.decimal) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `DoubleToNullableDoubleTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class DoubleToNullableDoubleTypeConverter` | Converts a [`double`](https://learn.microsoft.com/dotnet/api/system.double) to a nullable [`double`](https://learn.microsoft.com/dotnet/api/system.double); the conversion always succeeds. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `DoubleToNullableDoubleTypeConverter()` | Initializes a new instance of the DoubleToNullableDoubleTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(double from, object? conversionHint, out double? result)` | Converts a value to the target type without boxing. | [`double`](https://learn.microsoft.com/dotnet/api/system.double) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`double?`](https://learn.microsoft.com/dotnet/api/system.double) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `IntegerToNullableIntegerTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class IntegerToNullableIntegerTypeConverter` | Converts an [`int`](https://learn.microsoft.com/dotnet/api/system.int32) to a nullable [`int`](https://learn.microsoft.com/dotnet/api/system.int32); the conversion always succeeds. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `IntegerToNullableIntegerTypeConverter()` | Initializes a new instance of the IntegerToNullableIntegerTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(int from, object? conversionHint, out int? result)` | Converts a value to the target type without boxing. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`int?`](https://learn.microsoft.com/dotnet/api/system.int32) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `LongToNullableLongTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class LongToNullableLongTypeConverter` | Converts a [`long`](https://learn.microsoft.com/dotnet/api/system.int64) to a nullable [`long`](https://learn.microsoft.com/dotnet/api/system.int64); the conversion always succeeds. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `LongToNullableLongTypeConverter()` | Initializes a new instance of the LongToNullableLongTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(long from, object? conversionHint, out long? result)` | Converts a value to the target type without boxing. | [`long`](https://learn.microsoft.com/dotnet/api/system.int64) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`long?`](https://learn.microsoft.com/dotnet/api/system.int64) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `NullableBooleanToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableBooleanToStringTypeConverter : BindingTypeConverter<bool?, string>` | Converts a nullable [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) as "True" or "False". A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableBooleanToStringTypeConverter()` | Initializes a new instance of the NullableBooleanToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(bool? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`bool?`](https://learn.microsoft.com/dotnet/api/system.boolean) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableByteToByteTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableByteToByteTypeConverter` | Converts a nullable [`byte`](https://learn.microsoft.com/dotnet/api/system.byte) to a [`byte`](https://learn.microsoft.com/dotnet/api/system.byte); a null value fails the conversion. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableByteToByteTypeConverter()` | Initializes a new instance of the NullableByteToByteTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(byte? from, object? conversionHint, out byte result)` | Converts a value to the target type without boxing. | [`byte?`](https://learn.microsoft.com/dotnet/api/system.byte) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`byte`](https://learn.microsoft.com/dotnet/api/system.byte) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `NullableByteToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableByteToStringTypeConverter : BindingTypeConverter<byte?, string>` | Converts a nullable [`byte`](https://learn.microsoft.com/dotnet/api/system.byte) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the minimum digit count (the `D` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableByteToStringTypeConverter()` | Initializes a new instance of the NullableByteToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(byte? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`byte?`](https://learn.microsoft.com/dotnet/api/system.byte) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableDateOnlyToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableDateOnlyToStringTypeConverter : BindingTypeConverter<DateOnly?, string>` | Converts a nullable [`DateOnly`](https://learn.microsoft.com/dotnet/api/system.dateonly) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) in the short date format of the current culture. A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableDateOnlyToStringTypeConverter()` | Initializes a new instance of the NullableDateOnlyToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(DateOnly? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`DateOnly?`](https://learn.microsoft.com/dotnet/api/system.dateonly) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableDateTimeOffsetToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableDateTimeOffsetToStringTypeConverter : BindingTypeConverter<DateTimeOffset?, string>` | Converts a nullable [`DateTimeOffset`](https://learn.microsoft.com/dotnet/api/system.datetimeoffset) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) in the general date and time format of the current culture, including the offset. A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableDateTimeOffsetToStringTypeConverter()` | Initializes a new instance of the NullableDateTimeOffsetToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(DateTimeOffset? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`DateTimeOffset?`](https://learn.microsoft.com/dotnet/api/system.datetimeoffset) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableDateTimeToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableDateTimeToStringTypeConverter : BindingTypeConverter<DateTime?, string>` | Converts a nullable [`DateTime`](https://learn.microsoft.com/dotnet/api/system.datetime) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) in the general date and time format of the current culture. A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableDateTimeToStringTypeConverter()` | Initializes a new instance of the NullableDateTimeToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(DateTime? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`DateTime?`](https://learn.microsoft.com/dotnet/api/system.datetime) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableDecimalToDecimalTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableDecimalToDecimalTypeConverter` | Converts a nullable [`decimal`](https://learn.microsoft.com/dotnet/api/system.decimal) to a [`decimal`](https://learn.microsoft.com/dotnet/api/system.decimal); a null value fails the conversion. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableDecimalToDecimalTypeConverter()` | Initializes a new instance of the NullableDecimalToDecimalTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(decimal? from, object? conversionHint, out decimal result)` | Converts a value to the target type without boxing. | [`decimal?`](https://learn.microsoft.com/dotnet/api/system.decimal) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`decimal`](https://learn.microsoft.com/dotnet/api/system.decimal) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `NullableDecimalToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableDecimalToStringTypeConverter : BindingTypeConverter<decimal?, string>` | Converts a nullable [`decimal`](https://learn.microsoft.com/dotnet/api/system.decimal) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the number of decimal places (the `F` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableDecimalToStringTypeConverter()` | Initializes a new instance of the NullableDecimalToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(decimal? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`decimal?`](https://learn.microsoft.com/dotnet/api/system.decimal) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableDoubleToDoubleTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableDoubleToDoubleTypeConverter` | Converts a nullable [`double`](https://learn.microsoft.com/dotnet/api/system.double) to a [`double`](https://learn.microsoft.com/dotnet/api/system.double); a null value fails the conversion. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableDoubleToDoubleTypeConverter()` | Initializes a new instance of the NullableDoubleToDoubleTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(double? from, object? conversionHint, out double result)` | Converts a value to the target type without boxing. | [`double?`](https://learn.microsoft.com/dotnet/api/system.double) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`double`](https://learn.microsoft.com/dotnet/api/system.double) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `NullableDoubleToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableDoubleToStringTypeConverter : BindingTypeConverter<double?, string>` | Converts a nullable [`double`](https://learn.microsoft.com/dotnet/api/system.double) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the number of decimal places (the `F` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableDoubleToStringTypeConverter()` | Initializes a new instance of the NullableDoubleToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(double? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`double?`](https://learn.microsoft.com/dotnet/api/system.double) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableGuidToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableGuidToStringTypeConverter : BindingTypeConverter<Guid?, string>` | Converts a nullable [`Guid`](https://learn.microsoft.com/dotnet/api/system.guid) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) in the hyphenated `D` format. A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableGuidToStringTypeConverter()` | Initializes a new instance of the NullableGuidToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(Guid? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`Guid?`](https://learn.microsoft.com/dotnet/api/system.guid) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableIntegerToIntegerTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableIntegerToIntegerTypeConverter` | Converts a nullable [`int`](https://learn.microsoft.com/dotnet/api/system.int32) to an [`int`](https://learn.microsoft.com/dotnet/api/system.int32); a null value fails the conversion. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableIntegerToIntegerTypeConverter()` | Initializes a new instance of the NullableIntegerToIntegerTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(int? from, object? conversionHint, out int result)` | Converts a value to the target type without boxing. | [`int?`](https://learn.microsoft.com/dotnet/api/system.int32) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `NullableIntegerToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableIntegerToStringTypeConverter : BindingTypeConverter<int?, string>` | Converts a nullable [`int`](https://learn.microsoft.com/dotnet/api/system.int32) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the minimum digit count (the `D` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableIntegerToStringTypeConverter()` | Initializes a new instance of the NullableIntegerToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(int? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`int?`](https://learn.microsoft.com/dotnet/api/system.int32) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableLongToLongTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableLongToLongTypeConverter` | Converts a nullable [`long`](https://learn.microsoft.com/dotnet/api/system.int64) to a [`long`](https://learn.microsoft.com/dotnet/api/system.int64); a null value fails the conversion. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableLongToLongTypeConverter()` | Initializes a new instance of the NullableLongToLongTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(long? from, object? conversionHint, out long result)` | Converts a value to the target type without boxing. | [`long?`](https://learn.microsoft.com/dotnet/api/system.int64) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`long`](https://learn.microsoft.com/dotnet/api/system.int64) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `NullableLongToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableLongToStringTypeConverter : BindingTypeConverter<long?, string>` | Converts a nullable [`long`](https://learn.microsoft.com/dotnet/api/system.int64) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the minimum digit count (the `D` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableLongToStringTypeConverter()` | Initializes a new instance of the NullableLongToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(long? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`long?`](https://learn.microsoft.com/dotnet/api/system.int64) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableShortToShortTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableShortToShortTypeConverter` | Converts a nullable [`short`](https://learn.microsoft.com/dotnet/api/system.int16) to a [`short`](https://learn.microsoft.com/dotnet/api/system.int16); a null value fails the conversion. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableShortToShortTypeConverter()` | Initializes a new instance of the NullableShortToShortTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(short? from, object? conversionHint, out short result)` | Converts a value to the target type without boxing. | [`short?`](https://learn.microsoft.com/dotnet/api/system.int16) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`short`](https://learn.microsoft.com/dotnet/api/system.int16) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `NullableShortToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableShortToStringTypeConverter : BindingTypeConverter<short?, string>` | Converts a nullable [`short`](https://learn.microsoft.com/dotnet/api/system.int16) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the minimum digit count (the `D` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableShortToStringTypeConverter()` | Initializes a new instance of the NullableShortToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(short? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`short?`](https://learn.microsoft.com/dotnet/api/system.int16) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableSingleToSingleTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableSingleToSingleTypeConverter` | Converts a nullable [`float`](https://learn.microsoft.com/dotnet/api/system.single) to a [`float`](https://learn.microsoft.com/dotnet/api/system.single); a null value fails the conversion. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableSingleToSingleTypeConverter()` | Initializes a new instance of the NullableSingleToSingleTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(float? from, object? conversionHint, out float result)` | Converts a value to the target type without boxing. | [`float?`](https://learn.microsoft.com/dotnet/api/system.single) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`float`](https://learn.microsoft.com/dotnet/api/system.single) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `NullableSingleToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableSingleToStringTypeConverter : BindingTypeConverter<float?, string>` | Converts a nullable [`float`](https://learn.microsoft.com/dotnet/api/system.single) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) using the current culture. An [`int`](https://learn.microsoft.com/dotnet/api/system.int32) hint gives the number of decimal places (the `F` format) and a [`string`](https://learn.microsoft.com/dotnet/api/system.string) hint gives the format string; a malformed format throws [`FormatException`](https://learn.microsoft.com/dotnet/api/system.formatexception). A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableSingleToStringTypeConverter()` | Initializes a new instance of the NullableSingleToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(float? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`float?`](https://learn.microsoft.com/dotnet/api/system.single) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableTimeOnlyToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableTimeOnlyToStringTypeConverter : BindingTypeConverter<TimeOnly?, string>` | Converts a nullable [`TimeOnly`](https://learn.microsoft.com/dotnet/api/system.timeonly) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) in the short time format of the current culture. A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableTimeOnlyToStringTypeConverter()` | Initializes a new instance of the NullableTimeOnlyToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(TimeOnly? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`TimeOnly?`](https://learn.microsoft.com/dotnet/api/system.timeonly) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `NullableTimeSpanToStringTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NullableTimeSpanToStringTypeConverter : BindingTypeConverter<TimeSpan?, string>` | Converts a nullable [`TimeSpan`](https://learn.microsoft.com/dotnet/api/system.timespan) to a [`string`](https://learn.microsoft.com/dotnet/api/system.string) in the culture-invariant constant format (`c`). A null value succeeds with a null string. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NullableTimeSpanToStringTypeConverter()` | Initializes a new instance of the NullableTimeSpanToStringTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(TimeSpan? from, object? conversionHint, out string? result)` | Converts a value to the target type without boxing. | [`TimeSpan?`](https://learn.microsoft.com/dotnet/api/system.timespan) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `ShortToNullableShortTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ShortToNullableShortTypeConverter` | Converts a [`short`](https://learn.microsoft.com/dotnet/api/system.int16) to a nullable [`short`](https://learn.microsoft.com/dotnet/api/system.int16); the conversion always succeeds. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ShortToNullableShortTypeConverter()` | Initializes a new instance of the ShortToNullableShortTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(short from, object? conversionHint, out short? result)` | Converts a value to the target type without boxing. | [`short`](https://learn.microsoft.com/dotnet/api/system.int16) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`short?`](https://learn.microsoft.com/dotnet/api/system.int16) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `SingleToNullableSingleTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class SingleToNullableSingleTypeConverter` | Converts a [`float`](https://learn.microsoft.com/dotnet/api/system.single) to a nullable [`float`](https://learn.microsoft.com/dotnet/api/system.single); the conversion always succeeds. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `SingleToNullableSingleTypeConverter()` | Initializes a new instance of the SingleToNullableSingleTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvert(float from, object? conversionHint, out float? result)` | Converts a value to the target type without boxing. | [`float`](https://learn.microsoft.com/dotnet/api/system.single) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`float?`](https://learn.microsoft.com/dotnet/api/system.single) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `StringToNullableBooleanTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableBooleanTypeConverter : BindingTypeConverter<string, bool?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) with `TryParse` (case-insensitive `true` or `false`); a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableBooleanTypeConverter()` | Initializes a new instance of the StringToNullableBooleanTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out bool? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`bool?`](https://learn.microsoft.com/dotnet/api/system.boolean) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableByteTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableByteTypeConverter : BindingTypeConverter<string, byte?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`byte`](https://learn.microsoft.com/dotnet/api/system.byte) with `TryParse` under the current culture; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableByteTypeConverter()` | Initializes a new instance of the StringToNullableByteTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out byte? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`byte?`](https://learn.microsoft.com/dotnet/api/system.byte) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableDateOnlyTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableDateOnlyTypeConverter : BindingTypeConverter<string, DateOnly?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`DateOnly`](https://learn.microsoft.com/dotnet/api/system.dateonly) with `TryParse` under the current culture; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableDateOnlyTypeConverter()` | Initializes a new instance of the StringToNullableDateOnlyTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out DateOnly? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`DateOnly?`](https://learn.microsoft.com/dotnet/api/system.dateonly) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableDateTimeOffsetTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableDateTimeOffsetTypeConverter : BindingTypeConverter<string, DateTimeOffset?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`DateTimeOffset`](https://learn.microsoft.com/dotnet/api/system.datetimeoffset) with `TryParse` under the current culture; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableDateTimeOffsetTypeConverter()` | Initializes a new instance of the StringToNullableDateTimeOffsetTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out DateTimeOffset? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`DateTimeOffset?`](https://learn.microsoft.com/dotnet/api/system.datetimeoffset) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableDateTimeTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableDateTimeTypeConverter : BindingTypeConverter<string, DateTime?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`DateTime`](https://learn.microsoft.com/dotnet/api/system.datetime) with `TryParse` under the current culture; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableDateTimeTypeConverter()` | Initializes a new instance of the StringToNullableDateTimeTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out DateTime? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`DateTime?`](https://learn.microsoft.com/dotnet/api/system.datetime) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableDecimalTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableDecimalTypeConverter : BindingTypeConverter<string, decimal?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`decimal`](https://learn.microsoft.com/dotnet/api/system.decimal) with `TryParse` under the current culture; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableDecimalTypeConverter()` | Initializes a new instance of the StringToNullableDecimalTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out decimal? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`decimal?`](https://learn.microsoft.com/dotnet/api/system.decimal) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableDoubleTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableDoubleTypeConverter : BindingTypeConverter<string, double?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`double`](https://learn.microsoft.com/dotnet/api/system.double) with `TryParse` under the current culture; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableDoubleTypeConverter()` | Initializes a new instance of the StringToNullableDoubleTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out double? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`double?`](https://learn.microsoft.com/dotnet/api/system.double) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableGuidTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableGuidTypeConverter : BindingTypeConverter<string, Guid?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`Guid`](https://learn.microsoft.com/dotnet/api/system.guid) with `TryParse`; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableGuidTypeConverter()` | Initializes a new instance of the StringToNullableGuidTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out Guid? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`Guid?`](https://learn.microsoft.com/dotnet/api/system.guid) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableIntegerTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableIntegerTypeConverter : BindingTypeConverter<string, int?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`int`](https://learn.microsoft.com/dotnet/api/system.int32) with `TryParse` under the current culture; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableIntegerTypeConverter()` | Initializes a new instance of the StringToNullableIntegerTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out int? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`int?`](https://learn.microsoft.com/dotnet/api/system.int32) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableLongTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableLongTypeConverter : BindingTypeConverter<string, long?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`long`](https://learn.microsoft.com/dotnet/api/system.int64) with `TryParse` under the current culture; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableLongTypeConverter()` | Initializes a new instance of the StringToNullableLongTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out long? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`long?`](https://learn.microsoft.com/dotnet/api/system.int64) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableShortTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableShortTypeConverter : BindingTypeConverter<string, short?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`short`](https://learn.microsoft.com/dotnet/api/system.int16) with `TryParse` under the current culture; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableShortTypeConverter()` | Initializes a new instance of the StringToNullableShortTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out short? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`short?`](https://learn.microsoft.com/dotnet/api/system.int16) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableSingleTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableSingleTypeConverter : BindingTypeConverter<string, float?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`float`](https://learn.microsoft.com/dotnet/api/system.single) with `TryParse` under the current culture; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableSingleTypeConverter()` | Initializes a new instance of the StringToNullableSingleTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out float? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`float?`](https://learn.microsoft.com/dotnet/api/system.single) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableTimeOnlyTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableTimeOnlyTypeConverter : BindingTypeConverter<string, TimeOnly?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`TimeOnly`](https://learn.microsoft.com/dotnet/api/system.timeonly) with `TryParse` under the current culture; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableTimeOnlyTypeConverter()` | Initializes a new instance of the StringToNullableTimeOnlyTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out TimeOnly? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`TimeOnly?`](https://learn.microsoft.com/dotnet/api/system.timeonly) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `StringToNullableTimeSpanTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringToNullableTimeSpanTypeConverter : BindingTypeConverter<string, TimeSpan?>` | Converts a [`string`](https://learn.microsoft.com/dotnet/api/system.string) to a nullable [`TimeSpan`](https://learn.microsoft.com/dotnet/api/system.timespan) with `TryParse` under the current culture; a null or empty string succeeds with a null result and an unparseable string fails. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringToNullableTimeSpanTypeConverter()` | Initializes a new instance of the StringToNullableTimeSpanTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(string? from, object? conversionHint, out TimeSpan? result)` | Converts a value to the target type without boxing. | [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`TimeSpan?`](https://learn.microsoft.com/dotnet/api/system.timespan) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+### Custom converters
+
+[Full description and examples](converters.md).
+
+Types: `ReactiveUI.Binding.BindingTypeConverter<TFrom, TTo>`, `ReactiveUI.Binding.Fallback.TwoWayConverterPair<TSourceProp, TTargetProp>`, `ReactiveUI.Binding.Fallback.TwoWayConverters`, `ReactiveUI.Binding.IBindingTypeConverter`, `ReactiveUI.Binding.IBindingTypeConverter<TFrom, TTo>`, `ReactiveUI.Binding.ISetMethodBindingConverter`.
+
+#### `BindingTypeConverter<TFrom, TTo>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `abstract class BindingTypeConverter<TFrom, TTo>` | Base class for a converter between one type pair; it supplies `FromType`, `ToType` and an object-based `TryConvertTyped` over the typed `TryConvert`. | `TFrom`: The source type to convert from; `TTo`: The target type to convert to | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `protected BindingTypeConverter()` | Initializes a new instance of the BindingTypeConverter<TFrom, TTo> class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `abstract GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `abstract TryConvert(TFrom? from, object? conversionHint, out TTo? result)` | Converts a value to the target type without boxing. | `TFrom?` `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out `TTo?` `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value by casting it to `TFrom` and calling `TryConvert`. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value. A null is passed on as `default` when `TFrom` can hold null, and fails when it cannot; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, passed to `TryConvert` unchanged; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value, or null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `false` when `from` is not a `TFrom` or `TryConvert` fails; otherwise `true`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `TwoWayConverterPair<TSourceProp, TTargetProp>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed record TwoWayConverterPair<TSourceProp, TTargetProp>` | The pair of conversions a two-way binding needs to move a value in either direction. | `TSourceProp`: The type of the source property; `TTargetProp`: The type of the target property | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `TwoWayConverterPair(Func<TSourceProp, TTargetProp> Forward, Func<TTargetProp, TSourceProp> Reverse)` | The pair of conversions a two-way binding needs to move a value in either direction. | [`Func<TSourceProp, TTargetProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `Forward`: Converts a source value to the target's type; [`Func<TTargetProp, TSourceProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `Reverse`: Converts a target value back to the source's type | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Forward { get; init; }` | Converts a source value to the target's type. | None. | [`Func<TSourceProp, TTargetProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) |
+| `Reverse { get; init; }` | Converts a target value back to the source's type. | None. | [`Func<TTargetProp, TSourceProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) |
+
+#### `TwoWayConverters`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class TwoWayConverters` | Builds a [`TwoWayConverterPair<TSourceProp, TTargetProp>`](converters.md) without naming its type arguments. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Create<TSourceProp, TTargetProp>(Func<TSourceProp, TTargetProp> forward, Func<TTargetProp, TSourceProp> reverse)` | Pairs a forward and a reverse conversion. | `TSourceProp`: The type of the source property; `TTargetProp`: The type of the target property; [`Func<TSourceProp, TTargetProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `forward`: Converts a source value to the target's type; [`Func<TTargetProp, TSourceProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `reverse`: Converts a target value back to the source's type | [`TwoWayConverterPair<TSourceProp, TTargetProp>`](converters.md): The paired conversions. |
+
+#### `IBindingTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IBindingTypeConverter` | Converts values from `FromType` to `ToType` for the binding APIs. Register an implementation to teach a binding how to convert between two types. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `IBindingTypeConverter<TFrom, TTo>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IBindingTypeConverter<TFrom, TTo>` | Extends [`IBindingTypeConverter`](converters.md) with a typed `TryConvert` for one type pair. | `TFrom`: The source type to convert from; `TTo`: The target type to convert to | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `TryConvert(TFrom? from, object? conversionHint, out TTo? result)` | Converts a value to the target type without boxing. | `TFrom?` `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out `TTo?` `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `ISetMethodBindingConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface ISetMethodBindingConverter` | Replaces how a binding writes a value to its target, for example to fill a collection instead of assigning a property. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects(Type? fromType, Type? toType)` | Returns this converter's priority for writing a value of one type to a target of another. | [`Type?`](https://learn.microsoft.com/dotnet/api/system.type) `fromType`: The type of the value being written; may be null; [`Type?`](https://learn.microsoft.com/dotnet/api/system.type) `toType`: The type of the target being written to; may be null | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when `PerformSet` applies; zero or less excludes the converter. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `PerformSet(object? toTarget, object? newValue, object?[]? arguments)` | Writes a value to the target. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `toTarget`: The object being written to; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `newValue`: The value to write; [`object?[]?`](https://learn.microsoft.com/dotnet/api/system.object) `arguments`: The index arguments for an indexer target; a generated collection write passes null | [`object?`](https://learn.microsoft.com/dotnet/api/system.object): The result of the write; a generated collection write casts it to the target type and reports it as the new value. |
+
+### Converter registries
+
+[Full description and examples](converters.md).
+
+Types: `ReactiveUI.Binding.BindingConverters`, `ReactiveUI.Binding.BindingTypeConverterRegistry`, `ReactiveUI.Binding.ConverterService`, `ReactiveUI.Binding.DefaultConverterRegistration`, `ReactiveUI.Binding.SetMethodBindingConverterRegistry`.
+
+#### `BindingConverters`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class BindingConverters` | Provides the process-wide [`ConverterService`](converters.md) that generated and runtime bindings convert through. | None. | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Current { get; }` | Gets the converter service in use. | None. | [`ConverterService`](converters.md) |
+
+#### `BindingTypeConverterRegistry`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class BindingTypeConverterRegistry` | Holds typed binding converters grouped by their exact source and target type pair. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BindingTypeConverterRegistry()` | Initializes a new instance of the BindingTypeConverterRegistry class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAllConverters()` | Returns a copy of every registered converter, in no particular order across type pairs. | None. | [`IEnumerable<IBindingTypeConverter>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1): The converters registered at the time of the call; empty when none are registered. Later registrations do not change the returned sequence. |
+| `Register(IBindingTypeConverter converter)` | Registers a converter under its `FromType` and `ToType` pair. | [`IBindingTypeConverter`](converters.md) `converter`: The converter to register | — |
+| `TryGetConverter(Type fromType, Type toType)` | Returns the registered converter with the highest positive affinity for the exact type pair. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `fromType`: The source type to convert from; [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `toType`: The target type to convert to | [`IBindingTypeConverter?`](converters.md): The best converter, the earliest registered one on a tie in affinity; `null` when none is registered for the pair or every one reports an affinity of zero or less. |
+
+#### `ConverterService`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ConverterService` | Owns the typed, fallback and set-method converter registries and resolves the best converter for a type pair. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ConverterService()` | Initializes a new instance of the [`ConverterService`](converters.md) class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ResolveConverter(Type fromType, Type toType)` | Returns the best typed converter for the type pair, or else the best fallback converter. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `fromType`: The source type to convert from; [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `toType`: The target type to convert to | [`object?`](https://learn.microsoft.com/dotnet/api/system.object): An [`IBindingTypeConverter`](converters.md) or an [`IBindingFallbackConverter`](converters.md); a typed converter always wins over a fallback one whatever their affinities. `null` when neither registry has a match. |
+| `ResolveSetMethodConverter(Type? fromType, Type? toType)` | Returns the best set-method converter for the type pair. | [`Type?`](https://learn.microsoft.com/dotnet/api/system.type) `fromType`: The type of the value being written; may be null; [`Type?`](https://learn.microsoft.com/dotnet/api/system.type) `toType`: The type of the target being written to; may be null | [`ISetMethodBindingConverter?`](converters.md): The converter with the highest positive affinity, or `null` when none applies. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FallbackConverters { get; }` | Gets the registry of fallback converters, consulted when no typed converter applies. | None. | [`BindingFallbackConverterRegistry`](converters.md) |
+| `SetMethodConverters { get; }` | Gets the registry of converters that replace how a binding writes to its target. | None. | [`SetMethodBindingConverterRegistry`](converters.md) |
+| `TypedConverters { get; }` | Gets the registry of typed converters, each matched to an exact source and target type pair. | None. | [`BindingTypeConverterRegistry`](converters.md) |
+
+#### `DefaultConverterRegistration`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class DefaultConverterRegistration` | Registers the built-in typed converters with a [`ConverterService`](converters.md). | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `RegisterDefaults(ConverterService service)` | Registers the string identity, equality, boolean, Guid, Uri, numeric and date and time converters, each with its nullable forms. | [`ConverterService`](converters.md) `service`: The converter service to register the converters with | — |
+
+#### `SetMethodBindingConverterRegistry`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class SetMethodBindingConverterRegistry` | Holds set-method binding converters, which are asked about a type pair at lookup time rather than grouped by it. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `SetMethodBindingConverterRegistry()` | Initializes a new instance of the SetMethodBindingConverterRegistry class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAllConverters()` | Returns a copy of every registered set-method converter, in registration order. | None. | [`IEnumerable<ISetMethodBindingConverter>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1): The converters registered at the time of the call; empty when none are registered. |
+| `Register(ISetMethodBindingConverter converter)` | Registers a set-method binding converter. | [`ISetMethodBindingConverter`](converters.md) `converter`: The converter to register | — |
+| `TryGetConverter(Type? fromType, Type? toType)` | Asks each set-method converter for its affinity to the type pair and returns the highest positive one. | [`Type?`](https://learn.microsoft.com/dotnet/api/system.type) `fromType`: The type of the value being written; may be null; [`Type?`](https://learn.microsoft.com/dotnet/api/system.type) `toType`: The type of the target being written to; may be null | [`ISetMethodBindingConverter?`](converters.md): The converter with the highest positive affinity, the earliest registered one on a tie; `null` when none reports a positive affinity. |
+
+### Fallback converters
+
+[Full description and examples](converters.md).
+
+Types: `ReactiveUI.Binding.BindingFallbackConverterRegistry`, `ReactiveUI.Binding.IBindingFallbackConverter`.
+
+#### `BindingFallbackConverterRegistry`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class BindingFallbackConverterRegistry` | Holds fallback binding converters, which are asked about a type pair at lookup time rather than grouped by it. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BindingFallbackConverterRegistry()` | Initializes a new instance of the BindingFallbackConverterRegistry class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAllConverters()` | Returns a copy of every registered fallback converter, in registration order. | None. | [`IEnumerable<IBindingFallbackConverter>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1): The converters registered at the time of the call; empty when none are registered. |
+| `Register(IBindingFallbackConverter converter)` | Registers a fallback binding converter. | [`IBindingFallbackConverter`](converters.md) `converter`: The converter to register | — |
+| `TryGetConverter(Type fromType, Type toType)` | Asks each fallback converter for its affinity to the type pair and returns the highest positive one. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `fromType`: The source type to convert from; [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `toType`: The target type to convert to | [`IBindingFallbackConverter?`](converters.md): The converter with the highest positive affinity, the earliest registered one on a tie; `null` when none reports a positive affinity. |
+
+#### `IBindingFallbackConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IBindingFallbackConverter` | Converts runtime type pairs that no typed converter covers. The converter service asks the fallback converters only when no typed converter with a positive affinity is registered for the pair. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects(Type fromType, Type toType)` | Calculates affinity for the specified runtime type pair. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `fromType`: The runtime source type; [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `toType`: The target type | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter handles the pair, where a higher value wins over other fallback converters; zero or less when it does not. |
+| `TryConvert(Type fromType, object from, Type toType, object? conversionHint, out object? result)` | Attempts to convert the value to the target type. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `fromType`: The runtime source type (guaranteed non-null); [`object`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The value to convert (guaranteed non-null); [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `toType`: The target type (guaranteed non-null); [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined conversion hint (e.g., format string, culture); out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value. Implementations must produce a non-null value when returning `true` | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+### Migrating converters
+
+[Full description and examples](converters.md).
+
+Types: `ReactiveUI.Binding.ConverterMigrationHelper`, `ReactiveUI.Binding.ConverterMigrationHelperMixins`, `ReactiveUI.Binding.ExtractedConverters`.
+
+#### `ConverterMigrationHelper`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class ConverterMigrationHelper` | Reads converters that were registered with a Splat dependency resolver. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ExtractConverters(IReadonlyDependencyResolver resolver)` | Collects every typed, fallback and set-method converter registered with a Splat resolver, without registering them anywhere. | `IReadonlyDependencyResolver` `resolver`: The Splat resolver to read | [`ExtractedConverters`](converters.md): The converters the resolver holds, in the order it returns them; a null registration is skipped. |
+
+#### `ConverterMigrationHelperMixins`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class ConverterMigrationHelperMixins` | Extension members that import Splat-registered converters into a [`ConverterService`](converters.md). | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ConverterService.ImportFrom(IReadonlyDependencyResolver resolver)` | Registers the converters held by a Splat resolver with this service. | [`ConverterService`](converters.md) `converterService` (receiver); `IReadonlyDependencyResolver` `resolver`: The Splat resolver to import converters from | — |
+
+#### `ExtractedConverters`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed record ExtractedConverters` | The converters found in a dependency resolver, grouped by the role each one fills. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ExtractedConverters(IList<IBindingTypeConverter> TypedConverters, IList<IBindingFallbackConverter> FallbackConverters, IList<ISetMethodBindingConverter> SetMethodConverters)` | The converters found in a dependency resolver, grouped by the role each one fills. | [`IList<IBindingTypeConverter>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ilist-1) `TypedConverters`: The converters that move a value between two known types; [`IList<IBindingFallbackConverter>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ilist-1) `FallbackConverters`: The converters consulted when no typed converter matches; [`IList<ISetMethodBindingConverter>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ilist-1) `SetMethodConverters`: The converters that write a value to a target rather than return one | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FallbackConverters { get; init; }` | The converters consulted when no typed converter matches. | None. | [`IList<IBindingFallbackConverter>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ilist-1) |
+| `SetMethodConverters { get; init; }` | The converters that write a value to a target rather than return one. | None. | [`IList<ISetMethodBindingConverter>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ilist-1) |
+| `TypedConverters { get; init; }` | The converters that move a value between two known types. | None. | [`IList<IBindingTypeConverter>`](https://learn.microsoft.com/dotnet/api/system.collections.generic.ilist-1) |
+
+### String and equality converters
+
+[Full description and examples](converters.md).
+
+Types: `ReactiveUI.Binding.EqualityTypeConverter`, `ReactiveUI.Binding.StringConverter`.
+
+#### `EqualityTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class EqualityTypeConverter` | Converts any value to a [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) that says whether it equals the conversion hint, using `Equals`. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `EqualityTypeConverter()` | Initializes a new instance of the EqualityTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+#### `StringConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class StringConverter` | Passes a [`string`](https://learn.microsoft.com/dotnet/api/system.string) through unchanged; a null or non-string value fails the conversion. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `StringConverter()` | Initializes a new instance of the StringConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The registry picks the highest value and, on a tie, the earliest registered converter. |
+| `TryConvertTyped(object? from, object? conversionHint, out object? result)` | Converts a boxed value. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `from`: The source value; null is accepted only where the converter can convert null; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint, such as a format string; out [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `result`: The converted value; null when the conversion fails or produces a null | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FromType { get; }` | Gets the source type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+| `ToType { get; }` | Gets the target type supported by this converter. | None. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) |
+
+## Mechanisms
+
+### Binding affinity
+
+[Full description and examples](mechanisms.md).
+
+Types: `ReactiveUI.Binding.BindingAffinity`, `ReactiveUI.Binding.Fallback.CommandBindingAffinityChecker`, `ReactiveUI.Binding.Fallback.ObservationAffinityChecker`.
+
+#### `BindingAffinity`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class BindingAffinity` | Common affinity scores shared by binding type converters, property observation factories, command binders, and the source generator's observation/command plugins. A higher value indicates a stronger match; zero means the candidate does not apply. `DefaultInternalTypeConverter`, `DefaultEvent`, `Explicit` and `ExactType` carry the same values as ReactiveUI's scores of those names; the platform-specific scores are this library's own. | None. | — |
+
+**Fields**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `readonly DefaultEvent` | The affinity for binding to a type's conventional default event. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32) |
+| `readonly DefaultInternalTypeConverter` | The affinity returned by the built-in value and string type converters. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32) |
+| `readonly EventEnabledControl` | The affinity for an event-enabled control command binding. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32) |
+| `readonly ExactType` | The affinity for a strong, exact-type match, such as IReactiveObject. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32) |
+| `readonly Explicit` | The affinity for an explicit or interface-based match, such as INotifyPropertyChanged or a named event. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32) |
+| `readonly Fallback` | The fallback affinity for the reflection-based POCO observer (lowest non-zero match). | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32) |
+| `readonly Kvo` | The affinity for an Apple KVO (`NSObject`) match. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32) |
+| `readonly WinFormsEvent` | The affinity for a WinForms event-based property observation match. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32) |
+| `readonly WinUiDependencyObject` | The affinity for a WinUI `DependencyObject` dependency-property match. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32) |
+| `readonly WpfDependencyObject` | The affinity for a WPF `DependencyObject` dependency-property match. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32) |
+
+#### `CommandBindingAffinityChecker`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class CommandBindingAffinityChecker` | Reports whether a registered [`ICreatesCommandBinding`](mechanisms.md) has a higher affinity for a control type than the mechanism the generator selected, so generated code can defer to it at runtime. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `HasHigherAffinityPlugin<T>(int generatedAffinity, bool hasEventTarget)` | Returns `true` if a registered [`ICreatesCommandBinding`](mechanisms.md) outranks `generatedAffinity`. | `T`: The control type being bound to; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `generatedAffinity`: The affinity of the source generator's selected plugin; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `hasEventTarget`: Whether the caller specifies a custom event target | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if a user plugin should override the generated binding; the registrations are read from the service locator on every call. |
+
+#### `ObservationAffinityChecker`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class ObservationAffinityChecker` | Finds a registered [`ICreatesObservableForProperty`](mechanisms.md) whose affinity for a type and property is higher than the affinity of the mechanism the generator selected, so generated code can defer to it at runtime. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `FindHigherAffinityPlugin(Type type, string propertyName, int generatedAffinity, bool beforeChanged)` | Finds the registered [`ICreatesObservableForProperty`](mechanisms.md) that outranks `generatedAffinity`. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `type`: The type being observed; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property being observed on that type; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `generatedAffinity`: The affinity of the source generator's selected plugin; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Whether before-change (PropertyChanging) observation is requested | [`ICreatesObservableForProperty?`](mechanisms.md): The highest-scoring registration whose score exceeds `generatedAffinity`, or `null` when none does. |
+| `HasHigherAffinityPlugin(Type type, string propertyName, int generatedAffinity, bool beforeChanged)` | Returns `true` if a registered [`ICreatesObservableForProperty`](mechanisms.md) outranks `generatedAffinity`. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `type`: The type being observed; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property being observed on that type; a plugin scores a type together with a property; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `generatedAffinity`: The affinity of the source generator's selected plugin; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Whether before-change (PropertyChanging) observation is requested | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if a user plugin should override the generated observation. |
+| `Refresh()` | Discards the cached registrations and scores so the next lookup reads the service locator again. | None. | — |
+
+### INotifyPropertyChanged and plain objects
+
+[Full description and examples](mechanisms.md).
+
+Types: `ReactiveUI.Binding.ObservableForProperty.INPCObservableForProperty`, `ReactiveUI.Binding.ObservableForProperty.POCOObservableForProperty`.
+
+#### `INPCObservableForProperty`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `class INPCObservableForProperty` | Observes properties of objects that implement [`INotifyPropertyChanged`](https://learn.microsoft.com/dotnet/api/system.componentmodel.inotifypropertychanged) or [`INotifyPropertyChanging`](https://learn.microsoft.com/dotnet/api/system.componentmodel.inotifypropertychanging). | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `INPCObservableForProperty()` | Initializes a new instance of the INPCObservableForProperty class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObject(Type type, string propertyName, bool beforeChanged)` | Returns the explicit affinity when the type implements [`INotifyPropertyChanging`](https://learn.microsoft.com/dotnet/api/system.componentmodel.inotifypropertychanging) (before-change) or [`INotifyPropertyChanged`](https://learn.microsoft.com/dotnet/api/system.componentmodel.inotifypropertychanged) (after-change); otherwise, zero. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `type`: The type being observed; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name being observed; not consulted; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Whether before-change notifications are requested | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): The affinity score, or zero when the type lacks the required interface. |
+| `GetNotificationForProperty(object sender, Expression expression, string propertyName, bool beforeChanged, bool suppressWarnings)` | Returns a sequence that emits when the sender raises a notification for the property, or a sequence that never emits when the sender implements neither interface. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `sender`: The object to observe; [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The expression identifying the property; an indexer matches the name followed by `[]`; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Whether to observe [`INotifyPropertyChanging`](https://learn.microsoft.com/dotnet/api/system.componentmodel.inotifypropertychanging); a sender that lacks it is observed through [`INotifyPropertyChanged`](https://learn.microsoft.com/dotnet/api/system.componentmodel.inotifypropertychanged); [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `suppressWarnings`: Not used | [`IObservable<IObservedChange<object, object?>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of observed changes. |
+
+#### `POCOObservableForProperty`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class POCOObservableForProperty` | Observes a property on a type that offers no change notification, at the lowest affinity. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `POCOObservableForProperty()` | Initializes a new instance of the POCOObservableForProperty class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObject(Type type, string propertyName, bool beforeChanged)` | Returns the fallback affinity for every type and property. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `type`: The type being observed; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name being observed; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Whether before-change notifications are requested; not consulted | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): The lowest positive affinity, so any other registered mechanism outranks it. |
+| `GetNotificationForProperty(object sender, Expression expression, string propertyName, bool beforeChanged, bool suppressWarnings)` | Returns a sequence that emits one observed change on subscribe and then stays silent. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `sender`: The object to observe; [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The expression identifying the property; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Whether before-change notifications are requested; not consulted; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `suppressWarnings`: `true` to skip the debug message written the first time a type and property are observed | [`IObservable<IObservedChange<object, object?>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits once and never completes. |
+
+### Custom observation providers
+
+[Full description and examples](mechanisms.md).
+
+Types: `ReactiveUI.Binding.CreatesObservableForPropertyMixins`, `ReactiveUI.Binding.ICreatesObservableForProperty`, `ReactiveUI.Binding.Observables.PluginObservationSource`, `ReactiveUI.Binding.Observables.PluginPropertyObservable<T>`.
+
+#### `CreatesObservableForPropertyMixins`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class CreatesObservableForPropertyMixins` | Overloads of [`ICreatesObservableForProperty`](mechanisms.md) members that default the before-change and warning flags to `false`. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ICreatesObservableForProperty.GetAffinityForObject(Type type, string propertyName)` | Returns the affinity for after-change observation of the specified property. | [`ICreatesObservableForProperty`](mechanisms.md) `factory` (receiver); [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `type`: The type being observed; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name being observed | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): The affinity score. Positive means supported. |
+| `ICreatesObservableForProperty.GetNotificationForProperty(object sender, Expression expression, string propertyName)` | Creates an observable that fires after the specified property changes, without suppressing warnings. | [`ICreatesObservableForProperty`](mechanisms.md) `factory` (receiver); [`object`](https://learn.microsoft.com/dotnet/api/system.object) `sender`: The object to observe; [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The expression identifying the property; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name | [`IObservable<IObservedChange<object, object?>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of observed changes. |
+| `ICreatesObservableForProperty.GetNotificationForProperty(object sender, Expression expression, string propertyName, bool beforeChanged)` | Creates an observable that fires when the specified property changes, without suppressing warnings. | [`ICreatesObservableForProperty`](mechanisms.md) `factory` (receiver); [`object`](https://learn.microsoft.com/dotnet/api/system.object) `sender`: The object to observe; [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The expression identifying the property; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Whether to observe before-change events | [`IObservable<IObservedChange<object, object?>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of observed changes. |
+
+#### `ICreatesObservableForProperty`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface ICreatesObservableForProperty` | Provides property change notifications for the types it supports; the registration with the highest affinity for a type and property is the one used. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObject(Type type, string propertyName, bool beforeChanged)` | Returns how well this implementation can observe a property of a type. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `type`: The type being observed; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name being observed; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Whether before-change (PropertyChanging) is requested | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive score when the property can be observed, where a higher score wins; zero or negative when it cannot. |
+| `GetNotificationForProperty(object sender, Expression expression, string propertyName, bool beforeChanged, bool suppressWarnings)` | Creates an observable that emits each time the specified property changes. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `sender`: The object to observe; [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The expression identifying the property; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Whether to observe before-change events; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `suppressWarnings`: Whether to suppress the warning written for a property that cannot notify | [`IObservable<IObservedChange<object, object?>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable of observed changes; callers read the current value from `sender` rather than from the emitted change. |
+
+#### `PluginObservationSource`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class PluginObservationSource` | Chooses between the observation the generator emitted for one link of a property chain and a registered [`ICreatesObservableForProperty`](mechanisms.md) that outranks the mechanism it was built from. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Choose<T>(object source, Expression expression, string propertyName, bool beforeChange, int generatedAffinity, Func<object, T?> getter, IObservable<T> generated)` | Returns the registration's observation of a property, or the generated one when none outranks it. | `T`: The type of the property value; [`object`](https://learn.microsoft.com/dotnet/api/system.object) `source`: The object the property is read from; [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The property as the generated code names it; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The name of the property being observed; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChange`: Whether before-change notifications are being observed; [`int`](https://learn.microsoft.com/dotnet/api/system.int32) `generatedAffinity`: The affinity of the mechanism the generator picked for this link; [`Func<object, T?>`](https://learn.microsoft.com/dotnet/api/system.func-2) `getter`: Reads the current property value from the source; [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `generated`: The observation the generator emitted for this link | [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): The generated observation when no registration outranks `generatedAffinity`; otherwise a [`PluginPropertyObservable<T>`](mechanisms.md) that does not filter consecutive equal values. |
+
+#### `PluginPropertyObservable<T>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class PluginPropertyObservable<T>` | Observes one property through a registered [`ICreatesObservableForProperty`](mechanisms.md) that outranks the mechanism the generator selected, reading the value through a generated accessor. | `T`: The type of the property value | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `PluginPropertyObservable(ICreatesObservableForProperty plugin, object source, Expression expression, string propertyName, Func<object, T?> getter, bool beforeChange, bool distinctUntilChanged)` | Initializes a new instance of the [`PluginPropertyObservable<T>`](mechanisms.md) class. | [`ICreatesObservableForProperty`](mechanisms.md) `plugin`: The registration that outranked the generated mechanism; [`object`](https://learn.microsoft.com/dotnet/api/system.object) `source`: The object the property is read from; [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The property as the call site named it; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The name of the property being observed; [`Func<object, T?>`](https://learn.microsoft.com/dotnet/api/system.func-2) `getter`: Reads the current property value from the source; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChange`: Whether before-change notifications are being observed; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `distinctUntilChanged`: Whether to suppress duplicate consecutive values | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Subscribe(IObserver<T> observer)` | Notifies the provider that an observer is to receive notifications. | [`IObserver<T>`](https://learn.microsoft.com/dotnet/api/system.iobserver-1) `observer`: The object that is to receive notifications | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A reference to an interface that allows observers to stop receiving notifications before the provider has finished sending them. |
+
+### Command binders
+
+[Full description and examples](mechanisms.md).
+
+Types: `ReactiveUI.Binding.CommandBinding.CommandBinderService`, `ReactiveUI.Binding.CommandBinding.CommandInvoker`, `ReactiveUI.Binding.ICreatesCommandBinding`.
+
+#### `CommandBinderService`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class CommandBinderService` | Service that resolves the best [`ICreatesCommandBinding`](mechanisms.md) for a given control type using affinity scoring. Follows the same resolution pattern as property observation via [`ICreatesObservableForProperty`](mechanisms.md). | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetBinder<T>(bool hasEventTarget)` | Gets the highest-affinity [`ICreatesCommandBinding`](mechanisms.md) registered for the specified control type. | `T`: The type of the control; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `hasEventTarget`: Whether the caller specifies a custom event target | [`ICreatesCommandBinding?`](mechanisms.md): The best binder; the first registered wins a tie. Null when every registered binder returns an affinity of zero or less. |
+
+#### `CommandInvoker`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class CommandInvoker` | Executes a command with each value a sequence produces. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Invoke<T>(IObservable<T> source, IObservable<ICommand?> commands)` | Executes whichever command the observed sequence of commands last produced. | `T`: The type of the value offered as the command parameter; [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source`: The sequence driving the executions; [`IObservable<ICommand?>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `commands`: The command to execute, as the observed property produces it | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, stops executing and stops observing the property. |
+| `Invoke<T>(IObservable<T> source, ICommand command)` | Executes one command with each value the sequence produces, skipping values the command refuses. | `T`: The type of the value offered as the command parameter; [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source`: The sequence driving the executions; [`ICommand`](https://learn.microsoft.com/dotnet/api/system.windows.input.icommand) `command`: The command to execute | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, stops executing the command. |
+
+#### `ICreatesCommandBinding`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface ICreatesCommandBinding` | Plugin interface for types that can bind an [`ICommand`](https://learn.microsoft.com/dotnet/api/system.windows.input.icommand) to a control. Implementations register with Splat and are resolved by affinity scoring. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BindCommandToObject<T>(ICommand? command, T? target, IObservable<object?> commandParameter)` | Binds an [`ICommand`](https://learn.microsoft.com/dotnet/api/system.windows.input.icommand) to a UI object using the default event. The default event is determined by the implementation (e.g., Click, TouchUpInside). | `T : class`: The type of the target object; [`ICommand?`](https://learn.microsoft.com/dotnet/api/system.windows.input.icommand) `command`: The command to bind. If `null`, no binding is created; `T?` `target`: The target object, usually a UI control; [`IObservable<object?>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `commandParameter`: An observable that provides the command parameter value | [`IDisposable?`](https://learn.microsoft.com/dotnet/api/system.idisposable): An [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable) that disconnects the binding when disposed, or `null` if no binding was created. |
+| `BindCommandToObject<T, TEventArgs>(ICommand? command, T? target, IObservable<object?> commandParameter, string eventName)` | Binds an [`ICommand`](https://learn.microsoft.com/dotnet/api/system.windows.input.icommand) to a UI object to a specific named event. | `T : class`: The type of the target object; `TEventArgs`: The event argument type; [`ICommand?`](https://learn.microsoft.com/dotnet/api/system.windows.input.icommand) `command`: The command to bind. If `null`, no binding is created; `T?` `target`: The target object, usually a UI control; [`IObservable<object?>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `commandParameter`: An observable that provides the command parameter value; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `eventName`: The event to bind to | [`IDisposable?`](https://learn.microsoft.com/dotnet/api/system.idisposable): An [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable) that disconnects the binding when disposed, or `null` if no binding was created. |
+| `BindCommandToObject<T, TEventArgs>(ICommand? command, T? target, IObservable<object?> commandParameter, Action<EventHandler<TEventArgs>> addHandler, Action<EventHandler<TEventArgs>> removeHandler)` | Binds a command to a specific event on a target object using explicit add/remove handler delegates. This overload is fully AOT-compatible as it avoids reflection-based event lookup. | `T : class`: The type of the target object; `TEventArgs : EventArgs`: The event arguments type; [`ICommand?`](https://learn.microsoft.com/dotnet/api/system.windows.input.icommand) `command`: The command to bind. If `null`, no binding is created; `T?` `target`: The target object; [`IObservable<object?>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `commandParameter`: An observable that supplies command parameter values; [`Action<EventHandler<TEventArgs>>`](https://learn.microsoft.com/dotnet/api/system.action-1) `addHandler`: Adds the handler to the target event; [`Action<EventHandler<TEventArgs>>`](https://learn.microsoft.com/dotnet/api/system.action-1) `removeHandler`: Removes the handler from the target event | [`IDisposable?`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that unbinds the command. |
+| `GetAffinityForObject<T>(bool hasEventTarget)` | Returns a positive integer when this implementation supports binding a command to an object of the specified type. If the binding is not supported, the method returns a non-positive integer. In cases where multiple implementations return positive values, the one with the highest value wins. | `T`: The type of the control to bind to; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `hasEventTarget`: Whether the caller specifies a custom event target | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive integer if binding is supported, or zero/negative if not. |
+
+### Observables
+
+[Full description and examples](mechanisms.md).
+
+Types: `ReactiveUI.Binding.Observables.AppliedChangeObservable`, `ReactiveUI.Binding.Observables.CombineLatestObservable`, `ReactiveUI.Binding.Observables.EventObservable<T>`, `ReactiveUI.Binding.Observables.NotifyPropertyChangedObservable`, `ReactiveUI.Binding.Observables.PropertyChangingObservable<T>`, `ReactiveUI.Binding.Observables.PropertyObservable<T>`, `ReactiveUI.Binding.Observables.UnchangingPropertyObservable<T>`.
+
+#### `AppliedChangeObservable`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class AppliedChangeObservable` | The changes a two-way binding actually wrote, handed to whoever subscribes to the binding. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `AppliedChangeObservable()` | Initializes a new instance of the AppliedChangeObservable class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `OnNext(BindingChange value)` | Reports a change the binding has written. | [`BindingChange`](bindings.md) `value`: The change that was written | — |
+| `Subscribe(IObserver<BindingChange> observer)` | Notifies the provider that an observer is to receive notifications. | [`IObserver<BindingChange>`](https://learn.microsoft.com/dotnet/api/system.iobserver-1) `observer`: The object that is to receive notifications | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A reference to an interface that allows observers to stop receiving notifications before the provider has finished sending them. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `HasObservers { get; }` | Gets a value indicating whether at least one observer is subscribed. | None. | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) |
+
+#### `CombineLatestObservable`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class CombineLatestObservable` | Creates an observable that combines the latest value of each of two to sixteen sources. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Create<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TResult>(IObservable<T1> source1, IObservable<T2> source2, IObservable<T3> source3, IObservable<T4> source4, IObservable<T5> source5, IObservable<T6> source6, IObservable<T7> source7, IObservable<T8> source8, IObservable<T9> source9, IObservable<T10> source10, IObservable<T11> source11, IObservable<T12> source12, IObservable<T13> source13, IObservable<T14> source14, IObservable<T15> source15, IObservable<T16> source16, Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TResult> resultSelector)` | Combines the latest values from sixteen observables using a result selector. Available for 2 to 16 repeated arguments; the largest form is listed. | `T1`: Source element type 1; `T2`: Source element type 2; `T3`: Source element type 3; `T4`: Source element type 4; `T5`: Source element type 5; `T6`: Source element type 6; `T7`: Source element type 7; `T8`: Source element type 8; `T9`: Source element type 9; `T10`: Source element type 10; `T11`: Source element type 11; `T12`: Source element type 12; `T13`: Source element type 13; `T14`: Source element type 14; `T15`: Source element type 15; `T16`: Source element type 16; `TResult`: The result element type; [`IObservable<T1>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source1`: Source observable 1; [`IObservable<T2>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source2`: Source observable 2; [`IObservable<T3>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source3`: Source observable 3; [`IObservable<T4>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source4`: Source observable 4; [`IObservable<T5>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source5`: Source observable 5; [`IObservable<T6>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source6`: Source observable 6; [`IObservable<T7>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source7`: Source observable 7; [`IObservable<T8>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source8`: Source observable 8; [`IObservable<T9>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source9`: Source observable 9; [`IObservable<T10>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source10`: Source observable 10; [`IObservable<T11>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source11`: Source observable 11; [`IObservable<T12>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source12`: Source observable 12; [`IObservable<T13>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source13`: Source observable 13; [`IObservable<T14>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source14`: Source observable 14; [`IObservable<T15>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source15`: Source observable 15; [`IObservable<T16>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source16`: Source observable 16; [`Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TResult>`](https://learn.microsoft.com/dotnet/api/system.func-17) `resultSelector`: The function to combine the latest values | [`IObservable<TResult>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits once every source has produced a value, then again on each later value from any source. |
+
+#### `EventObservable<T>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class EventObservable<T>` | Emits a value on subscribe, then again each time an [`EventHandler`](https://learn.microsoft.com/dotnet/api/system.eventhandler) event is raised. | `T`: The type of the property value | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `EventObservable(Action<EventHandler> addHandler, Action<EventHandler> removeHandler, Func<T> getter, bool distinctUntilChanged)` | Initializes a new instance of the [`EventObservable<T>`](mechanisms.md) class. | [`Action<EventHandler>`](https://learn.microsoft.com/dotnet/api/system.action-1) `addHandler`: A delegate that subscribes an [`EventHandler`](https://learn.microsoft.com/dotnet/api/system.eventhandler) to the property change event; [`Action<EventHandler>`](https://learn.microsoft.com/dotnet/api/system.action-1) `removeHandler`: A delegate that unsubscribes an [`EventHandler`](https://learn.microsoft.com/dotnet/api/system.eventhandler) from the property change event; [`Func<T>`](https://learn.microsoft.com/dotnet/api/system.func-1) `getter`: A delegate that reads the current property value; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `distinctUntilChanged`: Whether to suppress duplicate consecutive values | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Subscribe(IObserver<T> observer)` | Notifies the provider that an observer is to receive notifications. | [`IObserver<T>`](https://learn.microsoft.com/dotnet/api/system.iobserver-1) `observer`: The object that is to receive notifications | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A reference to an interface that allows observers to stop receiving notifications before the provider has finished sending them. |
+
+#### `NotifyPropertyChangedObservable`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class NotifyPropertyChangedObservable` | Emits an observed change each time the sender raises a notification for one property. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `NotifyPropertyChangedObservable(object sender, Expression expression, string expectedName, bool beforeChanged)` | Initializes a new instance of the [`NotifyPropertyChangedObservable`](mechanisms.md) class. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `sender`: The source object raising the notifications; [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The expression surfaced on the emitted observed change; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `expectedName`: The property name to match, ending in `[]` for an indexer; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Whether to observe before-change notifications | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Subscribe(IObserver<IObservedChange<object, object?>> observer)` | Notifies the provider that an observer is to receive notifications. | [`IObserver<IObservedChange<object, object?>>`](https://learn.microsoft.com/dotnet/api/system.iobserver-1) `observer`: The object that is to receive notifications | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A reference to an interface that allows observers to stop receiving notifications before the provider has finished sending them. |
+
+#### `PropertyChangingObservable<T>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class PropertyChangingObservable<T>` | Emits the current value of a property on subscribe, then its value as it stands before each change that an [`INotifyPropertyChanging`](https://learn.microsoft.com/dotnet/api/system.componentmodel.inotifypropertychanging) source announces. | `T`: The type of the property value | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `PropertyChangingObservable(INotifyPropertyChanging source, string propertyName, Func<INotifyPropertyChanging, T?> getter)` | Initializes a new instance of the [`PropertyChangingObservable<T>`](mechanisms.md) class. | [`INotifyPropertyChanging`](https://learn.microsoft.com/dotnet/api/system.componentmodel.inotifypropertychanging) `source`: The object implementing [`INotifyPropertyChanging`](https://learn.microsoft.com/dotnet/api/system.componentmodel.inotifypropertychanging); [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name to observe; [`Func<INotifyPropertyChanging, T?>`](https://learn.microsoft.com/dotnet/api/system.func-2) `getter`: A delegate that reads the property value from the source | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Subscribe(IObserver<T> observer)` | Notifies the provider that an observer is to receive notifications. | [`IObserver<T>`](https://learn.microsoft.com/dotnet/api/system.iobserver-1) `observer`: The object that is to receive notifications | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A reference to an interface that allows observers to stop receiving notifications before the provider has finished sending them. |
+
+#### `PropertyObservable<T>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class PropertyObservable<T>` | Emits a property's value on subscribe, then its new value after each change the source announces. | `T`: The type of the property value | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `PropertyObservable(INotifyPropertyChanged source, string propertyName, Func<INotifyPropertyChanged, T?> getter, bool distinctUntilChanged)` | Initializes a new instance of the [`PropertyObservable<T>`](mechanisms.md) class. | [`INotifyPropertyChanged`](https://learn.microsoft.com/dotnet/api/system.componentmodel.inotifypropertychanged) `source`: The object implementing [`INotifyPropertyChanged`](https://learn.microsoft.com/dotnet/api/system.componentmodel.inotifypropertychanged); [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name to observe; [`Func<INotifyPropertyChanged, T?>`](https://learn.microsoft.com/dotnet/api/system.func-2) `getter`: A delegate that reads the property value from the source; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `distinctUntilChanged`: Whether to suppress duplicate consecutive values | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Subscribe(IObserver<T> observer)` | Notifies the provider that an observer is to receive notifications. | [`IObserver<T>`](https://learn.microsoft.com/dotnet/api/system.iobserver-1) `observer`: The object that is to receive notifications | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A reference to an interface that allows observers to stop receiving notifications before the provider has finished sending them. |
+
+#### `UnchangingPropertyObservable<T>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class UnchangingPropertyObservable<T>` | Observes a property that has no change notification: its value, once, and then silence. | `T`: The type of the property value | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `UnchangingPropertyObservable(T value)` | Initializes a new instance of the [`UnchangingPropertyObservable<T>`](mechanisms.md) class. | `T` `value`: The property's current value, which is also its final one | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Subscribe(IObserver<T> observer)` | Notifies the provider that an observer is to receive notifications. | [`IObserver<T>`](https://learn.microsoft.com/dotnet/api/system.iobserver-1) `observer`: The object that is to receive notifications | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A reference to an interface that allows observers to stop receiving notifications before the provider has finished sending them. |
+
+## Views
+
+### Views
+
+[Full description and examples](views.md).
+
+Types: `ReactiveUI.Binding.IActivatableView`, `ReactiveUI.Binding.IViewFor`, `ReactiveUI.Binding.IViewFor<T>`.
+
+#### `IActivatableView`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IActivatableView` | Marker interface that every [`IViewFor`](views.md) implements; it declares no members. | None. | — |
+
+#### `IViewFor`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IViewFor` | Non-generic interface for views that display a view model. | None. | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ViewModel { get; set; }` | Gets or sets the view model displayed by the view. | None. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) |
+
+#### `IViewFor<T>`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IViewFor<T>` | Generic interface for views that display a specific view model type. | `T : class`: The type of the view model | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ViewModel { get; set; }` | Gets or sets the view model displayed by the view. | None. | `T?` |
+
+### View locators
+
+[Full description and examples](views.md).
+
+Types: `ReactiveUI.Binding.DefaultViewLocator`, `ReactiveUI.Binding.IViewLocator`, `ReactiveUI.Binding.ViewLocator`, `ReactiveUI.Binding.ViewLocatorMixins`, `ReactiveUI.Binding.ViewLocatorNotFoundException`.
+
+#### `DefaultViewLocator`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class DefaultViewLocator` | Default implementation of [`IViewLocator`](views.md) that resolves views for view models using a three-tier resolution strategy: source-generated AOT-safe dispatch, explicit runtime mappings, and service locator fallback. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `DefaultViewLocator()` | Initializes a new instance of the DefaultViewLocator class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ResolveView(object? viewModel, string? contract)` | Resolves a view for the view model using its runtime type. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `viewModel`: The view model instance to resolve a view for; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `contract`: The contract to resolve under, or null for the default view | [`IViewFor?`](views.md): The resolved view, or `null` if no view is found. |
+| `ResolveView<TViewModel>(TViewModel viewModel, string? contract)` | Resolves a view for the view model using its compile-time type, without reflection over the view model's runtime type. | `TViewModel : class`: The type of the view model; `TViewModel` `viewModel`: The view model instance to resolve a view for; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `contract`: The contract to resolve under, or null for the default view | [`IViewFor?`](views.md): The resolved view, or `null` if no view is found. |
+| `static SetGeneratedViewDispatch(Func<object, string, IViewFor?> dispatch)` | Adds a source-generated view dispatch function. Called by `__ReactiveUIGeneratedBindings`: from a module initializer in a C# 9 or newer project, and from its static constructor in an older one. Each assembly that contains views registers its own. | [`Func<object, string, IViewFor?>`](https://learn.microsoft.com/dotnet/api/system.func-3) `dispatch`: The dispatch function that resolves views by type-switching on the view model instance | — |
+
+#### `IViewLocator`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IViewLocator` | Resolves views for view models. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ResolveView(object? viewModel, string? contract)` | Resolves a view for the view model using its runtime type. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `viewModel`: The view model instance to resolve a view for; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `contract`: The contract to resolve under, or null for the default view | [`IViewFor?`](views.md): The resolved view, or `null` if no view is found. |
+| `ResolveView<TViewModel>(TViewModel viewModel, string? contract)` | Resolves a view for the view model using its compile-time type, without reflection over the view model's runtime type. | `TViewModel : class`: The type of the view model; `TViewModel` `viewModel`: The view model instance to resolve a view for; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `contract`: The contract to resolve under, or null for the default view | [`IViewFor?`](views.md): The resolved view, or `null` if no view is found. |
+
+#### `ViewLocator`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class ViewLocator` | Static accessor for the current [`IViewLocator`](views.md) instance. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetCurrent()` | Gets the current [`IViewLocator`](views.md) from the service locator. | None. | [`IViewLocator`](views.md): The current [`IViewLocator`](views.md) instance. |
+
+#### `ViewLocatorMixins`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class ViewLocatorMixins` | Convenience overloads for [`IViewLocator`](views.md) that supply the default (null) contract. Provided as overloads rather than optional parameters so the interface stays free of optional parameters. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `IViewLocator.ResolveView(object? viewModel)` | Resolves a view for the specified view model instance using the default contract. | [`IViewLocator`](views.md) `locator` (receiver); [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `viewModel`: The view model instance to resolve a view for | [`IViewFor?`](views.md): The resolved view, or `null` if no view is found. |
+| `IViewLocator.ResolveView<TViewModel>(TViewModel viewModel)` | Resolves a view for the specified view model type using the default contract. | `TViewModel : class`: The type of the view model; [`IViewLocator`](views.md) `locator` (receiver); `TViewModel` `viewModel`: The view model instance to resolve a view for | [`IViewFor?`](views.md): The resolved view, or `null` if no view is found. |
+
+#### `ViewLocatorNotFoundException`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `class ViewLocatorNotFoundException : Exception` | Exception thrown when a view locator is not registered with the dependency resolver. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ViewLocatorNotFoundException()` | Initializes a new instance of the [`ViewLocatorNotFoundException`](views.md) class with a message naming the builder calls that register the default locator. | None. | — |
+| `ViewLocatorNotFoundException(string message)` | Initializes a new instance of the [`ViewLocatorNotFoundException`](views.md) class with a specified error message. | [`string`](https://learn.microsoft.com/dotnet/api/system.string) `message`: The message that describes the error | — |
+| `ViewLocatorNotFoundException(string message, Exception innerException)` | Initializes a new instance of the [`ViewLocatorNotFoundException`](views.md) class with a specified error message and a reference to the inner exception. | [`string`](https://learn.microsoft.com/dotnet/api/system.string) `message`: The message that describes the error; [`Exception`](https://learn.microsoft.com/dotnet/api/system.exception) `innerException`: The exception that is the cause of the current exception | — |
+
+### View mapping
+
+[Full description and examples](views.md).
+
+Types: `ReactiveUI.Binding.DefaultViewLocator`, `ReactiveUI.Binding.ExcludeFromViewRegistrationAttribute`, `ReactiveUI.Binding.SingleInstanceViewAttribute`, `ReactiveUI.Binding.ViewContractAttribute`, `ReactiveUI.Binding.ViewMappingBuilder`.
+
+#### `DefaultViewLocator`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `CreateMappingBuilder()` | Creates a new [`ViewMappingBuilder`](views.md) for fluent registration of view-to-view-model mappings. | None. | [`ViewMappingBuilder`](views.md): A new [`ViewMappingBuilder`](views.md) targeting this locator instance. |
+| `Map<TViewModel, TView>()` | Registers an explicit view mapping for a view model type. | `TViewModel : class`: The view model type; `TView : IViewFor, new()`: The view type. Must implement [`IViewFor`](views.md) | — |
+| `Map<TViewModel>(Func<IViewFor> factory)` | Registers an explicit view mapping with a custom factory for a view model type. | `TViewModel : class`: The view model type; [`Func<IViewFor>`](https://learn.microsoft.com/dotnet/api/system.func-1) `factory`: A factory function that creates the view | — |
+| `Map<TViewModel, TView>(string? contract)` | Registers an explicit view mapping for a view model type. | `TViewModel : class`: The view model type; `TView : IViewFor, new()`: The view type. Must implement [`IViewFor`](views.md); [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `contract`: A contract string for named registrations | — |
+| `Map<TViewModel>(Func<IViewFor> factory, string? contract)` | Registers an explicit view mapping with a custom factory for a view model type. | `TViewModel : class`: The view model type; [`Func<IViewFor>`](https://learn.microsoft.com/dotnet/api/system.func-1) `factory`: A factory function that creates the view; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `contract`: A contract string for named registrations | — |
+| `Unmap<TViewModel>()` | Removes an explicit view mapping for a view model type. | `TViewModel : class`: The view model type | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if the mapping was removed; otherwise, `false`. |
+| `Unmap<TViewModel>(string? contract)` | Removes an explicit view mapping for a view model type. | `TViewModel : class`: The view model type; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `contract`: A contract string for named registrations | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if the mapping was removed; otherwise, `false`. |
+
+#### `ExcludeFromViewRegistrationAttribute`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ExcludeFromViewRegistrationAttribute : Attribute` | Leaves a view class out of the view dispatch the source generator builds from [`IViewFor<T>`](views.md) implementations. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ExcludeFromViewRegistrationAttribute()` | Initializes a new instance of the ExcludeFromViewRegistrationAttribute class. | None. | — |
+
+#### `SingleInstanceViewAttribute`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class SingleInstanceViewAttribute : Attribute` | Indicates that this View should be constructed once and then reused every time its ViewModel's View is resolved. The source generator will emit a cached singleton pattern instead of creating a new instance per resolution. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `SingleInstanceViewAttribute()` | Initializes a new instance of the SingleInstanceViewAttribute class. | None. | — |
+
+#### `ViewContractAttribute`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ViewContractAttribute : Attribute` | Registers an [`IViewFor<T>`](views.md) view in the generated view dispatch under a contract string, so one view model can have a different view per contract. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ViewContractAttribute(string contract)` | Registers an [`IViewFor<T>`](views.md) view in the generated view dispatch under a contract string, so one view model can have a different view per contract. | [`string`](https://learn.microsoft.com/dotnet/api/system.string) `contract`: The contract value for view resolution | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Contract { get; }` | Gets the contract to use when resolving the view. | None. | [`string`](https://learn.microsoft.com/dotnet/api/system.string) |
+
+#### `ViewMappingBuilder`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ViewMappingBuilder` | Fluent builder for registering view-to-view-model mappings on a [`DefaultViewLocator`](views.md). | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Map<TViewModel, TView>()` | Maps a view model type to a view type constructed with its parameterless constructor, replacing an existing mapping for the same view model type. | `TViewModel : class`: The view model type; `TView : IViewFor, new()`: The view type. Must have a parameterless constructor | [`ViewMappingBuilder`](views.md): This builder for chaining. |
+| `Map<TViewModel>(Func<IViewFor> factory)` | Maps a view model type to a view created by a factory, replacing an existing mapping for the same view model type. | `TViewModel : class`: The view model type; [`Func<IViewFor>`](https://learn.microsoft.com/dotnet/api/system.func-1) `factory`: A factory function that creates the view | [`ViewMappingBuilder`](views.md): This builder for chaining. |
+| `Map<TViewModel, TView>(string? contract)` | Maps a view model type and contract to a view type constructed with its parameterless constructor, replacing an existing mapping for the same pair. | `TViewModel : class`: The view model type; `TView : IViewFor, new()`: The view type. Must have a parameterless constructor; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `contract`: The contract the mapping is registered under; null registers the default mapping | [`ViewMappingBuilder`](views.md): This builder for chaining. |
+| `Map<TViewModel>(Func<IViewFor> factory, string? contract)` | Maps a view model type and contract to a view created by a factory, replacing an existing mapping for the same pair. | `TViewModel : class`: The view model type; [`Func<IViewFor>`](https://learn.microsoft.com/dotnet/api/system.func-1) `factory`: A factory function that creates the view; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `contract`: The contract the mapping is registered under; null registers the default mapping | [`ViewMappingBuilder`](views.md): This builder for chaining. |
+
+## Threading
+
+### Schedulers
+
+[Full description and examples](threading.md).
+
+Types: `ReactiveUI.Binding.BindingSchedulers`.
+
+#### `BindingSchedulers`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class BindingSchedulers` | Where a binding delivers its writes to the view. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ObserveOnSequencer<T>(IObservable<T> source, ISequencer scheduler)` | Routes an observable onto a sequencer, delivering only the latest value that is waiting on it. | `T`: The type of the observed values; [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source`: The observable feeding a write; `ISequencer` `scheduler`: The sequencer every delivery waits on | [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): The source, observed on the sequencer with a newer value replacing one that has not been delivered. |
+| `ObserveOnViewThread<T>(IObservable<T> source, object? target)` | Routes an observable onto the thread that owns the object being written to. | `T`: The type of the observed values; [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source`: The observable feeding a write; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `target`: The object the write lands on | [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): The source itself when `target` is null or no registered invoker claims it; otherwise the source routed onto its thread. |
+| `ObserveOnViewThread<T>(IObservable<T> source, object? target, IViewThreadInvoker fallback)` | Routes an observable onto the thread that owns the object being written to, falling back to a known invoker. | `T`: The type of the observed values; [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source`: The observable feeding a write; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `target`: The object the write lands on; [`IViewThreadInvoker`](threading.md) `fallback`: The invoker for the object's platform, used when no registered invoker claims it | [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): The source itself when `target` is null; otherwise the source routed onto its thread. |
+| `UseSynchronizationContext(SynchronizationContext? context)` | Delivers writes from another thread through a synchronization context. | [`SynchronizationContext?`](https://learn.microsoft.com/dotnet/api/system.threading.synchronizationcontext) `context`: The context owning the view, or null to use the view's own dispatcher | — |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `MainThread { get; set; }` | Gets or sets the sequencer a write from another thread is delivered on, or null to use the view's own dispatcher. | None. | `ISequencer?` |
+
+### View thread invokers
+
+[Full description and examples](threading.md).
+
+Types: `ReactiveUI.Binding.IViewThreadInvoker`, `ReactiveUI.Binding.ViewThreadInvokers`.
+
+#### `IViewThreadInvoker`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IViewThreadInvoker` | Runs a binding's write on the thread that owns the object it lands on, through the platform's own dispatcher. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `CheckAccess(object target)` | Determines whether the calling thread may write to `target` directly. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: An object this invoker claims | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` on the owning thread, or when the object has no owning thread; otherwise `false`. |
+| `Claims(object target)` | Determines whether this invoker handles `target`. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: The object a binding writes to | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` when the object belongs to this invoker's platform; otherwise `false`. |
+| `Post(object target, Action<object?> callback, object? state)` | Queues a callback on the thread that owns `target`. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: An object this invoker claims; [`Action<object?>`](https://learn.microsoft.com/dotnet/api/system.action-1) `callback`: The callback to run; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `state`: The value handed to `callback` | — |
+
+#### `ViewThreadInvokers`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class ViewThreadInvokers` | Finds the registered invoker for the object a binding writes to. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ForTarget(object? target)` | Finds the first registered invoker that claims `target`. | [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `target`: The object a binding is about to write to | [`IViewThreadInvoker?`](threading.md): The invoker, or null when `target` is null or nothing claims it. |
+| `Refresh()` | Re-reads the registered invokers, for a host that registers one after its first binding. | None. | — |
+
+## Setup
+
+### Builder
+
+[Full description and examples](setup.md).
+
+Types: `ReactiveUI.Binding.Builder.IReactiveUIBindingBuilder`, `ReactiveUI.Binding.Builder.IReactiveUIBindingInstance`, `ReactiveUI.Binding.Builder.ReactiveUIBindingBuilder`, `ReactiveUI.Binding.Builder.ReactiveUIBindingModule`, `ReactiveUI.Binding.Builder.RxBindingBuilder`, `ReactiveUI.Binding.Builder.RxBindingBuilderMixins`, `ReactiveUI.Binding.Mixins.BuilderMixins`.
+
+#### `IReactiveUIBindingBuilder`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IReactiveUIBindingBuilder` | Fluent builder that configures ReactiveUI.Binding services, converters, and platform modules before building an application instance. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BuildApp()` | Builds the application, publishes the converter service and marks ReactiveUI.Binding initialized. | None. | [`IReactiveUIBindingInstance`](setup.md): The configured application instance. |
+| `ConfigureViewLocator(Action<ViewMappingBuilder> configure)` | Registers a default view locator holding the explicit view-to-view-model mappings. | [`Action<ViewMappingBuilder>`](https://learn.microsoft.com/dotnet/api/system.action-1) `configure`: An action that receives a [`ViewMappingBuilder`](views.md) for registering mappings | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `WithCommandBinder(ICreatesCommandBinding binder)` | Registers a custom command binder for binding [`ICommand`](https://learn.microsoft.com/dotnet/api/system.windows.input.icommand) instances to UI controls. | [`ICreatesCommandBinding`](mechanisms.md) `binder`: The command binder instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `WithConverter(IBindingTypeConverter converter)` | Registers a typed binding converter. | [`IBindingTypeConverter`](converters.md) `converter`: The converter instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `WithCoreServices()` | Registers the core ReactiveUI.Binding services (INPC/POCO observation, default converters, default view locator). Hides `WithCoreServices` to return [`IReactiveUIBindingBuilder`](setup.md) for fluent chaining. | None. | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `WithFallbackConverter(IBindingFallbackConverter converter)` | Registers a fallback binding converter. | [`IBindingFallbackConverter`](converters.md) `converter`: The fallback converter instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `WithPlatformModule<T>(T module)` | Registers a platform-specific module with the builder. | `T : IModule`: The type of the platform module. Must implement `IModule`; `T` `module`: The platform module instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `WithRegistration(Action<IMutableDependencyResolver> configureAction)` | Runs a registration action against the mutable dependency resolver. | [`Action<IMutableDependencyResolver>`](https://learn.microsoft.com/dotnet/api/system.action-1) `configureAction`: An action that receives the mutable dependency resolver | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `WithSetMethodConverter(ISetMethodBindingConverter converter)` | Registers a set-method binding converter. | [`ISetMethodBindingConverter`](converters.md) `converter`: The set-method converter instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+
+#### `IReactiveUIBindingInstance`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `interface IReactiveUIBindingInstance` | Represents a configured ReactiveUI.Binding application instance. | None. | — |
+
+#### `ReactiveUIBindingBuilder`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ReactiveUIBindingBuilder : AppBuilder` | Configures ReactiveUI.Binding services, converters and platform modules on a Splat `AppBuilder`. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ReactiveUIBindingBuilder(IMutableDependencyResolver resolver, IReadonlyDependencyResolver? current)` | Initializes a new instance of the [`ReactiveUIBindingBuilder`](setup.md) class, initializing Splat on the resolver and registering `ConverterService` with it. | `IMutableDependencyResolver` `resolver`: The dependency resolver to configure; `IReadonlyDependencyResolver?` `current`: The resolver that reads the configured services; may be null | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BuildApp()` | Builds the application, publishes `ConverterService` through [`BindingConverters`](converters.md) and marks ReactiveUI.Binding initialized. | None. | [`IReactiveUIBindingInstance`](setup.md): The configured application instance. |
+| `ConfigureViewLocator(Action<ViewMappingBuilder> configure)` | Creates a [`DefaultViewLocator`](views.md) holding the explicit mappings and registers it as the [`IViewLocator`](views.md). | [`Action<ViewMappingBuilder>`](https://learn.microsoft.com/dotnet/api/system.action-1) `configure`: An action that receives a [`ViewMappingBuilder`](views.md) for registering mappings | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `WithCommandBinder(ICreatesCommandBinding binder)` | Registers a custom command binder for binding commands to UI controls. | [`ICreatesCommandBinding`](mechanisms.md) `binder`: The command binder instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `WithConverter(IBindingTypeConverter converter)` | Registers a typed binding converter. | [`IBindingTypeConverter`](converters.md) `converter`: The converter instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `override WithCoreServices()` | Registers the default converters, the INPC and POCO observation services and the default view locator; calling it again registers nothing more. | None. | `IAppBuilder`: The builder instance for chaining. |
+| `WithFallbackConverter(IBindingFallbackConverter converter)` | Registers a fallback binding converter. | [`IBindingFallbackConverter`](converters.md) `converter`: The fallback converter instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `WithPlatformModule<T>(T module)` | Registers a platform-specific module with the builder. | `T : IModule`: The type of the platform module. Must implement `IModule`; `T` `module`: The platform module instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `WithRegistration(Action<IMutableDependencyResolver> configureAction)` | Runs a registration action against the mutable dependency resolver immediately. | [`Action<IMutableDependencyResolver>`](https://learn.microsoft.com/dotnet/api/system.action-1) `configureAction`: An action that receives the mutable dependency resolver | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `WithSetMethodConverter(ISetMethodBindingConverter converter)` | Registers a set-method binding converter. | [`ISetMethodBindingConverter`](converters.md) `converter`: The set-method converter instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+
+**Properties**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ConverterService { get; }` | Gets the converter service used for binding type conversions. | None. | [`ConverterService`](converters.md) |
+
+#### `ReactiveUIBindingModule`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ReactiveUIBindingModule` | Registers the [`ICreatesObservableForProperty`](mechanisms.md) implementations for INotifyPropertyChanged and plain object properties. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ReactiveUIBindingModule()` | Initializes a new instance of the ReactiveUIBindingModule class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Configure(IMutableDependencyResolver resolver)` | Registers the INPC and POCO property observation services with the resolver. | `IMutableDependencyResolver` `resolver`: The dependency resolver to configure | — |
+
+#### `RxBindingBuilder`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class RxBindingBuilder` | Static factory for creating [`ReactiveUIBindingBuilder`](setup.md) instances. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `CreateReactiveUIBindingBuilder()` | Creates a new [`ReactiveUIBindingBuilder`](setup.md) using the current Splat locator. | None. | [`ReactiveUIBindingBuilder`](setup.md): A new builder instance. |
+| `EnsureInitialized()` | Returns when a builder's `BuildApp()` has completed, and throws otherwise. | None. | — |
+
+#### `RxBindingBuilderMixins`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class RxBindingBuilderMixins` | Resolver-scoped entry points for creating [`ReactiveUIBindingBuilder`](setup.md) instances. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `IMutableDependencyResolver.CreateReactiveUIBindingBuilder()` | Creates a new [`ReactiveUIBindingBuilder`](setup.md) that registers into the specified resolver. | `IMutableDependencyResolver` `resolver` (receiver) | [`ReactiveUIBindingBuilder`](setup.md): A new builder instance that reads services from the resolver when it is also an `IReadonlyDependencyResolver`, and from the current locator otherwise. |
+
+#### `BuilderMixins`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class BuilderMixins` | Extension methods that bridge `IAppBuilder` to [`IReactiveUIBindingBuilder`](setup.md) for fluent chaining. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `IAppBuilder.BuildApp()` | Builds the ReactiveUI.Binding application from an `IAppBuilder`. | `IAppBuilder` `appBuilder` (receiver): The app builder instance | [`IReactiveUIBindingInstance`](setup.md): The configured application instance. |
+| `IAppBuilder.ConfigureViewLocator(Action<ViewMappingBuilder> configure)` | Configures the default view locator with explicit view-to-view-model mappings from an `IAppBuilder`. | `IAppBuilder` `appBuilder` (receiver): The app builder instance; [`Action<ViewMappingBuilder>`](https://learn.microsoft.com/dotnet/api/system.action-1) `configure`: An action that receives a [`ViewMappingBuilder`](views.md) for registering mappings | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `IAppBuilder.WithConverter(IBindingTypeConverter converter)` | Registers a typed binding converter from an `IAppBuilder`. | `IAppBuilder` `appBuilder` (receiver): The app builder instance; [`IBindingTypeConverter`](converters.md) `converter`: The converter instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `IAppBuilder.WithFallbackConverter(IBindingFallbackConverter converter)` | Registers a fallback binding converter from an `IAppBuilder`. | `IAppBuilder` `appBuilder` (receiver): The app builder instance; [`IBindingFallbackConverter`](converters.md) `converter`: The fallback converter instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `IAppBuilder.WithPlatformModule<T>(T module)` | Registers a platform-specific module from an `IAppBuilder`. | `T : IModule`: The type of the platform module; `IAppBuilder` `appBuilder` (receiver): The app builder instance; `T` `module`: The platform module instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `IAppBuilder.WithRegistration(Action<IMutableDependencyResolver> configureAction)` | Adds a custom registration action from an `IAppBuilder`. | `IAppBuilder` `appBuilder` (receiver): The app builder instance; [`Action<IMutableDependencyResolver>`](https://learn.microsoft.com/dotnet/api/system.action-1) `configureAction`: An action that receives the mutable dependency resolver | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `IAppBuilder.WithSetMethodConverter(ISetMethodBindingConverter converter)` | Registers a set-method binding converter from an `IAppBuilder`. | `IAppBuilder` `appBuilder` (receiver): The app builder instance; [`ISetMethodBindingConverter`](converters.md) `converter`: The set-method converter instance to register | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+
+## Unsafe and runtime
+
+### Unsafe overloads
+
+[Full description and examples](unsafe.md).
+
+Types: `ReactiveUI.Binding.ReactiveSchedulerExtensions`, `ReactiveUI.Binding.ReactiveUIBindingExtensions`.
+
+#### `ReactiveSchedulerExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BindOneWayUnsafe<TSource, TTarget, TProperty>(TSource source, TTarget target, Expression<Func<TSource, TProperty>> sourceProperty, Expression<Func<TTarget, TProperty>> targetProperty, ISequencer? scheduler)` | Creates a one-way binding from a source property to a target property with a specified scheduler, resolving the property chains by reflection. | `TSource : class`: The type of the source; `TTarget : class`: The type of the target object; `TProperty`: The type of the property being bound; `TSource` `source`: The source the binding is rooted on; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; `ISequencer?` `scheduler`: The scheduler the write to the target is delivered on, or null for its owning thread; an immediate scheduler writes inline | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindOneWayUnsafe<TSource, TSourceProp, TTarget, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, Func<TSourceProp, TTargetProp> conversionFunc, ISequencer? scheduler)` | Creates a one-way binding from a source property to a target property with a conversion function and a specified scheduler, resolving the property chains by reflection. | `TSource : class`: The type of the source; `TSourceProp`: The type of the source property; `TTarget : class`: The type of the target object; `TTargetProp`: The type of the target property; `TSource` `source`: The source the binding is rooted on; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`Func<TSourceProp, TTargetProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `conversionFunc`: A function that converts the source property value to the target property type; `ISequencer?` `scheduler`: The scheduler the write to the target is delivered on, or null for its owning thread; an immediate scheduler writes inline | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindOneWayUnsafe<TSource, TSourceProp, TTarget, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, IBindingTypeConverter converter, ISequencer? scheduler, object? conversionHint)` | Creates a one-way binding from a source property to a target property using an explicit [`IBindingTypeConverter`](converters.md), resolving the property chains by reflection. | `TSource : class`: The type of the source; `TSourceProp`: The type of the source property; `TTarget : class`: The type of the target object; `TTargetProp`: The type of the target property; `TSource` `source`: The source the binding is rooted on; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`IBindingTypeConverter`](converters.md) `converter`: The binding type converter to use for converting between source and target types; `ISequencer?` `scheduler`: The scheduler the write to the target is delivered on, or null for its owning thread; an immediate scheduler writes inline; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An optional hint passed to the converter (e.g., format string) | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindTwoWayUnsafe<TSource, TTarget, TProperty>(TSource source, TTarget target, Expression<Func<TSource, TProperty>> sourceProperty, Expression<Func<TTarget, TProperty>> targetProperty, ISequencer? scheduler)` | Creates a two-way binding between a source property and a target property with a specified scheduler, resolving the property chains by reflection. | `TSource : class`: The type of the source; `TTarget : class`: The type of the target object; `TProperty`: The type of the property being bound; `TSource` `source`: The source the binding is rooted on; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; `ISequencer?` `scheduler`: The scheduler the write to the target is delivered on, or null for its owning thread; an immediate scheduler writes inline. Writes back are not scheduled | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindTwoWayUnsafe<TSource, TSourceProp, TTarget, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, Func<TSourceProp, TTargetProp> sourceToTargetConv, Func<TTargetProp, TSourceProp> targetToSourceConv, ISequencer? scheduler)` | Creates a two-way binding between a source property and a target property with conversion functions and a specified scheduler, resolving the property chains by reflection. | `TSource : class`: The type of the source; `TSourceProp`: The type of the source property; `TTarget : class`: The type of the target object; `TTargetProp`: The type of the target property; `TSource` `source`: The source the binding is rooted on; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`Func<TSourceProp, TTargetProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `sourceToTargetConv`: A function that converts the source property value to the target property type; [`Func<TTargetProp, TSourceProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `targetToSourceConv`: A function that converts the target property value back to the source property type; `ISequencer?` `scheduler`: The scheduler the write to the target is delivered on, or null for its owning thread; an immediate scheduler writes inline. Writes back are not scheduled | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindTwoWayUnsafe<TSource, TSourceProp, TTarget, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, IBindingTypeConverter sourceToTargetConverter, IBindingTypeConverter targetToSourceConverter, ISequencer? scheduler, object? conversionHint)` | Creates a two-way binding between a source property and a target property using explicit [`IBindingTypeConverter`](converters.md) instances, resolving the property chains by reflection. | `TSource : class`: The type of the source; `TSourceProp`: The type of the source property; `TTarget : class`: The type of the target object; `TTargetProp`: The type of the target property; `TSource` `source`: The source the binding is rooted on; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`IBindingTypeConverter`](converters.md) `sourceToTargetConverter`: The converter for source-to-target conversion; [`IBindingTypeConverter`](converters.md) `targetToSourceConverter`: The converter for target-to-source conversion; `ISequencer?` `scheduler`: The scheduler the write to the target is delivered on, or null for its owning thread; an immediate scheduler writes inline. Writes back are not scheduled; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An optional hint passed to the converters (e.g., format string) | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindUnsafe<TView, TViewModel, TVMProp, TVProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, Func<TVMProp, TVProp> viewModelToViewConverter, Func<TVProp, TVMProp> viewToViewModelConverter, ISequencer? scheduler)` | Creates a two-way binding between a view model property and a view property with conversion functions and a specified scheduler, resolving the property chains by reflection. | `TView : class, IViewFor`: The type of the view; `TViewModel : class`: The type of the view model; `TVMProp`: The type of the view model property; `TVProp`: The type of the view property; `TView` `view`: The view the binding is rooted on; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`Func<TVMProp, TVProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `viewModelToViewConverter`: A function that converts the view model property value to the view property type; [`Func<TVProp, TVMProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `viewToViewModelConverter`: A function that converts the view property value back to the view model property type; `ISequencer?` `scheduler`: The scheduler the write to the view is delivered on, or null for its owning thread; an immediate scheduler writes inline. Writes back are not scheduled | [`IReactiveBinding<TView, BindingChange>`](bindings.md): A reactive binding that can be disposed to disconnect the binding. |
+| `BindUnsafe<TView, TViewModel, TVMProp, TVProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, IBindingTypeConverter viewModelToViewConverter, IBindingTypeConverter viewToViewModelConverter, ISequencer? scheduler, object? conversionHint)` | Creates a two-way binding between a view model property and a view property using explicit [`IBindingTypeConverter`](converters.md) instances, resolving the property chains by reflection. | `TView : class, IViewFor`: The type of the view; `TViewModel : class`: The type of the view model; `TVMProp`: The type of the view model property; `TVProp`: The type of the view property; `TView` `view`: The view the binding is rooted on; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`IBindingTypeConverter`](converters.md) `viewModelToViewConverter`: The converter for view model-to-view conversion; [`IBindingTypeConverter`](converters.md) `viewToViewModelConverter`: The converter for view-to-view model conversion; `ISequencer?` `scheduler`: The scheduler the write to the view is delivered on, or null for its owning thread; an immediate scheduler writes inline. Writes back are not scheduled; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An optional hint passed to the converters (e.g., format string) | [`IReactiveBinding<TView, BindingChange>`](bindings.md): A reactive binding that can be disposed to disconnect the binding. |
+| `OneWayBindUnsafe<TView, TViewModel, TProp, TOut>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TProp>> viewModelProperty, Expression<Func<TView, TOut>> viewProperty, Func<TProp, TOut> selector, ISequencer? scheduler)` | Creates a one-way binding from a view model property to a view property with a specified selector and scheduler, resolving the property chains by reflection. | `TView : class, IViewFor`: The type of the view; `TViewModel : class`: The type of the view model; `TProp`: The type of the view model property; `TOut`: The type of the view property; `TView` `view`: The view the binding is rooted on; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TOut>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`Func<TProp, TOut>`](https://learn.microsoft.com/dotnet/api/system.func-2) `selector`: A function that converts the view model property value to the view property type; `ISequencer?` `scheduler`: The scheduler the write to the view is delivered on, or null for its owning thread; an immediate scheduler writes inline | [`IReactiveBinding<TView, TOut>`](bindings.md): A reactive binding that can be disposed to disconnect the binding. |
+| `OneWayBindUnsafe<TView, TViewModel, TVMProp, TVProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, IBindingTypeConverter converter, ISequencer? scheduler, object? conversionHint)` | Creates a one-way binding from a view model property to a view property using an explicit [`IBindingTypeConverter`](converters.md), resolving the property chains by reflection. | `TView : class, IViewFor`: The type of the view; `TViewModel : class`: The type of the view model; `TVMProp`: The type of the view model property; `TVProp`: The type of the view property; `TView` `view`: The view the binding is rooted on; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`IBindingTypeConverter`](converters.md) `converter`: The binding type converter to use for converting between source and target types; `ISequencer?` `scheduler`: The scheduler the write to the view is delivered on, or null for its owning thread; an immediate scheduler writes inline; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An optional hint passed to the converter (e.g., format string) | [`IReactiveBinding<TView, TVProp>`](bindings.md): A reactive binding that can be disposed to disconnect the binding. |
+
+#### `ReactiveUIBindingExtensions`
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BindCommandUnsafe<TView, TViewModel, TProp, TControl>(TView view, TViewModel? viewModel, Expression<Func<TViewModel, TProp?>> propertyName, Expression<Func<TView, TControl>> controlName, string? toEvent)` | Binds the command a view model property holds to the control a view property holds, rebinding when either changes. | `TView : class, IViewFor`: The type of the view; `TViewModel : class`: The type of the view model; `TProp : ICommand`: The type of the command property; `TControl : class`: The type of the control; `TView` `view`: The view to bind to; `TViewModel?` `viewModel`: The view model containing the command; null binds nothing; [`Expression<Func<TViewModel, TProp?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `propertyName`: An expression that selects the command property on the view model; [`Expression<Func<TView, TControl>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `controlName`: An expression that selects the control on the view; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `toEvent`: The event name to bind to. If null, a default event is selected | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindCommandUnsafe<TView, TViewModel, TProp, TControl, TParam>(TView view, TViewModel? viewModel, Expression<Func<TViewModel, TProp?>> propertyName, Expression<Func<TView, TControl>> controlName, IObservable<TParam?> withParameter, string? toEvent)` | Binds the command a view model property holds to the control a view property holds, using an observable as the source of the command parameter. | `TView : class, IViewFor`: The type of the view; `TViewModel : class`: The type of the view model; `TProp : ICommand`: The type of the command property; `TControl : class`: The type of the control; `TParam`: The type of the command parameter; `TView` `view`: The view to bind to; `TViewModel?` `viewModel`: The view model containing the command; null binds nothing; [`Expression<Func<TViewModel, TProp?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `propertyName`: An expression that selects the command property on the view model; [`Expression<Func<TView, TControl>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `controlName`: An expression that selects the control on the view; [`IObservable<TParam?>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `withParameter`: An observable that provides the command parameter; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `toEvent`: The event name to bind to. If null, a default event is selected | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindCommandUnsafe<TView, TViewModel, TProp, TControl, TParam>(TView view, TViewModel? viewModel, Expression<Func<TViewModel, TProp?>> propertyName, Expression<Func<TView, TControl>> controlName, Expression<Func<TViewModel, TParam?>> withParameter, string? toEvent)` | Binds the command a view model property holds to the control a view property holds, using a view model property as the command parameter. | `TView : class, IViewFor`: The type of the view; `TViewModel : class`: The type of the view model; `TProp : ICommand`: The type of the command property; `TControl : class`: The type of the control; `TParam`: The type of the command parameter; `TView` `view`: The view to bind to; `TViewModel?` `viewModel`: The view model containing the command; null binds nothing; [`Expression<Func<TViewModel, TProp?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `propertyName`: An expression that selects the command property on the view model; [`Expression<Func<TView, TControl>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `controlName`: An expression that selects the control on the view; [`Expression<Func<TViewModel, TParam?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `withParameter`: An expression that selects the command parameter property on the view model; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `toEvent`: The event name to bind to. If null, a default event is selected | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindInteractionUnsafe<TViewModel, TView, TInput, TOutput>(TView view, TViewModel? viewModel, Expression<Func<TViewModel, IInteraction<TInput, TOutput>>> propertyName, Func<IInteractionContext<TInput, TOutput>, Task> handler)` | Registers a task-based handler on the interaction a view model property holds, moving it to the new interaction when the property changes. | `TViewModel : class`: The type of the view model; `TView : class, IViewFor`: The type of the view; `TInput`: The type of the interaction's input; `TOutput`: The type of the interaction's output; `TView` `view`: The view that provides the handler; `TViewModel?` `viewModel`: The view model that exposes the interaction; null registers nothing; [`Expression<Func<TViewModel, IInteraction<TInput, TOutput>>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `propertyName`: An expression that selects the interaction property on the view model; [`Func<IInteractionContext<TInput, TOutput>, Task>`](https://learn.microsoft.com/dotnet/api/system.func-2) `handler`: A task-based handler for the interaction | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, unregisters the handler and stops observing the property. |
+| `BindInteractionUnsafe<TViewModel, TView, TInput, TOutput, TDontCare>(TView view, TViewModel? viewModel, Expression<Func<TViewModel, IInteraction<TInput, TOutput>>> propertyName, Func<IInteractionContext<TInput, TOutput>, IObservable<TDontCare>> handler)` | Registers an observable-based handler on the interaction a view model property holds, moving it to the new interaction when the property changes. | `TViewModel : class`: The type of the view model; `TView : class, IViewFor`: The type of the view; `TInput`: The type of the interaction's input; `TOutput`: The type of the interaction's output; `TDontCare`: The signal type of the observable handler; `TView` `view`: The view that provides the handler; `TViewModel?` `viewModel`: The view model that exposes the interaction; null registers nothing; [`Expression<Func<TViewModel, IInteraction<TInput, TOutput>>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `propertyName`: An expression that selects the interaction property on the view model; [`Func<IInteractionContext<TInput, TOutput>, IObservable<TDontCare>>`](https://learn.microsoft.com/dotnet/api/system.func-2) `handler`: An observable-based handler for the interaction | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, unregisters the handler and stops observing the property. |
+| `BindOneWayUnsafe<TSource, TTarget, TProperty>(TSource source, TTarget target, Expression<Func<TSource, TProperty>> sourceProperty, Expression<Func<TTarget, TProperty>> targetProperty)` | Binds a source property to a target property one way, writing the current value and each later change on the target's owning thread. | `TSource : class`: The type of the source object; `TTarget : class`: The type of the target object; `TProperty`: The type of the property being bound; `TSource` `source`: The source object to observe for property changes; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindOneWayUnsafe<TSource, TSourceProp, TTarget, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, Func<TSourceProp, TTargetProp> conversionFunc)` | Binds a source property to a target property one way through a conversion function, writing on the target's owning thread. | `TSource : class`: The type of the source object; `TSourceProp`: The type of the source property; `TTarget : class`: The type of the target object; `TTargetProp`: The type of the target property; `TSource` `source`: The source object to observe for property changes; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`Func<TSourceProp, TTargetProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `conversionFunc`: A function that converts the source property value to the target property type | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `IObservable<TValue>.BindToUnsafe<TValue, TTarget, TTargetValue>(TTarget? target, Expression<Func<TTarget, TTargetValue?>> property)` | Writes each value the source produces to a target property, resolving the property chain by reflection. | `TValue`: The type of the value produced by the source observable; `TTarget : class`: The type of the target object; `TTargetValue`: The type of the property on the target object; [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source` (receiver): The observable stream to bind to a target property; `TTarget?` `target`: The target object whose property will be set; [`Expression<Func<TTarget, TTargetValue?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: An expression that selects the target property to set | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `IObservable<TValue>.BindToUnsafe<TValue, TTarget, TTargetValue>(TTarget? target, Expression<Func<TTarget, TTargetValue?>> property, IBindingTypeConverter? converterOverride)` | Writes each value the source produces to a target property, converting it with the supplied converter and resolving the property chain by reflection. | `TValue`: The type of the value produced by the source observable; `TTarget : class`: The type of the target object; `TTargetValue`: The type of the property on the target object; [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source` (receiver): The observable stream to bind to a target property; `TTarget?` `target`: The target object whose property will be set; [`Expression<Func<TTarget, TTargetValue?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: An expression that selects the target property to set; [`IBindingTypeConverter?`](converters.md) `converterOverride`: An explicit converter to use when converting the source value to the target property type | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `IObservable<TValue>.BindToUnsafe<TValue, TTarget, TTargetValue>(TTarget? target, Expression<Func<TTarget, TTargetValue?>> property, object? conversionHint)` | Writes each value the source produces to a target property, passing the conversion hint to the converter and resolving the property chain by reflection. | `TValue`: The type of the value produced by the source observable; `TTarget : class`: The type of the target object; `TTargetValue`: The type of the property on the target object; [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source` (receiver): The observable stream to bind to a target property; `TTarget?` `target`: The target object whose property will be set; [`Expression<Func<TTarget, TTargetValue?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: An expression that selects the target property to set; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An object that provides a hint to the converter. The semantics are defined by the converter | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `IObservable<TValue>.BindToUnsafe<TValue, TTarget, TTargetValue>(TTarget? target, Expression<Func<TTarget, TTargetValue?>> property, object? conversionHint, IBindingTypeConverter? converterOverride)` | Writes each value the source produces to a target property, converting it with the supplied converter and conversion hint and resolving the property chain by reflection. | `TValue`: The type of the value produced by the source observable; `TTarget : class`: The type of the target object; `TTargetValue`: The type of the property on the target object; [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source` (receiver): The observable stream to bind to a target property; `TTarget?` `target`: The target object whose property will be set; [`Expression<Func<TTarget, TTargetValue?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: An expression that selects the target property to set; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An object that provides a hint to the converter. The semantics are defined by the converter; [`IBindingTypeConverter?`](converters.md) `converterOverride`: An explicit converter to use when converting the source value to the target property type | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindTwoWayUnsafe<TSource, TTarget, TProperty>(TSource source, TTarget target, Expression<Func<TSource, TProperty>> sourceProperty, Expression<Func<TTarget, TProperty>> targetProperty)` | Binds a source and a target property to each other, seeding the target from the source and mirroring each change on the other side's owning thread. | `TSource : class`: The type of the source object; `TTarget : class`: The type of the target object; `TProperty`: The type of the property being bound; `TSource` `source`: The source object to observe for property changes; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TProperty>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindTwoWayUnsafe<TSource, TSourceProp, TTarget, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, Func<TSourceProp, TTargetProp> sourceToTargetConv, Func<TTargetProp, TSourceProp> targetToSourceConv)` | Binds a source and a target property to each other through conversion functions, seeding the target and mirroring each change on the other side's owning thread. | `TSource : class`: The type of the source object; `TSourceProp`: The type of the source property; `TTarget : class`: The type of the target object; `TTargetProp`: The type of the target property; `TSource` `source`: The source object to observe for property changes; `TTarget` `target`: The target object whose property will be updated; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: An expression that selects the source property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: An expression that selects the target property to update; [`Func<TSourceProp, TTargetProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `sourceToTargetConv`: A function that converts the source property value to the target property type; [`Func<TTargetProp, TSourceProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `targetToSourceConv`: A function that converts the target property value back to the source property type | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, disconnects the binding. |
+| `BindUnsafe<TViewModel, TView, TVMProp, TVProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty)` | Creates a two-way binding between a view model property and a view property, resolving the property chains by reflection. | `TViewModel : class`: The type of the view model; `TView : class, IViewFor`: The type of the view; `TVMProp`: The type of the view model property; `TVProp`: The type of the view property; `TView` `view`: The view to bind to; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update | [`IReactiveBinding<TView, BindingChange>`](bindings.md): The binding; its change stream reports each value with the side it came from, and disposing it disconnects both directions. |
+| `BindUnsafe<TViewModel, TView, TVMProp, TVProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, Func<TVMProp, TVProp> viewModelToViewConverter, Func<TVProp, TVMProp> viewToViewModelConverter)` | Creates a two-way binding between a view model property and a view property with conversion functions, resolving the property chains by reflection. | `TViewModel : class`: The type of the view model; `TView : class, IViewFor`: The type of the view; `TVMProp`: The type of the view model property; `TVProp`: The type of the view property; `TView` `view`: The view to bind to; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`Func<TVMProp, TVProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `viewModelToViewConverter`: A function that converts the view model property value to the view property type; [`Func<TVProp, TVMProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `viewToViewModelConverter`: A function that converts the view property value back to the view model property type | [`IReactiveBinding<TView, BindingChange>`](bindings.md): The binding; its change stream reports each value with the side it came from, and disposing it disconnects both directions. |
+| `BindUnsafe<TViewModel, TView, TVMProp, TVProp, TDontCare>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, IObservable<TDontCare>? signalViewUpdate, TriggerUpdate triggerUpdate = ViewToViewModel)` | Binds a view model property and a view property in both directions, with an update stream driving one direction. | `TViewModel : class`: The view model type; `TView : class, IViewFor`: The view type; `TVMProp`: The view model property type; `TVProp`: The view property type; `TDontCare`: The ignored signal payload; `TView` `view`: The view to bind; `TViewModel` `viewModel`: The view model to bind; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: The view model property path; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: The view property path; [`IObservable<TDontCare>?`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `signalViewUpdate`: The update stream, or null to observe both properties' own notifications; [`TriggerUpdate`](unsafe.md) `triggerUpdate`: The direction the update stream drives; see [`TriggerUpdate`](unsafe.md) | [`IReactiveBinding<TView, BindingChange>`](bindings.md): The binding; its change stream reports each write with the side it came from, and disposing it disconnects both directions. |
+| `BindUnsafe<TViewModel, TView, TVMProp, TVProp, TDontCare>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, Func<TVMProp, TVProp> viewModelToViewConverter, Func<TVProp, TVMProp> viewToViewModelConverter, IObservable<TDontCare>? signalViewUpdate, TriggerUpdate triggerUpdate = ViewToViewModel)` | Binds a view model property and a view property in both directions with explicit conversions, with an update stream driving one direction. | `TViewModel : class`: The view model type; `TView : class, IViewFor`: The view type; `TVMProp`: The view model property type; `TVProp`: The view property type; `TDontCare`: The ignored signal payload; `TView` `view`: The view to bind; `TViewModel` `viewModel`: The view model to bind; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: The view model property path; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: The view property path; [`Func<TVMProp, TVProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `viewModelToViewConverter`: Converts a value written to the view; [`Func<TVProp, TVMProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `viewToViewModelConverter`: Converts a value written to the view model; [`IObservable<TDontCare>?`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `signalViewUpdate`: The update stream, or null to observe both properties' own notifications; [`TriggerUpdate`](unsafe.md) `triggerUpdate`: The direction the update stream drives; see [`TriggerUpdate`](unsafe.md) | [`IReactiveBinding<TView, BindingChange>`](bindings.md): The binding; its change stream reports each write with the side it came from, and disposing it disconnects both directions. |
+| `IObservable<T>.InvokeCommandUnsafe<T, TTarget>(TTarget? target, Expression<Func<TTarget, ICommand?>> commandProperty)` | Executes the command a property holds with each value as its parameter, skipping a value while there is no command or the command cannot execute it. | `T`: The type of the value offered as the command parameter; `TTarget : class`: The type declaring the command property; [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source` (receiver): The sequence driving the executions; `TTarget?` `target`: The object declaring the command property; null executes nothing; [`Expression<Func<TTarget, ICommand?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `commandProperty`: An expression that selects the command property to execute | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, stops executing the command and stops observing the property. |
+| `OneWayBindUnsafe<TViewModel, TView, TVMProp, TVProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty)` | Binds a view model property to a view property one way, writing the current value and each later change on the view's owning thread. | `TViewModel : class`: The type of the view model; `TView : class, IViewFor`: The type of the view; `TVMProp`: The type of the view model property; `TVProp`: The type of the view property; `TView` `view`: The view to bind to; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update | [`IReactiveBinding<TView, TVProp>`](bindings.md): A reactive binding that can be disposed to disconnect the binding. |
+| `OneWayBindUnsafe<TViewModel, TView, TProp, TOut>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TProp>> viewModelProperty, Expression<Func<TView, TOut>> viewProperty, Func<TProp, TOut> selector)` | Binds a view model property to a view property one way through a selector, writing on the view's owning thread. | `TViewModel : class`: The type of the view model; `TView : class, IViewFor`: The type of the view; `TProp`: The type of the view model property; `TOut`: The type of the view property; `TView` `view`: The view to bind to; `TViewModel` `viewModel`: The view model to observe; [`Expression<Func<TViewModel, TProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: An expression that selects the view model property to observe; [`Expression<Func<TView, TOut>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: An expression that selects the view property to update; [`Func<TProp, TOut>`](https://learn.microsoft.com/dotnet/api/system.func-2) `selector`: A function that converts the view model property value to the view property type | [`IReactiveBinding<TView, TOut>`](bindings.md): A reactive binding that can be disposed to disconnect the binding. |
+| `WhenAnyObservableUnsafe<TSender, TRet>(TSender sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7, Expression<Func<TSender, IObservable<TRet>?>> obs8, Expression<Func<TSender, IObservable<TRet>?>> obs9, Expression<Func<TSender, IObservable<TRet>?>> obs10, Expression<Func<TSender, IObservable<TRet>?>> obs11, Expression<Func<TSender, IObservable<TRet>?>> obs12)` | Observes 12 observable-valued properties by reflection and merges the values of their current observables, each switching when its property changes. Available for 1 to 12 repeated arguments; the largest form is listed. | `TSender : class`: The type of the sender to monitor for property changes; `TRet`: The element type of the observed observables; `TSender` `sender`: The sender instance to observe for property changes; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs1`: An expression that selects observable property 1 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs2`: An expression that selects observable property 2 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs3`: An expression that selects observable property 3 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs4`: An expression that selects observable property 4 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs5`: An expression that selects observable property 5 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs6`: An expression that selects observable property 6 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs7`: An expression that selects observable property 7 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs8`: An expression that selects observable property 8 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs9`: An expression that selects observable property 9 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs10`: An expression that selects observable property 10 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs11`: An expression that selects observable property 11 to observe; [`Expression<Func<TSender, IObservable<TRet>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs12`: An expression that selects observable property 12 to observe | [`IObservable<TRet>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable sequence that emits values from the merged observed observables. |
+| `WhenAnyObservableUnsafe<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(TSender sender, Expression<Func<TSender, IObservable<T1>?>> obs1, Expression<Func<TSender, IObservable<T2>?>> obs2, Expression<Func<TSender, IObservable<T3>?>> obs3, Expression<Func<TSender, IObservable<T4>?>> obs4, Expression<Func<TSender, IObservable<T5>?>> obs5, Expression<Func<TSender, IObservable<T6>?>> obs6, Expression<Func<TSender, IObservable<T7>?>> obs7, Expression<Func<TSender, IObservable<T8>?>> obs8, Expression<Func<TSender, IObservable<T9>?>> obs9, Expression<Func<TSender, IObservable<T10>?>> obs10, Expression<Func<TSender, IObservable<T11>?>> obs11, Expression<Func<TSender, IObservable<T12>?>> obs12, Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet> selector)` | Observes 12 observable-valued properties of different element types by reflection and applies a selector to their latest values once every observable has produced one. Available for 2 to 12 repeated arguments; the largest form is listed. | `TSender : class`: The type of the sender to monitor for property changes; `TRet`: The return type of the selector; `T1`: The element type of observable property 1; `T2`: The element type of observable property 2; `T3`: The element type of observable property 3; `T4`: The element type of observable property 4; `T5`: The element type of observable property 5; `T6`: The element type of observable property 6; `T7`: The element type of observable property 7; `T8`: The element type of observable property 8; `T9`: The element type of observable property 9; `T10`: The element type of observable property 10; `T11`: The element type of observable property 11; `T12`: The element type of observable property 12; `TSender` `sender`: The sender instance to observe for property changes; [`Expression<Func<TSender, IObservable<T1>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs1`: An expression that selects observable property 1 to observe; [`Expression<Func<TSender, IObservable<T2>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs2`: An expression that selects observable property 2 to observe; [`Expression<Func<TSender, IObservable<T3>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs3`: An expression that selects observable property 3 to observe; [`Expression<Func<TSender, IObservable<T4>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs4`: An expression that selects observable property 4 to observe; [`Expression<Func<TSender, IObservable<T5>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs5`: An expression that selects observable property 5 to observe; [`Expression<Func<TSender, IObservable<T6>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs6`: An expression that selects observable property 6 to observe; [`Expression<Func<TSender, IObservable<T7>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs7`: An expression that selects observable property 7 to observe; [`Expression<Func<TSender, IObservable<T8>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs8`: An expression that selects observable property 8 to observe; [`Expression<Func<TSender, IObservable<T9>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs9`: An expression that selects observable property 9 to observe; [`Expression<Func<TSender, IObservable<T10>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs10`: An expression that selects observable property 10 to observe; [`Expression<Func<TSender, IObservable<T11>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs11`: An expression that selects observable property 11 to observe; [`Expression<Func<TSender, IObservable<T12>?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `obs12`: An expression that selects observable property 12 to observe; [`Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet>`](https://learn.microsoft.com/dotnet/api/system.func-13) `selector`: A function that combines the latest values from all observables | [`IObservable<TRet>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable sequence of selector results. |
+| `WhenAnyUnsafe<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(TSender sender, Expression<Func<TSender, T1>> property1, Expression<Func<TSender, T2>> property2, Expression<Func<TSender, T3>> property3, Expression<Func<TSender, T4>> property4, Expression<Func<TSender, T5>> property5, Expression<Func<TSender, T6>> property6, Expression<Func<TSender, T7>> property7, Expression<Func<TSender, T8>> property8, Expression<Func<TSender, T9>> property9, Expression<Func<TSender, T10>> property10, Expression<Func<TSender, T11>> property11, Expression<Func<TSender, T12>> property12, Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, IObservedChange<TSender, T7>, IObservedChange<TSender, T8>, IObservedChange<TSender, T9>, IObservedChange<TSender, T10>, IObservedChange<TSender, T11>, IObservedChange<TSender, T12>, TRet> selector)` | Observes 12 properties by reflection and applies a selector to their observed changes, first on subscription and again after any of them changes. Available for 1 to 12 repeated arguments; the largest form is listed. | `TSender : class`: The type of the sender to monitor for property changes; `TRet`: The return type of the selector; `T1`: The type of property 1 value; `T2`: The type of property 2 value; `T3`: The type of property 3 value; `T4`: The type of property 4 value; `T5`: The type of property 5 value; `T6`: The type of property 6 value; `T7`: The type of property 7 value; `T8`: The type of property 8 value; `T9`: The type of property 9 value; `T10`: The type of property 10 value; `T11`: The type of property 11 value; `T12`: The type of property 12 value; `TSender` `sender`: The sender instance to observe for property changes; [`Expression<Func<TSender, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects property 1 to observe; [`Expression<Func<TSender, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects property 2 to observe; [`Expression<Func<TSender, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects property 3 to observe; [`Expression<Func<TSender, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects property 4 to observe; [`Expression<Func<TSender, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects property 5 to observe; [`Expression<Func<TSender, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects property 6 to observe; [`Expression<Func<TSender, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects property 7 to observe; [`Expression<Func<TSender, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects property 8 to observe; [`Expression<Func<TSender, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects property 9 to observe; [`Expression<Func<TSender, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects property 10 to observe; [`Expression<Func<TSender, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects property 11 to observe; [`Expression<Func<TSender, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects property 12 to observe; [`Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, IObservedChange<TSender, T7>, IObservedChange<TSender, T8>, IObservedChange<TSender, T9>, IObservedChange<TSender, T10>, IObservedChange<TSender, T11>, IObservedChange<TSender, T12>, TRet>`](https://learn.microsoft.com/dotnet/api/system.func-13) `selector`: A function that combines the observed changes into a result | [`IObservable<TRet>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable sequence of selector results. |
+| `WhenAnyValueUnsafe<TSender, T1>(TSender sender, Expression<Func<TSender, T1>> property1)` | Observes a property by reflection, emitting its current value on subscription and its new value after each change. This is a ReactiveUI compatibility shim. | `TSender : class`: The type of the sender to monitor for property changes; `T1`: The type of the first observed property value; `TSender` `sender`: The sender instance to observe for property changes; [`Expression<Func<TSender, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe | [`IObservable<T1>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable sequence that emits the property value when it changes. |
+| `WhenAnyValueUnsafe<TSender, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>(TSender sender, Expression<Func<TSender, T1>> property1, Expression<Func<TSender, T2>> property2, Expression<Func<TSender, T3>> property3, Expression<Func<TSender, T4>> property4, Expression<Func<TSender, T5>> property5, Expression<Func<TSender, T6>> property6, Expression<Func<TSender, T7>> property7, Expression<Func<TSender, T8>> property8, Expression<Func<TSender, T9>> property9, Expression<Func<TSender, T10>> property10, Expression<Func<TSender, T11>> property11, Expression<Func<TSender, T12>> property12, Expression<Func<TSender, T13>> property13, Expression<Func<TSender, T14>> property14, Expression<Func<TSender, T15>> property15, Expression<Func<TSender, T16>> property16)` | Observes 16 properties by reflection and emits their values as a tuple, first on subscription and again after any of them changes. This is a ReactiveUI compatibility shim. Available for 2 to 16 repeated arguments; the largest form is listed. | `TSender : class`: The type of the sender to monitor for property changes; `T1`: The type of the first observed property value; `T2`: The type of the second observed property value; `T3`: The type of the third observed property value; `T4`: The type of the fourth observed property value; `T5`: The type of the fifth observed property value; `T6`: The type of the sixth observed property value; `T7`: The type of the seventh observed property value; `T8`: The type of the eighth observed property value; `T9`: The type of the ninth observed property value; `T10`: The type of the tenth observed property value; `T11`: The type of the eleventh observed property value; `T12`: The type of the twelfth observed property value; `T13`: The type of the thirteenth observed property value; `T14`: The type of the fourteenth observed property value; `T15`: The type of the fifteenth observed property value; `T16`: The type of the sixteenth observed property value; `TSender` `sender`: The sender instance to observe for property changes; [`Expression<Func<TSender, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`Expression<Func<TSender, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects the second property to observe; [`Expression<Func<TSender, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects the third property to observe; [`Expression<Func<TSender, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects the fourth property to observe; [`Expression<Func<TSender, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects the fifth property to observe; [`Expression<Func<TSender, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects the sixth property to observe; [`Expression<Func<TSender, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects the seventh property to observe; [`Expression<Func<TSender, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects the eighth property to observe; [`Expression<Func<TSender, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects the ninth property to observe; [`Expression<Func<TSender, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects the tenth property to observe; [`Expression<Func<TSender, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects the eleventh property to observe; [`Expression<Func<TSender, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects the twelfth property to observe; [`Expression<Func<TSender, T13>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property13`: An expression that selects the thirteenth property to observe; [`Expression<Func<TSender, T14>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property14`: An expression that selects the fourteenth property to observe; [`Expression<Func<TSender, T15>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property15`: An expression that selects the fifteenth property to observe; [`Expression<Func<TSender, T16>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property16`: An expression that selects the sixteenth property to observe | [`IObservable<PropertyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable sequence that emits a tuple of all observed property values when any of them changes. |
+| `WhenAnyValueUnsafe<TSender, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TRet>(TSender sender, Expression<Func<TSender, T1>> property1, Expression<Func<TSender, T2>> property2, Expression<Func<TSender, T3>> property3, Expression<Func<TSender, T4>> property4, Expression<Func<TSender, T5>> property5, Expression<Func<TSender, T6>> property6, Expression<Func<TSender, T7>> property7, Expression<Func<TSender, T8>> property8, Expression<Func<TSender, T9>> property9, Expression<Func<TSender, T10>> property10, Expression<Func<TSender, T11>> property11, Expression<Func<TSender, T12>> property12, Expression<Func<TSender, T13>> property13, Expression<Func<TSender, T14>> property14, Expression<Func<TSender, T15>> property15, Expression<Func<TSender, T16>> property16, Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TRet> selector)` | Observes 16 properties by reflection and emits the selector's result for their values, first on subscription and again after any of them changes. This is a ReactiveUI compatibility shim. Available for 1 to 16 repeated arguments; the largest form is listed. | `TSender : class`: The type of the sender to monitor for property changes; `T1`: The type of the first observed property value; `T2`: The type of the second observed property value; `T3`: The type of the third observed property value; `T4`: The type of the fourth observed property value; `T5`: The type of the fifth observed property value; `T6`: The type of the sixth observed property value; `T7`: The type of the seventh observed property value; `T8`: The type of the eighth observed property value; `T9`: The type of the ninth observed property value; `T10`: The type of the tenth observed property value; `T11`: The type of the eleventh observed property value; `T12`: The type of the twelfth observed property value; `T13`: The type of the thirteenth observed property value; `T14`: The type of the fourteenth observed property value; `T15`: The type of the fifteenth observed property value; `T16`: The type of the sixteenth observed property value; `TRet`: The return type of the selector function; `TSender` `sender`: The sender instance to observe for property changes; [`Expression<Func<TSender, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`Expression<Func<TSender, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects the second property to observe; [`Expression<Func<TSender, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects the third property to observe; [`Expression<Func<TSender, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects the fourth property to observe; [`Expression<Func<TSender, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects the fifth property to observe; [`Expression<Func<TSender, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects the sixth property to observe; [`Expression<Func<TSender, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects the seventh property to observe; [`Expression<Func<TSender, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects the eighth property to observe; [`Expression<Func<TSender, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects the ninth property to observe; [`Expression<Func<TSender, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects the tenth property to observe; [`Expression<Func<TSender, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects the eleventh property to observe; [`Expression<Func<TSender, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects the twelfth property to observe; [`Expression<Func<TSender, T13>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property13`: An expression that selects the thirteenth property to observe; [`Expression<Func<TSender, T14>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property14`: An expression that selects the fourteenth property to observe; [`Expression<Func<TSender, T15>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property15`: An expression that selects the fifteenth property to observe; [`Expression<Func<TSender, T16>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property16`: An expression that selects the sixteenth property to observe; [`Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TRet>`](https://learn.microsoft.com/dotnet/api/system.func-17) `selector`: A function that converts the observed property values to the return type | [`IObservable<TRet>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable sequence that emits the selector result when any of the observed properties changes. |
+| `WhenChangedUnsafe<TObj, T1>(TObj objectToMonitor, Expression<Func<TObj, T1>> property1)` | Observes a property by reflection, emitting its current value on subscription and its new value after each change. | `TObj : class`: The type of the object to monitor for property changes; `T1`: The type of the first observed property value; `TObj` `objectToMonitor`: The object instance to observe for property changes; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe | [`IObservable<T1>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable sequence that emits the property value when it changes. |
+| `WhenChangedUnsafe<TObj, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>(TObj objectToMonitor, Expression<Func<TObj, T1>> property1, Expression<Func<TObj, T2>> property2, Expression<Func<TObj, T3>> property3, Expression<Func<TObj, T4>> property4, Expression<Func<TObj, T5>> property5, Expression<Func<TObj, T6>> property6, Expression<Func<TObj, T7>> property7, Expression<Func<TObj, T8>> property8, Expression<Func<TObj, T9>> property9, Expression<Func<TObj, T10>> property10, Expression<Func<TObj, T11>> property11, Expression<Func<TObj, T12>> property12, Expression<Func<TObj, T13>> property13, Expression<Func<TObj, T14>> property14, Expression<Func<TObj, T15>> property15, Expression<Func<TObj, T16>> property16)` | Observes 16 properties by reflection and emits their values as a tuple, first on subscription and again after any of them changes. Available for 2 to 16 repeated arguments; the largest form is listed. | `TObj : class`: The type of the object to monitor for property changes; `T1`: The type of the first observed property value; `T2`: The type of the second observed property value; `T3`: The type of the third observed property value; `T4`: The type of the fourth observed property value; `T5`: The type of the fifth observed property value; `T6`: The type of the sixth observed property value; `T7`: The type of the seventh observed property value; `T8`: The type of the eighth observed property value; `T9`: The type of the ninth observed property value; `T10`: The type of the tenth observed property value; `T11`: The type of the eleventh observed property value; `T12`: The type of the twelfth observed property value; `T13`: The type of the thirteenth observed property value; `T14`: The type of the fourteenth observed property value; `T15`: The type of the fifteenth observed property value; `T16`: The type of the sixteenth observed property value; `TObj` `objectToMonitor`: The object instance to observe for property changes; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`Expression<Func<TObj, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects the second property to observe; [`Expression<Func<TObj, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects the third property to observe; [`Expression<Func<TObj, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects the fourth property to observe; [`Expression<Func<TObj, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects the fifth property to observe; [`Expression<Func<TObj, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects the sixth property to observe; [`Expression<Func<TObj, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects the seventh property to observe; [`Expression<Func<TObj, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects the eighth property to observe; [`Expression<Func<TObj, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects the ninth property to observe; [`Expression<Func<TObj, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects the tenth property to observe; [`Expression<Func<TObj, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects the eleventh property to observe; [`Expression<Func<TObj, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects the twelfth property to observe; [`Expression<Func<TObj, T13>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property13`: An expression that selects the thirteenth property to observe; [`Expression<Func<TObj, T14>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property14`: An expression that selects the fourteenth property to observe; [`Expression<Func<TObj, T15>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property15`: An expression that selects the fifteenth property to observe; [`Expression<Func<TObj, T16>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property16`: An expression that selects the sixteenth property to observe | [`IObservable<PropertyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable sequence that emits a tuple of all observed property values when any of them changes. |
+| `WhenChangedUnsafe<TObj, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TReturn>(TObj objectToMonitor, Expression<Func<TObj, T1>> property1, Expression<Func<TObj, T2>> property2, Expression<Func<TObj, T3>> property3, Expression<Func<TObj, T4>> property4, Expression<Func<TObj, T5>> property5, Expression<Func<TObj, T6>> property6, Expression<Func<TObj, T7>> property7, Expression<Func<TObj, T8>> property8, Expression<Func<TObj, T9>> property9, Expression<Func<TObj, T10>> property10, Expression<Func<TObj, T11>> property11, Expression<Func<TObj, T12>> property12, Expression<Func<TObj, T13>> property13, Expression<Func<TObj, T14>> property14, Expression<Func<TObj, T15>> property15, Expression<Func<TObj, T16>> property16, Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TReturn> conversionFunc)` | Observes 16 properties by reflection and emits the conversion function's result for their values, first on subscription and again after any of them changes. Available for 2 to 16 repeated arguments; the largest form is listed. | `TObj : class`: The type of the object to monitor for property changes; `T1`: The type of the first observed property value; `T2`: The type of the second observed property value; `T3`: The type of the third observed property value; `T4`: The type of the fourth observed property value; `T5`: The type of the fifth observed property value; `T6`: The type of the sixth observed property value; `T7`: The type of the seventh observed property value; `T8`: The type of the eighth observed property value; `T9`: The type of the ninth observed property value; `T10`: The type of the tenth observed property value; `T11`: The type of the eleventh observed property value; `T12`: The type of the twelfth observed property value; `T13`: The type of the thirteenth observed property value; `T14`: The type of the fourteenth observed property value; `T15`: The type of the fifteenth observed property value; `T16`: The type of the sixteenth observed property value; `TReturn`: The return type of the conversion function; `TObj` `objectToMonitor`: The object instance to observe for property changes; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`Expression<Func<TObj, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects the second property to observe; [`Expression<Func<TObj, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects the third property to observe; [`Expression<Func<TObj, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects the fourth property to observe; [`Expression<Func<TObj, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects the fifth property to observe; [`Expression<Func<TObj, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects the sixth property to observe; [`Expression<Func<TObj, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects the seventh property to observe; [`Expression<Func<TObj, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects the eighth property to observe; [`Expression<Func<TObj, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects the ninth property to observe; [`Expression<Func<TObj, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects the tenth property to observe; [`Expression<Func<TObj, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects the eleventh property to observe; [`Expression<Func<TObj, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects the twelfth property to observe; [`Expression<Func<TObj, T13>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property13`: An expression that selects the thirteenth property to observe; [`Expression<Func<TObj, T14>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property14`: An expression that selects the fourteenth property to observe; [`Expression<Func<TObj, T15>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property15`: An expression that selects the fifteenth property to observe; [`Expression<Func<TObj, T16>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property16`: An expression that selects the sixteenth property to observe; [`Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TReturn>`](https://learn.microsoft.com/dotnet/api/system.func-17) `conversionFunc`: A function that converts the observed property values to the return type | [`IObservable<TReturn>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable sequence that emits the converted result when any of the observed properties changes. |
+| `WhenChangingUnsafe<TObj, T1>(TObj objectToMonitor, Expression<Func<TObj, T1>> property1)` | Observes a property by reflection, emitting its current value on subscription and its value before each change. | `TObj : class`: The type of the object to monitor for property changes; `T1`: The type of the first observed property value; `TObj` `objectToMonitor`: The object instance to observe for property changes; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe | [`IObservable<T1>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable sequence that emits the property value before it changes. |
+| `WhenChangingUnsafe<TObj, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>(TObj objectToMonitor, Expression<Func<TObj, T1>> property1, Expression<Func<TObj, T2>> property2, Expression<Func<TObj, T3>> property3, Expression<Func<TObj, T4>> property4, Expression<Func<TObj, T5>> property5, Expression<Func<TObj, T6>> property6, Expression<Func<TObj, T7>> property7, Expression<Func<TObj, T8>> property8, Expression<Func<TObj, T9>> property9, Expression<Func<TObj, T10>> property10, Expression<Func<TObj, T11>> property11, Expression<Func<TObj, T12>> property12, Expression<Func<TObj, T13>> property13, Expression<Func<TObj, T14>> property14, Expression<Func<TObj, T15>> property15, Expression<Func<TObj, T16>> property16)` | Observes 16 properties by reflection and emits their values as a tuple, first on subscription and again before any of them changes. Available for 2 to 16 repeated arguments; the largest form is listed. | `TObj : class`: The type of the object to monitor for property changes; `T1`: The type of the first observed property value; `T2`: The type of the second observed property value; `T3`: The type of the third observed property value; `T4`: The type of the fourth observed property value; `T5`: The type of the fifth observed property value; `T6`: The type of the sixth observed property value; `T7`: The type of the seventh observed property value; `T8`: The type of the eighth observed property value; `T9`: The type of the ninth observed property value; `T10`: The type of the tenth observed property value; `T11`: The type of the eleventh observed property value; `T12`: The type of the twelfth observed property value; `T13`: The type of the thirteenth observed property value; `T14`: The type of the fourteenth observed property value; `T15`: The type of the fifteenth observed property value; `T16`: The type of the sixteenth observed property value; `TObj` `objectToMonitor`: The object instance to observe for property changes; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`Expression<Func<TObj, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects the second property to observe; [`Expression<Func<TObj, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects the third property to observe; [`Expression<Func<TObj, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects the fourth property to observe; [`Expression<Func<TObj, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects the fifth property to observe; [`Expression<Func<TObj, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects the sixth property to observe; [`Expression<Func<TObj, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects the seventh property to observe; [`Expression<Func<TObj, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects the eighth property to observe; [`Expression<Func<TObj, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects the ninth property to observe; [`Expression<Func<TObj, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects the tenth property to observe; [`Expression<Func<TObj, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects the eleventh property to observe; [`Expression<Func<TObj, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects the twelfth property to observe; [`Expression<Func<TObj, T13>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property13`: An expression that selects the thirteenth property to observe; [`Expression<Func<TObj, T14>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property14`: An expression that selects the fourteenth property to observe; [`Expression<Func<TObj, T15>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property15`: An expression that selects the fifteenth property to observe; [`Expression<Func<TObj, T16>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property16`: An expression that selects the sixteenth property to observe | [`IObservable<PropertyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable sequence that emits a tuple of all observed property values before any of them changes. |
+| `WhenChangingUnsafe<TObj, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TReturn>(TObj objectToMonitor, Expression<Func<TObj, T1>> property1, Expression<Func<TObj, T2>> property2, Expression<Func<TObj, T3>> property3, Expression<Func<TObj, T4>> property4, Expression<Func<TObj, T5>> property5, Expression<Func<TObj, T6>> property6, Expression<Func<TObj, T7>> property7, Expression<Func<TObj, T8>> property8, Expression<Func<TObj, T9>> property9, Expression<Func<TObj, T10>> property10, Expression<Func<TObj, T11>> property11, Expression<Func<TObj, T12>> property12, Expression<Func<TObj, T13>> property13, Expression<Func<TObj, T14>> property14, Expression<Func<TObj, T15>> property15, Expression<Func<TObj, T16>> property16, Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TReturn> conversionFunc)` | Observes 16 properties by reflection and emits the conversion function's result for their values, first on subscription and again before any of them changes. Available for 2 to 16 repeated arguments; the largest form is listed. | `TObj : class`: The type of the object to monitor for property changes; `T1`: The type of the first observed property value; `T2`: The type of the second observed property value; `T3`: The type of the third observed property value; `T4`: The type of the fourth observed property value; `T5`: The type of the fifth observed property value; `T6`: The type of the sixth observed property value; `T7`: The type of the seventh observed property value; `T8`: The type of the eighth observed property value; `T9`: The type of the ninth observed property value; `T10`: The type of the tenth observed property value; `T11`: The type of the eleventh observed property value; `T12`: The type of the twelfth observed property value; `T13`: The type of the thirteenth observed property value; `T14`: The type of the fourteenth observed property value; `T15`: The type of the fifteenth observed property value; `T16`: The type of the sixteenth observed property value; `TReturn`: The return type of the conversion function; `TObj` `objectToMonitor`: The object instance to observe for property changes; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: An expression that selects the first property to observe; [`Expression<Func<TObj, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: An expression that selects the second property to observe; [`Expression<Func<TObj, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: An expression that selects the third property to observe; [`Expression<Func<TObj, T4>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property4`: An expression that selects the fourth property to observe; [`Expression<Func<TObj, T5>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property5`: An expression that selects the fifth property to observe; [`Expression<Func<TObj, T6>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property6`: An expression that selects the sixth property to observe; [`Expression<Func<TObj, T7>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property7`: An expression that selects the seventh property to observe; [`Expression<Func<TObj, T8>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property8`: An expression that selects the eighth property to observe; [`Expression<Func<TObj, T9>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property9`: An expression that selects the ninth property to observe; [`Expression<Func<TObj, T10>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property10`: An expression that selects the tenth property to observe; [`Expression<Func<TObj, T11>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property11`: An expression that selects the eleventh property to observe; [`Expression<Func<TObj, T12>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property12`: An expression that selects the twelfth property to observe; [`Expression<Func<TObj, T13>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property13`: An expression that selects the thirteenth property to observe; [`Expression<Func<TObj, T14>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property14`: An expression that selects the fourteenth property to observe; [`Expression<Func<TObj, T15>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property15`: An expression that selects the fifteenth property to observe; [`Expression<Func<TObj, T16>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property16`: An expression that selects the sixteenth property to observe; [`Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, TReturn>`](https://learn.microsoft.com/dotnet/api/system.func-17) `conversionFunc`: A function that converts the observed property values to the return type | [`IObservable<TReturn>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable sequence that emits the converted result before any of the observed properties changes. |
+
+### Trigger updates
+
+[Full description and examples](unsafe.md).
+
+Types: `ReactiveUI.Binding.TriggerUpdate`.
+
+#### `TriggerUpdate`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `enum TriggerUpdate` | Selects the direction driven by a binding's supplied update stream. | None. | — |
+
+**Enum values**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ViewToViewModel = 0` | The stream replaces view notifications and requests writes to the view model. | None. | — |
+| `ViewModelToView = 1` | The stream requests writes to the view in place of view model notifications after the first; view notifications are still observed. | None. | — |
+
+### Runtime fallback
+
+[Full description and examples](unsafe.md).
+
+Types: `ReactiveUI.Binding.Fallback.RuntimeBindingConverter`, `ReactiveUI.Binding.Fallback.RuntimeBindingFallback`, `ReactiveUI.Binding.Fallback.RuntimeCommandBindingFallback`, `ReactiveUI.Binding.Fallback.RuntimeCommandFallback`, `ReactiveUI.Binding.Fallback.RuntimeInteractionFallback`, `ReactiveUI.Binding.Fallback.RuntimeObservationFallback`.
+
+#### `RuntimeBindingConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class RuntimeBindingConverter` | Runtime conversion entry point used by generated `BindTo` bindings to coerce a source value to the target property type when the two differ, or when an explicit converter or conversion hint is supplied. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `TryConvert<TFrom, TTo>(TFrom value, object? conversionHint, IBindingTypeConverter? converterOverride, out TTo result)` | Attempts to convert `value` from `TFrom` to `TTo` for a generated `BindTo` assignment. | `TFrom`: The declared source value type; `TTo`: The target property type; `TFrom` `value`: The value produced by the source observable; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An optional conversion hint forwarded to the converter; [`IBindingTypeConverter?`](converters.md) `converterOverride`: An optional explicit converter that takes precedence over the registry; out `TTo` `result`: The converted value when conversion succeeds | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise `false`. |
+
+#### `RuntimeBindingFallback`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class RuntimeBindingFallback` | Drives a binding through the runtime observation engine instead of the generated one. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Bind<TViewModel, TView, TProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TProp>> viewModelProperty, Expression<Func<TView, TProp>> viewProperty, ISequencer? scheduler, string bindingExpression)` | Binds a view-model property and a view property of the same type to each other. | `TViewModel : class`: The type declaring the view-model property; `TView : class, IViewFor`: The type declaring the view property; `TProp`: The type of the value carried across the binding; `TView` `view`: The view side of the binding; `TViewModel` `viewModel`: The view-model side of the binding; [`Expression<Func<TViewModel, TProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: The property on `viewModel`; [`Expression<Func<TView, TProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: The property on `view`; `ISequencer?` `scheduler`: The sequencer the view write is delivered on, or null to write on the thread that owns it; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `bindingExpression`: The bound expression, named when a write faults | [`IReactiveBinding<TView, BindingChange>`](bindings.md): The binding, which disconnects both directions when disposed. |
+| `Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, IObservable<TDontCare>? signalViewUpdate, TriggerUpdate triggerUpdate)` | Binds properties using converter registration and direction signals. | `TViewModel : class`: The view model type; `TView : class, IViewFor`: The view type; `TVMProp`: The view model property type; `TVProp`: The view property type; `TDontCare`: The ignored signal payload; `TView` `view`: The view to bind; `TViewModel` `viewModel`: The view model to bind; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: The view model property path; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: The view property path; [`IObservable<TDontCare>?`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `signalViewUpdate`: The update stream, or null to observe both properties; [`TriggerUpdate`](unsafe.md) `triggerUpdate`: The direction driven by the stream | [`IReactiveBinding<TView, BindingChange>`](bindings.md): The connected two-way binding. |
+| `Bind<TViewModel, TView, TViewModelProp, TViewProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TViewModelProp>> viewModelProperty, Expression<Func<TView, TViewProp>> viewProperty, TwoWayConverterPair<TViewModelProp, TViewProp> converters, ISequencer? scheduler, string bindingExpression)` | Binds a view-model property and a view property of differing types, converting in both directions. | `TViewModel : class`: The type declaring the view-model property; `TView : class, IViewFor`: The type declaring the view property; `TViewModelProp`: The type of the view-model property; `TViewProp`: The type of the view property; `TView` `view`: The view side of the binding; `TViewModel` `viewModel`: The view-model side of the binding; [`Expression<Func<TViewModel, TViewModelProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: The property on `viewModel`; [`Expression<Func<TView, TViewProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: The property on `view`; [`TwoWayConverterPair<TViewModelProp, TViewProp>`](converters.md) `converters`: Converts view model to view, and view back to view model; `ISequencer?` `scheduler`: The sequencer the view write is delivered on, or null to write on the thread that owns it; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `bindingExpression`: The bound expression, named when a write faults | [`IReactiveBinding<TView, BindingChange>`](bindings.md): The binding, which disconnects both directions when disposed. |
+| `Bind<TViewModel, TView, TVMProp, TVProp, TDontCare>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TVMProp>> viewModelProperty, Expression<Func<TView, TVProp>> viewProperty, TwoWayConverterPair<TVMProp, TVProp> conversions, IObservable<TDontCare>? signalViewUpdate, TriggerUpdate triggerUpdate)` | Binds properties using explicit conversions and direction signals. | `TViewModel : class`: The view model type; `TView : class, IViewFor`: The view type; `TVMProp`: The view model property type; `TVProp`: The view property type; `TDontCare`: The ignored signal payload; `TView` `view`: The view to bind; `TViewModel` `viewModel`: The view model to bind; [`Expression<Func<TViewModel, TVMProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: The view model property path; [`Expression<Func<TView, TVProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: The view property path; [`TwoWayConverterPair<TVMProp, TVProp>`](converters.md) `conversions`: The conversions applied before comparison and writing; [`IObservable<TDontCare>?`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `signalViewUpdate`: The update stream, or null to observe both properties; [`TriggerUpdate`](unsafe.md) `triggerUpdate`: The direction driven by the stream | [`IReactiveBinding<TView, BindingChange>`](bindings.md): The connected two-way binding. |
+| `BindOneWay<TSource, TTarget, TProp>(TSource source, TTarget target, Expression<Func<TSource, TProp>> sourceProperty, Expression<Func<TTarget, TProp>> targetProperty, ISequencer? scheduler, string bindingExpression)` | Binds a source property one way onto a target property of the same type. | `TSource : class`: The type declaring the observed property; `TTarget`: The type declaring the written property; `TProp`: The type of the value carried across the binding; `TSource` `source`: The object to observe; `TTarget` `target`: The object to write to; [`Expression<Func<TSource, TProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: The property to observe; [`Expression<Func<TTarget, TProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: The property to write; `ISequencer?` `scheduler`: The sequencer the write is delivered on, or null to write on the thread that owns it; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `bindingExpression`: The bound expression, named when a write faults | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that disconnects the binding. |
+| `BindOneWay<TSource, TTarget, TSourceProp, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, Func<TSourceProp, TTargetProp> conversion, ISequencer? scheduler, string bindingExpression)` | Binds a source property one way onto a target property of another type, applying a conversion. | `TSource : class`: The type declaring the observed property; `TTarget`: The type declaring the written property; `TSourceProp`: The type of the observed property; `TTargetProp`: The type of the written property; `TSource` `source`: The object to observe; `TTarget` `target`: The object to write to; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: The property to observe; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: The property to write; [`Func<TSourceProp, TTargetProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `conversion`: Converts the observed value to the written one; `ISequencer?` `scheduler`: The sequencer the write is delivered on, or null to write on the thread that owns it; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `bindingExpression`: The bound expression, named when a write faults | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that disconnects the binding. |
+| `BindTo<TValue, TTarget, TTargetValue>(IObservable<TValue> source, TTarget? target, Expression<Func<TTarget, TTargetValue>> targetProperty, object? conversionHint, IBindingTypeConverter? converterOverride, ISequencer? scheduler, string bindingExpression)` | Writes every value a sequence produces into a property, converting it on the way. | `TValue`: The type the sequence produces; `TTarget : class`: The type declaring the written property; `TTargetValue`: The type of the written property; [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source`: The sequence driving the writes; `TTarget?` `target`: The object declaring the written property; [`Expression<Func<TTarget, TTargetValue>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: The property to write; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: An optional hint handed to the converter; [`IBindingTypeConverter?`](converters.md) `converterOverride`: A converter that takes precedence over the registered ones; `ISequencer?` `scheduler`: The scheduler the writes are delivered on, or null to write on the thread that owns it; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `bindingExpression`: The bound expression, named when a write faults | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, stops writing. |
+| `BindTwoWay<TSource, TTarget, TProp>(TSource source, TTarget target, Expression<Func<TSource, TProp>> sourceProperty, Expression<Func<TTarget, TProp>> targetProperty, ISequencer? scheduler, string bindingExpression)` | Binds a source and a target property of the same type to each other. | `TSource : class`: The type declaring the source property; `TTarget : class`: The type declaring the target property; `TProp`: The type of the value carried across the binding; `TSource` `source`: The first object of the binding; `TTarget` `target`: The second object of the binding; [`Expression<Func<TSource, TProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: The property on `source`; [`Expression<Func<TTarget, TProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: The property on `target`; `ISequencer?` `scheduler`: The sequencer the target write is delivered on, or null to write on the thread that owns it; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `bindingExpression`: The bound expression, named when a write faults | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that disconnects both directions. |
+| `BindTwoWay<TSource, TTarget, TSourceProp, TTargetProp>(TSource source, TTarget target, Expression<Func<TSource, TSourceProp>> sourceProperty, Expression<Func<TTarget, TTargetProp>> targetProperty, TwoWayConverterPair<TSourceProp, TTargetProp> converters, ISequencer? scheduler, string bindingExpression)` | Binds a source and a target property of differing types to each other, converting in both directions. | `TSource : class`: The type declaring the source property; `TTarget : class`: The type declaring the target property; `TSourceProp`: The type of the source property; `TTargetProp`: The type of the target property; `TSource` `source`: The first object of the binding; `TTarget` `target`: The second object of the binding; [`Expression<Func<TSource, TSourceProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `sourceProperty`: The property on `source`; [`Expression<Func<TTarget, TTargetProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `targetProperty`: The property on `target`; [`TwoWayConverterPair<TSourceProp, TTargetProp>`](converters.md) `converters`: Converts source to target, and target back to source; `ISequencer?` `scheduler`: The sequencer the target write is delivered on, or null to write on the thread that owns it; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `bindingExpression`: The bound expression, named when a write faults | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that disconnects both directions. |
+| `OneWayBind<TViewModel, TView, TProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TProp>> viewModelProperty, Expression<Func<TView, TProp>> viewProperty, ISequencer? scheduler, string bindingExpression)` | Binds a view-model property one way onto a view property of the same type. | `TViewModel : class`: The type declaring the view-model property; `TView : IViewFor`: The type declaring the view property; `TProp`: The type of the value carried across the binding; `TView` `view`: The view being written to; `TViewModel` `viewModel`: The view model being observed; [`Expression<Func<TViewModel, TProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: The property to observe; [`Expression<Func<TView, TProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: The property to write; `ISequencer?` `scheduler`: The sequencer the write is delivered on, or null to write on the thread that owns it; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `bindingExpression`: The bound expression, named when a write faults | [`IReactiveBinding<TView, TProp>`](bindings.md): The binding, which disconnects when disposed. |
+| `OneWayBind<TViewModel, TView, TViewModelProp, TViewProp>(TView view, TViewModel viewModel, Expression<Func<TViewModel, TViewModelProp>> viewModelProperty, Expression<Func<TView, TViewProp>> viewProperty, Func<TViewModelProp, TViewProp> conversion, ISequencer? scheduler, string bindingExpression)` | Binds a view-model property one way onto a view property of another type, applying a conversion. | `TViewModel : class`: The type declaring the view-model property; `TView : IViewFor`: The type declaring the view property; `TViewModelProp`: The type of the view-model property; `TViewProp`: The type of the view property; `TView` `view`: The view being written to; `TViewModel` `viewModel`: The view model being observed; [`Expression<Func<TViewModel, TViewModelProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewModelProperty`: The property to observe; [`Expression<Func<TView, TViewProp>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `viewProperty`: The property to write; [`Func<TViewModelProp, TViewProp>`](https://learn.microsoft.com/dotnet/api/system.func-2) `conversion`: Converts the observed value to the view's type; `ISequencer?` `scheduler`: The sequencer the write is delivered on, or null to write on the thread that owns it; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `bindingExpression`: The bound expression, named when a write faults | [`IReactiveBinding<TView, TViewProp>`](bindings.md): The binding, which disconnects when disposed. |
+
+#### `RuntimeCommandBindingFallback`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class RuntimeCommandBindingFallback` | Binds a command to a control, resolving the command and control properties at runtime. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BindCommand<TView, TViewModel, TProp, TControl>(TView view, TViewModel? viewModel, Expression<Func<TViewModel, TProp?>> commandProperty, Expression<Func<TView, TControl>> controlProperty, IObservable<object?> commandParameter, string? toEvent, string bindingExpression)` | Keeps the command an observed property holds bound to the control another one holds. | `TView : class`: The type declaring the control property; `TViewModel : class`: The type declaring the command property; `TProp : ICommand`: The type of the command property; `TControl : class`: The type of the control the command is bound to; `TView` `view`: The object declaring the control property; `TViewModel?` `viewModel`: The object declaring the command property; [`Expression<Func<TViewModel, TProp?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `commandProperty`: The property holding the command to bind; [`Expression<Func<TView, TControl>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `controlProperty`: The property holding the control to bind it to; [`IObservable<object?>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `commandParameter`: The values offered as the command parameter; [`string?`](https://learn.microsoft.com/dotnet/api/system.string) `toEvent`: The control event that executes the command, or null for the control's default; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `bindingExpression`: The bound expression, named when the observation faults | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, unbinds the command and stops observing. |
+
+#### `RuntimeCommandFallback`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class RuntimeCommandFallback` | Resolves the command an `InvokeCommand` executes through the runtime expression engine. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `InvokeCommand<T, TTarget>(IObservable<T> source, TTarget? target, Expression<Func<TTarget, ICommand?>> commandProperty)` | Executes the command an observed property holds with each value the sequence produces. | `T`: The type of the value offered as the command parameter; `TTarget : class`: The type declaring the observed command property; [`IObservable<T>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1) `source`: The sequence driving the executions; `TTarget?` `target`: The object declaring the command property; [`Expression<Func<TTarget, ICommand?>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `commandProperty`: The property holding the command to execute | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, stops executing the command. |
+
+#### `RuntimeInteractionFallback`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class RuntimeInteractionFallback` | Registers an interaction handler against a property the runtime expression engine resolves. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BindInteraction<TViewModel, TInput, TOutput>(TViewModel? viewModel, Expression<Func<TViewModel, IInteraction<TInput, TOutput>>> interactionProperty, Func<IInteraction<TInput, TOutput>, IDisposable> register, string bindingExpression)` | Keeps a handler registered against whichever interaction the observed property holds. | `TViewModel : class`: The type declaring the interaction property; `TInput`: The type the interaction takes; `TOutput`: The type the interaction produces; `TViewModel?` `viewModel`: The object declaring the interaction property; [`Expression<Func<TViewModel, IInteraction<TInput, TOutput>>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `interactionProperty`: The property holding the interaction to handle; [`Func<IInteraction<TInput, TOutput>, IDisposable>`](https://learn.microsoft.com/dotnet/api/system.func-2) `register`: Registers the caller's handler against one interaction; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `bindingExpression`: The bound expression, named when the observation faults | [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable): A disposable that, when disposed, unregisters the handler and stops observing. |
+
+#### `RuntimeObservationFallback`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class RuntimeObservationFallback` | Observes properties of WhenChanged, WhenChanging and WhenAnyValue calls the source generator did not handle, by walking the property expression at runtime and resolving each link through the registered [`ICreatesObservableForProperty`](mechanisms.md) implementations. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `WhenAnyValue<TSender, TValue>(TSender sender, Expression<Func<TSender, TValue>> property)` | Observes a property, emitting its value after each change. | `TSender : class`: The type of object being observed; `TValue`: The type of the property value; `TSender` `sender`: The object to observe; [`Expression<Func<TSender, TValue>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: The property expression | [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits property values after they change. |
+| `WhenAnyValue<TSender, T1, T2>(TSender sender, Expression<Func<TSender, T1>> property1, Expression<Func<TSender, T2>> property2)` | Observes two properties, emitting both values whenever either changes. | `TSender : class`: The type of object being observed; `T1`: The type of the first property value; `T2`: The type of the second property value; `TSender` `sender`: The object to observe; [`Expression<Func<TSender, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: The first property expression; [`Expression<Func<TSender, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: The second property expression | [`IObservable<PropertyValues<T1, T2>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits a tuple of property values when any changes. |
+| `WhenAnyValue<TSender, T1, T2, T3>(TSender sender, Expression<Func<TSender, T1>> property1, Expression<Func<TSender, T2>> property2, Expression<Func<TSender, T3>> property3)` | Observes three properties, emitting all their values whenever any changes. | `TSender : class`: The type of object being observed; `T1`: The type of the first property value; `T2`: The type of the second property value; `T3`: The type of the third property value; `TSender` `sender`: The object to observe; [`Expression<Func<TSender, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: The first property expression; [`Expression<Func<TSender, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: The second property expression; [`Expression<Func<TSender, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: The third property expression | [`IObservable<PropertyValues<T1, T2, T3>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits a tuple of property values when any changes. |
+| `WhenChanged<TObj, TValue>(TObj obj, Expression<Func<TObj, TValue>> property)` | Observes a property, emitting its value after each change. | `TObj : class`: The type of object being observed; `TValue`: The type of the property value; `TObj` `obj`: The object to observe; [`Expression<Func<TObj, TValue>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: The property expression | [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits property values after they change. |
+| `WhenChanged<TObj, T1, T2>(TObj obj, Expression<Func<TObj, T1>> property1, Expression<Func<TObj, T2>> property2)` | Observes two properties, emitting both values whenever either changes. | `TObj : class`: The type of object being observed; `T1`: The type of the first property value; `T2`: The type of the second property value; `TObj` `obj`: The object to observe; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: The first property expression; [`Expression<Func<TObj, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: The second property expression | [`IObservable<PropertyValues<T1, T2>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits a tuple of property values when any changes. |
+| `WhenChanged<TObj, T1, T2, T3>(TObj obj, Expression<Func<TObj, T1>> property1, Expression<Func<TObj, T2>> property2, Expression<Func<TObj, T3>> property3)` | Observes three properties, emitting all their values whenever any changes. | `TObj : class`: The type of object being observed; `T1`: The type of the first property value; `T2`: The type of the second property value; `T3`: The type of the third property value; `TObj` `obj`: The object to observe; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: The first property expression; [`Expression<Func<TObj, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: The second property expression; [`Expression<Func<TObj, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: The third property expression | [`IObservable<PropertyValues<T1, T2, T3>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits a tuple of property values when any changes. |
+| `WhenChanging<TObj, TValue>(TObj obj, Expression<Func<TObj, TValue>> property)` | Observes a property, emitting its value just before each change. | `TObj : class`: The type of object being observed; `TValue`: The type of the property value; `TObj` `obj`: The object to observe; [`Expression<Func<TObj, TValue>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property`: The property expression | [`IObservable<TValue>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits property values before they change. |
+| `WhenChanging<TObj, T1, T2>(TObj obj, Expression<Func<TObj, T1>> property1, Expression<Func<TObj, T2>> property2)` | Observes two properties, emitting both values whenever either is about to change. | `TObj : class`: The type of object being observed; `T1`: The type of the first property value; `T2`: The type of the second property value; `TObj` `obj`: The object to observe; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: The first property expression; [`Expression<Func<TObj, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: The second property expression | [`IObservable<PropertyValues<T1, T2>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits a tuple of property values before any changes. |
+| `WhenChanging<TObj, T1, T2, T3>(TObj obj, Expression<Func<TObj, T1>> property1, Expression<Func<TObj, T2>> property2, Expression<Func<TObj, T3>> property3)` | Observes three properties, emitting all their values whenever any is about to change. | `TObj : class`: The type of object being observed; `T1`: The type of the first property value; `T2`: The type of the second property value; `T3`: The type of the third property value; `TObj` `obj`: The object to observe; [`Expression<Func<TObj, T1>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property1`: The first property expression; [`Expression<Func<TObj, T2>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property2`: The second property expression; [`Expression<Func<TObj, T3>>`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression-1) `property3`: The third property expression | [`IObservable<PropertyValues<T1, T2, T3>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that emits a tuple of property values before any changes. |
+
+## Platforms
+
+### WPF
+
+[Full description and examples](threading.md).
+
+Types: `ReactiveUI.Binding.Wpf.BooleanToVisibilityHints`, `ReactiveUI.Binding.Wpf.BooleanToVisibilityTypeConverter`, `ReactiveUI.Binding.Wpf.Builder.WpfBindingBuilderExtensions`, `ReactiveUI.Binding.Wpf.DependencyObjectObservableForProperty`, `ReactiveUI.Binding.Wpf.DispatcherViewThreadInvoker`, `ReactiveUI.Binding.Wpf.VisibilityToBooleanTypeConverter`, `ReactiveUI.Binding.Wpf.WpfBindingModule`.
+
+#### `BooleanToVisibilityHints`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `enum BooleanToVisibilityHints` | Conversion hints, passed as the conversion hint, that change how a boolean maps to a `Visibility`. | None. | — |
+
+**Enum values**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `None = 0` | True is Visible and false is Collapsed. | None. | — |
+| `Inverse = 2` | Swaps the mapping, so true is not visible and false is Visible. | None. | — |
+| `UseHidden = 4` | Uses Hidden rather than Collapsed as the value that is not visible. | None. | — |
+
+#### `BooleanToVisibilityTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class BooleanToVisibilityTypeConverter : BindingTypeConverter<bool, Visibility>` | Converts a [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) to `Visible` or `Collapsed`; the conversion always succeeds. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BooleanToVisibilityTypeConverter()` | Initializes a new instance of the BooleanToVisibilityTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(bool from, object? conversionHint, out Visibility result)` | Converts a value to the target type without boxing. | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`Visibility`](https://learn.microsoft.com/dotnet/api/system.windows.visibility) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `WpfBindingBuilderExtensions`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class WpfBindingBuilderExtensions` | WPF-specific extensions for the ReactiveUI.Binding builder. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `IReactiveUIBindingBuilder.WithWpf()` | Registers the WPF module, which adds dependency-property observation and the dispatcher view thread invoker. | [`IReactiveUIBindingBuilder`](setup.md) `builder` (receiver) | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `IAppBuilder.WithWpf()` | Registers the WPF module, which adds dependency-property observation and the dispatcher view thread invoker. | `IAppBuilder` `builder` (receiver) | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+
+#### `DependencyObjectObservableForProperty`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `class DependencyObjectObservableForProperty` | Observes a WPF `DependencyObject` property through its `{PropertyName}Property` dependency property. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `DependencyObjectObservableForProperty()` | Initializes a new instance of the DependencyObjectObservableForProperty class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObject(Type type, string propertyName, bool beforeChanged)` | Returns the WPF dependency-object affinity when the type declares a public static `{propertyName}Property` field. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `type`: The type that owns the property; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name, without the `Property` suffix; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Ignored | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): `WpfDependencyObject` for a `DependencyObject` type with such a field; otherwise zero. |
+| `GetNotificationForProperty(object sender, Expression expression, string propertyName, bool beforeChanged, bool suppressWarnings)` | Returns an observable that raises whenever the dependency property changes on `sender`. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `sender`: The `DependencyObject` to observe; [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The expression carried on each notification; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name, without the `Property` suffix; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Ignored; notifications are always after the change; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `suppressWarnings`: `true` to skip the debug message written when no descriptor is found | [`IObservable<IObservedChange<object, object?>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that subscribes to the descriptor's value-changed event and unsubscribes on disposal. |
+
+#### `DispatcherViewThreadInvoker`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class DispatcherViewThreadInvoker` | Routes writes to a WPF `DispatcherObject` onto the thread its dispatcher owns. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `DispatcherViewThreadInvoker()` | Initializes a new instance of the DispatcherViewThreadInvoker class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `CheckAccess(object target)` | Returns whether the calling thread owns the target's dispatcher. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: A `DispatcherObject`; any other type throws [`InvalidCastException`](https://learn.microsoft.com/dotnet/api/system.invalidcastexception) | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` when the calling thread may touch the target. |
+| `Claims(object target)` | Determines whether this invoker handles `target`. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: The object a binding writes to | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` when the object belongs to this invoker's platform; otherwise `false`. |
+| `Post(object target, Action<object?> callback, object? state)` | Queues `callback` on the target's dispatcher at normal priority, or runs it inline when the target has no dispatcher. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: A `DispatcherObject`; any other type throws [`InvalidCastException`](https://learn.microsoft.com/dotnet/api/system.invalidcastexception); [`Action<object?>`](https://learn.microsoft.com/dotnet/api/system.action-1) `callback`: The callback to run; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `state`: The value passed to `callback` | — |
+
+#### `VisibilityToBooleanTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class VisibilityToBooleanTypeConverter : BindingTypeConverter<Visibility, bool>` | Converts a [`Visibility`](https://learn.microsoft.com/dotnet/api/system.windows.visibility) to a [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean), true for Visible and false for Hidden or Collapsed; the conversion always succeeds. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `VisibilityToBooleanTypeConverter()` | Initializes a new instance of the VisibilityToBooleanTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(Visibility from, object? conversionHint, out bool result)` | Converts a value to the target type without boxing. | [`Visibility`](https://learn.microsoft.com/dotnet/api/system.windows.visibility) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `WpfBindingModule`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class WpfBindingModule` | Registers the WPF dependency-property observer and view thread invoker with the dependency resolver. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `WpfBindingModule()` | Initializes a new instance of the WpfBindingModule class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Configure(IMutableDependencyResolver resolver)` | Configures the specified dependency resolver with required services and components. | `IMutableDependencyResolver` `resolver`: The dependency resolver to configure. Cannot be null | — |
+
+### WinForms
+
+[Full description and examples](threading.md).
+
+Types: `ReactiveUI.Binding.WinForms.Builder.WinFormsBindingBuilderExtensions`, `ReactiveUI.Binding.WinForms.ControlViewThreadInvoker`, `ReactiveUI.Binding.WinForms.WinFormsBindingModule`, `ReactiveUI.Binding.WinForms.WinFormsCreatesObservableForProperty`.
+
+#### `WinFormsBindingBuilderExtensions`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class WinFormsBindingBuilderExtensions` | WinForms-specific extensions for the ReactiveUI.Binding builder. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `IReactiveUIBindingBuilder.WithWinForms()` | Registers the WinForms module, which adds event-based property observation and the control view thread invoker. | [`IReactiveUIBindingBuilder`](setup.md) `builder` (receiver) | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `IAppBuilder.WithWinForms()` | Registers the WinForms module, which adds event-based property observation and the control view thread invoker. | `IAppBuilder` `builder` (receiver) | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+
+#### `ControlViewThreadInvoker`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class ControlViewThreadInvoker` | Routes writes to a WinForms `Control` onto the thread that created its handle. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `ControlViewThreadInvoker()` | Initializes a new instance of the ControlViewThreadInvoker class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `CheckAccess(object target)` | Returns whether the calling thread may write to the control; also true while the control has no handle. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: A `Control`; any other type throws [`InvalidCastException`](https://learn.microsoft.com/dotnet/api/system.invalidcastexception) | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` when `InvokeRequired` is false. |
+| `Claims(object target)` | Determines whether this invoker handles `target`. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: The object a binding writes to | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` when the object belongs to this invoker's platform; otherwise `false`. |
+| `Post(object target, Action<object?> callback, object? state)` | Queues `callback` with `BeginInvoke`, or runs it inline when no invoke is required. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: A `Control`; any other type throws [`InvalidCastException`](https://learn.microsoft.com/dotnet/api/system.invalidcastexception); [`Action<object?>`](https://learn.microsoft.com/dotnet/api/system.action-1) `callback`: The callback to run; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `state`: The value passed to `callback` | — |
+
+#### `WinFormsBindingModule`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class WinFormsBindingModule` | Registers the WinForms event-based property observer and view thread invoker with the dependency resolver. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `WinFormsBindingModule()` | Initializes a new instance of the WinFormsBindingModule class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Configure(IMutableDependencyResolver resolver)` | Configures the specified dependency resolver with required services and components. | `IMutableDependencyResolver` `resolver`: The dependency resolver to configure. Cannot be null | — |
+
+#### `WinFormsCreatesObservableForProperty`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `class WinFormsCreatesObservableForProperty` | Observes a WinForms `Component` property by subscribing to its public `{PropertyName}Changed` event through reflection. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `WinFormsCreatesObservableForProperty()` | Initializes a new instance of the WinFormsCreatesObservableForProperty class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `GetAffinityForObject(Type type, string propertyName, bool beforeChanged)` | Returns the WinForms event affinity when the component type has a public instance `{propertyName}Changed` event. | [`Type`](https://learn.microsoft.com/dotnet/api/system.type) `type`: The type that owns the property; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name, without the `Changed` suffix; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: `true` always yields zero, since WinForms raises no before-change event | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): `WinFormsEvent` for a `Component` type with such an event; otherwise zero. |
+| `GetNotificationForProperty(object sender, Expression expression, string propertyName, bool beforeChanged, bool suppressWarnings)` | Returns an observable that raises whenever `sender` raises its `{propertyName}Changed` event. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `sender`: The component to observe; [`Expression`](https://learn.microsoft.com/dotnet/api/system.linq.expressions.expression) `expression`: The expression carried on each notification; [`string`](https://learn.microsoft.com/dotnet/api/system.string) `propertyName`: The property name, without the `Changed` suffix; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `beforeChanged`: Ignored; notifications are always after the change; [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `suppressWarnings`: Ignored | [`IObservable<IObservedChange<object, object?>>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1): An observable that adds the event handler on subscription and removes it on disposal. |
+
+### .NET MAUI
+
+[Full description and examples](threading.md).
+
+Types: `ReactiveUI.Binding.Maui.BooleanToVisibilityHints`, `ReactiveUI.Binding.Maui.BooleanToVisibilityTypeConverter`, `ReactiveUI.Binding.Maui.Builder.MauiBindingBuilderExtensions`, `ReactiveUI.Binding.Maui.DispatcherViewThreadInvoker`, `ReactiveUI.Binding.Maui.MauiBindingModule`, `ReactiveUI.Binding.Maui.VisibilityToBooleanTypeConverter`.
+
+#### `BooleanToVisibilityHints`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `enum BooleanToVisibilityHints` | Conversion hints, passed as the conversion hint, that change how a boolean maps to a `Visibility`. | None. | — |
+
+**Enum values**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `None = 0` | True is Visible and false is Collapsed. | None. | — |
+| `Inverse = 2` | Swaps the mapping, so true is not visible and false is Visible. | None. | — |
+| `UseHidden = 4` | Uses Hidden rather than Collapsed as the value that is not visible; ignored on WinUI, which has no Hidden. | None. | — |
+
+#### `BooleanToVisibilityTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class BooleanToVisibilityTypeConverter : BindingTypeConverter<bool, Visibility>` | Converts a [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) to `Visible` or `Collapsed`; the conversion always succeeds. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `BooleanToVisibilityTypeConverter()` | Initializes a new instance of the BooleanToVisibilityTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(bool from, object? conversionHint, out Visibility result)` | Converts a value to the target type without boxing. | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`Visibility`](https://learn.microsoft.com/dotnet/api/microsoft.maui.visibility) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
+
+#### `MauiBindingBuilderExtensions`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `static class MauiBindingBuilderExtensions` | MAUI-specific extensions for the ReactiveUI.Binding builder. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `IReactiveUIBindingBuilder.WithMaui()` | Registers the MAUI module, which adds the view thread invoker, the Visibility converters and, in the WinUI build, dependency-property observation. | [`IReactiveUIBindingBuilder`](setup.md) `builder` (receiver) | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+| `IAppBuilder.WithMaui()` | Registers the MAUI module, which adds the view thread invoker, the Visibility converters and, in the WinUI build, dependency-property observation. | `IAppBuilder` `builder` (receiver) | [`IReactiveUIBindingBuilder`](setup.md): The builder instance for chaining. |
+
+#### `DispatcherViewThreadInvoker`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class DispatcherViewThreadInvoker` | Routes writes to a MAUI `BindableObject` through the dispatcher it carries. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `DispatcherViewThreadInvoker()` | Initializes a new instance of the DispatcherViewThreadInvoker class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `CheckAccess(object target)` | Returns whether the calling thread may write to the target; also true when the target has no dispatcher. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: A `BindableObject`; any other type throws [`InvalidCastException`](https://learn.microsoft.com/dotnet/api/system.invalidcastexception) | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `false` only when the target's dispatcher requires a dispatch from the calling thread. |
+| `Claims(object target)` | Determines whether this invoker handles `target`. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: The object a binding writes to | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` when the object belongs to this invoker's platform; otherwise `false`. |
+| `Post(object target, Action<object?> callback, object? state)` | Queues `callback` on the target's dispatcher, or runs it inline when the target has no dispatcher. | [`object`](https://learn.microsoft.com/dotnet/api/system.object) `target`: A `BindableObject`; any other type throws [`InvalidCastException`](https://learn.microsoft.com/dotnet/api/system.invalidcastexception); [`Action<object?>`](https://learn.microsoft.com/dotnet/api/system.action-1) `callback`: The callback to run; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `state`: The value passed to `callback` | — |
+
+#### `MauiBindingModule`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class MauiBindingModule` | Registers the MAUI view thread invoker, the Visibility converters and, in the WinUI build, the dependency-property observer with the dependency resolver. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `MauiBindingModule()` | Initializes a new instance of the MauiBindingModule class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `Configure(IMutableDependencyResolver resolver)` | Configures the specified dependency resolver with required services and components. | `IMutableDependencyResolver` `resolver`: The dependency resolver to configure. Cannot be null | — |
+
+#### `VisibilityToBooleanTypeConverter`
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `sealed class VisibilityToBooleanTypeConverter : BindingTypeConverter<Visibility, bool>` | Converts a [`Visibility`](https://learn.microsoft.com/dotnet/api/microsoft.maui.visibility) to a [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean), true for Visible and false for any other value; the conversion always succeeds. | None. | — |
+
+**Constructors**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `VisibilityToBooleanTypeConverter()` | Initializes a new instance of the VisibilityToBooleanTypeConverter class. | None. | — |
+
+**Methods**
+
+| Declaration | Description | Parameters | Returns |
+| --- | --- | --- | --- |
+| `override GetAffinityForObjects()` | Returns this converter's priority among the converters registered for the same type pair. | None. | [`int`](https://learn.microsoft.com/dotnet/api/system.int32): A positive value when the converter applies; zero or less excludes it. The highest value wins and the earliest registered converter wins a tie. The built-in converters return 2, and [`EqualityTypeConverter`](converters.md) returns 1, so a larger value outranks them. |
+| `override TryConvert(Visibility from, object? conversionHint, out bool result)` | Converts a value to the target type without boxing. | [`Visibility`](https://learn.microsoft.com/dotnet/api/microsoft.maui.visibility) `from`: The value to convert; [`object?`](https://learn.microsoft.com/dotnet/api/system.object) `conversionHint`: Implementation-defined hint for conversion (e.g., format string, locale); out [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean) `result`: The converted value. May be `null` when conversion succeeds for nullable targets | [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean): `true` if conversion succeeded; otherwise, `false`. |
diff --git a/docs/documentation/binding/bindings.md b/docs/documentation/binding/bindings.md
new file mode 100644
index 00000000..cb71603f
--- /dev/null
+++ b/docs/documentation/binding/bindings.md
@@ -0,0 +1,1934 @@
+---
+Order: 3
+---
+# Bindings
+
+[Run the complete page example](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/bindings/bindings.csproj).
+
+A screen shows data that lives in a view model. A label shows a count, a text box shows a filter and a button starts an action. Keeping each control in step with its property by hand takes an event handler for every pair, and you must remove each handler again.
+
+A **binding** is one call that connects two things and keeps them connected. The **view model** holds the data and the actions, and the **view** shows them. The **source** of a binding is the object it reads, and the **target** is the object it writes. A **one-way** binding writes from source to target. A **two-way** binding also writes an edit in the target back to the source. The page ends with how a binding fails and how to refuse one.
+
+| You want to | Call | It returns |
+| --- | --- | --- |
+| Copy a property one way | `BindOneWay` (source first), `OneWayBind` (view first) | `IDisposable`, or an `IReactiveBinding` |
+| Copy a property both ways | `BindTwoWay` (source first), `Bind` (view first) | `IDisposable`, or an `IReactiveBinding` |
+| Write a stream into a property | `BindTo` | `IDisposable` |
+| Attach a command to a control | `BindCommand` | `IDisposable` |
+| Run a command for each value of a stream | `InvokeCommand` | `IDisposable` |
+| Answer a question from the view model | `BindInteraction` | `IDisposable` |
+
+Every call takes its property paths as lambdas written inline, so the generator can read them at build time ([Your first binding](index.md#your-first-binding) shows the idea). Each call has an `Unsafe` twin for a lambda the generator cannot read, such as `BindOneWayUnsafe` and `BindCommandUnsafe`. [Unsafe twins and the runtime fallback](unsafe.md) lists them all. The examples use .NET MAUI controls built in code, and in-memory data.
+
+## Bind one property to another
+
+`BindOneWay` copies a property of a source object to a property of a target object. The value arrives when you create the binding and again after each change. The examples use an issue board: `IssueBoardViewModel` lists issues and holds the selected one, and `IssueBoardView` holds the controls.
+
+**1. Name the two properties.** The first lambda names the source property and the second names the target property. A lambda can be a **property path**, a chain of properties ([Observing](observing.md#follow-a-path-of-properties) covers paths). This path passes through `SelectedIssue`, which is `null` until the user picks an issue. The binding follows each link. While a link is `null` the label's `Text` stays `null`, and when `SelectedIssue` changes the binding moves to the new issue. `OpenIssueBoardAsync` loads the view model from the in-memory GitHub server.
+
+```csharp
+var board = await OpenIssueBoardAsync();
+IssueBoardView view = new();
+
+using (board.BindOneWay(view, x => x.SelectedIssue!.Title, v => v.IssueTitleLabel.Text))
+{
+    // The path passes through SelectedIssue, which is null until the user picks an issue.
+    Console.WriteLine(view.IssueTitleLabel.Text ?? NothingSelectedText);
+
+    board.SelectedIssue = board.Issues[CheckoutIssueIndex];
+    Console.WriteLine(view.IssueTitleLabel.Text);
+
+    board.SelectedIssue = board.Issues[0];
+    Console.WriteLine(view.IssueTitleLabel.Text);
+}
+```
+
+```text
+nothing selected
+Checkout button unresponsive on Safari
+Add gift-card support
+```
+
+**2. Convert when the types differ.** The plain overload needs the same type on both sides. When the types differ, pass a conversion function after the two lambdas. To show an enum in a `string` label, the function turns each state into text. Mark a function `static` when it uses nothing from the method around it.
+
+```csharp
+var board = await OpenIssueBoardAsync();
+IssueBoardView view = new();
+
+using (board.BindOneWay(view, x => x.SelectedIssue!.State, v => v.StateLabel.Text, static state => state == IssueState.Open ? OpenText : ClosedText))
+{
+    board.SelectedIssue = board.Issues[CheckoutIssueIndex];
+    Console.WriteLine(view.StateLabel.Text);
+
+    board.SelectedIssue.State = IssueState.Closed;
+    Console.WriteLine(view.StateLabel.Text);
+}
+```
+
+```text
+Open
+Closed
+```
+
+**3. Stop the binding.** `BindOneWay` returns an `IDisposable`. Dispose it when the view goes away. After that the label keeps the last text it was given. Dispose every binding you create: a live binding holds both objects in memory.
+
+```csharp
+var list = await OpenTodoListAsync();
+TodoView view = new();
+
+using (list.BindOneWay(view, x => x.RemainingCount, v => v.RemainingLabel.Text, static count => count.ToString(CultureInfo.InvariantCulture)))
+{
+    Console.WriteLine(view.RemainingLabel.Text);
+
+    list.SelectedItem = list.Items[0];
+    await list.CompleteAsync();
+    Console.WriteLine(view.RemainingLabel.Text);
+}
+
+// Disposing the binding disconnects it: the label keeps the last text it was given.
+list.SelectedItem = list.Items[CheckoutIssueIndex];
+await list.CompleteAsync();
+Console.WriteLine(view.RemainingLabel.Text);
+```
+
+```text
+3
+2
+2
+```
+
+## Bind from the view
+
+`OneWayBind` does the same work from the view's side. Call it on a view that implements `IViewFor` ([Views](views.md)) and pass the view model. It reads the view model and writes the view, and it returns an `IReactiveBinding` instead of an `IDisposable`. That object is a disposable that also reports what the binding writes, as [Read what a binding reports](#read-what-a-binding-reports) shows. A view-first call reads its view model from the view's `ViewModel` property, so set that property first.
+
+```csharp
+var list = await OpenTodoListAsync();
+TodoView view = new() { ViewModel = list };
+
+using (view.OneWayBind(list, x => x.FilterText, v => v.FilterTextBox.Text))
+{
+    list.FilterText = CarFilter;
+    Console.WriteLine(view.FilterTextBox.Text);
+}
+```
+
+```text
+car
+```
+
+Each call takes the same kinds of extra arguments, and each kind adds an overload.
+
+| Call | Reads | Writes | Extra arguments its overloads accept |
+| --- | --- | --- | --- |
+| `BindOneWay` | source | target | a conversion function, or a converter object with a hint; a sequencer |
+| `OneWayBind` | view model | view | a selector function, or a converter object with a hint; a sequencer |
+| `BindTwoWay` | source | target | one conversion function per direction, or two converter objects with a hint; a sequencer |
+| `Bind` | view model | view | the same as `BindTwoWay` |
+
+## Convert with a converter object
+
+A **converter object** implements `IBindingTypeConverter`. It converts one pair of types and can act on a **hint**, an extra value whose meaning the converter defines. Pass the object after the two lambdas, then the hint. A converter you name outranks every converter the library registers ([Converters](converters.md) lists them and [Custom converters](custom-converters.md) shows how to write one). `CurrencyTextConverter` in the example turns a `decimal` into text with a dollar sign. Its hint is the number format, and it shows two decimal places when you pass none.
+
+```csharp
+var accounts = await OpenAccountsAsync();
+AccountsView view = new();
+
+using (accounts.BindOneWay(view, x => x.TotalBalance, v => v.TotalBalanceLabel.Text, new CurrencyTextConverter(), GroupedFormat))
+{
+    Console.WriteLine(view.TotalBalanceLabel.Text);
+}
+```
+
+```text
+$17,681
+```
+
+`OneWayBind`, `BindTwoWay` and `Bind` take a converter object in the same way. A two-way call takes two, one for each direction, and the hint reaches both. The view-first `OneWayBind` below colours a badge from a priority. The hint names the dark theme.
+
+```csharp
+TodoItem item = new() { Title = ItemTitle, Priority = TodoPriority.High };
+TodoItemBadgeView view = new() { ViewModel = item };
+
+using (view.OneWayBind(item, x => x.Priority, v => v.PriorityBadge.Color, new PriorityColourConverter(), DarkThemeHint))
+{
+    Console.WriteLine(view.PriorityBadge.Color.ToArgbHex());
+
+    item.Priority = TodoPriority.Normal;
+    Console.WriteLine(view.PriorityBadge.Color.ToArgbHex());
+}
+```
+
+```text
+#EF5350
+#BDBDBD
+```
+
+A call that names a converter object is matched to its generated code by the file path and line number of the call. The generated match compares the path with forward slashes, and a Windows compiler writes backslashes. On Windows such a call reaches the library's own method and throws "No generated binding found", unless the build maps the source root with `PathMap`, for example `-p:PathMap=C:\src\=/_/`.
+
+## Choose when writes run
+
+A binding writes to its target on the thread that owns the target ([Threading and platforms](threading.md) explains how it finds that thread). To pick another place, pass a **sequencer** as the last argument. A sequencer decides when and on which thread queued work runs. `VirtualClock` in the example is a sequencer that runs its work only when the example calls `AdvanceBy`, so the example can show the write waiting. [Choose a sequencer for one binding](threading.md#deliver-a-binding-on-a-sequencer) shows how to choose one for your app.
+
+```csharp
+var board = await OpenIssueBoardAsync();
+IssueBoardView view = new();
+VirtualClock uiThread = new();
+
+using (board.BindOneWay(view, x => x.SelectedIssue!.Title, v => v.IssueTitleLabel.Text, uiThread))
+{
+    board.SelectedIssue = board.Issues[CheckoutIssueIndex];
+
+    Console.WriteLine($"Waiting: '{view.IssueTitleLabel.Text}'");
+
+    uiThread.AdvanceBy(NextTurn);
+
+    Console.WriteLine($"Written: '{view.IssueTitleLabel.Text}'");
+}
+```
+
+```text
+Waiting: ''
+Written: 'Checkout button unresponsive on Safari'
+```
+
+`BindOneWay`, `OneWayBind`, `BindTwoWay` and `Bind` all accept a sequencer, and it comes last. A `null` sequencer means the same as naming none: the write happens on the thread that owns the target, and a target with no owning thread is written at once. Name the argument, as in `scheduler: null` below, because a bare `null` also fits the string parameters of the overload that takes no sequencer.
+
+```csharp
+var board = await OpenIssueBoardAsync();
+IssueBoardView view = new();
+
+using (board.BindOneWay(view, x => x.SelectedIssue!.Title, v => v.IssueTitleLabel.Text, scheduler: null))
+{
+    board.SelectedIssue = board.Issues[CheckoutIssueIndex];
+    Console.WriteLine(view.IssueTitleLabel.Text);
+
+    board.SelectedIssue = board.Issues[0];
+    Console.WriteLine(view.IssueTitleLabel.Text);
+}
+```
+
+```text
+Checkout button unresponsive on Safari
+Add gift-card support
+```
+
+## Bind both ways
+
+`BindTwoWay` watches both properties and copies whichever one changes to the other. It also writes the source value to the target when you create the binding. Disposing the binding disconnects both directions.
+
+```csharp
+var list = await OpenTodoListAsync();
+TodoView view = new();
+
+using (list.BindTwoWay(view, x => x.FilterText, v => v.FilterTextBox.Text))
+{
+    list.FilterText = CarFilter;
+    Console.WriteLine(view.FilterTextBox.Text);
+
+    view.FilterTextBox.Text = DentistFilter;
+    Console.WriteLine(list.FilterText);
+    Console.WriteLine(list.Items.Count);
+}
+
+// Disposing the binding disconnects both directions.
+view.FilterTextBox.Text = string.Empty;
+Console.WriteLine(list.FilterText);
+
+list.FilterText = CarFilter;
+Console.WriteLine($"'{view.FilterTextBox.Text}'");
+```
+
+```text
+car
+dentist
+1
+dentist
+''
+```
+
+When the two types differ, pass one conversion function for each direction. `FormatAmount` writes a `decimal` as text and `ParseAmount` reads text back. The function for the return trip decides what an unusable value means: in the example, text that is not a number becomes `0`.
+
+```csharp
+TransferDraft draft = new() { Amount = RentAmount };
+TransferView view = new();
+
+using (draft.BindTwoWay(view, x => x.Amount, v => v.AmountTextBox.Text, FormatAmount, ParseAmount))
+{
+    Console.WriteLine(view.AmountTextBox.Text);
+
+    view.AmountTextBox.Text = TypedAmountText;
+    Console.WriteLine(draft.Amount);
+
+    // The reverse converter decides what text that is not a number means.
+    view.AmountTextBox.Text = NotAnAmountText;
+    Console.WriteLine(draft.Amount);
+}
+```
+
+```text
+1200.00
+85.50
+0
+```
+
+Converter objects come in pairs, one for each direction. The example uses the library's decimal converters and passes the number format as the hint.
+
+```csharp
+TransferDraft draft = new() { Amount = RentAmount };
+TransferView view = new();
+DecimalToStringTypeConverter toText = new();
+StringToDecimalTypeConverter toAmount = new();
+
+using (draft.BindTwoWay(view, x => x.Amount, v => v.AmountTextBox.Text, toText, toAmount, TwoDecimalPlaces))
+{
+    Console.WriteLine(view.AmountTextBox.Text);
+
+    view.AmountTextBox.Text = TypedAmountText;
+    Console.WriteLine(draft.Amount);
+}
+```
+
+```text
+1200.00
+85.50
+```
+
+A list holds its selection as an `object`, so a two-way binding to a selection converts in each direction. A one-way binding shows the selected title in a detail box.
+
+```csharp
+var viewModel = await OpenTodoListAsync();
+TodoView view = new() { ViewModel = viewModel };
+view.ItemsList.ItemsSource = viewModel.Items;
+
+// The list holds its selection as an object, so each direction converts.
+using (viewModel.BindTwoWay(view, x => x.SelectedItem, v => v.ItemsList.SelectedItem, static item => item, static selected => (selected as TodoItem)!))
+using (viewModel.BindOneWay(view, x => x.SelectedItem!.Title, v => v.SelectedTitleTextBox.Text))
+{
+    Console.WriteLine(view.SelectedTitleTextBox.Text ?? NothingSelectedText);
+
+    // The user clicks the second row.
+    var dentist = viewModel.Items[DentistIndex];
+    view.ItemsList.SelectedItem = dentist;
+
+    Console.WriteLine(ReferenceEquals(viewModel.SelectedItem, dentist));
+    Console.WriteLine(view.SelectedTitleTextBox.Text);
+
+    // Code selects the first item, and the list follows.
+    var renew = viewModel.Items[0];
+    viewModel.SelectedItem = renew;
+
+    Console.WriteLine(ReferenceEquals(view.ItemsList.SelectedItem, renew));
+    Console.WriteLine(view.SelectedTitleTextBox.Text);
+
+    // The box follows a change to the selected item itself.
+    renew.Title = RenamedTitle;
+
+    Console.WriteLine(view.SelectedTitleTextBox.Text);
+
+    // Clearing the selection in the list clears the detail.
+    view.ItemsList.SelectedItem = null;
+
+    Console.WriteLine(view.SelectedTitleTextBox.Text ?? NothingSelectedText);
+}
+```
+
+```text
+nothing selected
+True
+Book dentist appointment
+True
+Renew car registration
+Book dentist for a check-up
+nothing selected
+```
+
+[`ListSelectionBindingExamples`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/bindings/ListSelectionBindingExamples.cs) also binds a list of items, a busy indicator and a command that follows the selection.
+
+With a sequencer, both directions go through it. Only the newest value waits: an edit that a newer edit replaces before the sequencer runs is never written. Two edits made before the sequencer runs write once, with the second ([Only the latest value waits](threading.md#only-the-newest-value-waits) gives the reason).
+
+```csharp
+TransferDraft draft = new() { Reference = RentMarchReference };
+TransferView view = new();
+VirtualClock uiThread = new();
+
+using (draft.BindTwoWay(view, x => x.Reference, v => v.ReferenceTextBox.Text, uiThread))
+{
+    // The view is empty and the view model holds "Rent March": the view shows the view model once the sequencer runs.
+    Console.WriteLine($"Waiting: '{view.ReferenceTextBox.Text}'");
+
+    uiThread.AdvanceBy(NextTurn);
+    Console.WriteLine($"Written: '{view.ReferenceTextBox.Text}'");
+
+    draft.Reference = RentAprilReference;
+    draft.Reference = RentMayReference;
+    uiThread.AdvanceBy(NextTurn);
+
+    Console.WriteLine(view.ReferenceTextBox.Text);
+    Console.WriteLine(draft.Reference);
+}
+```
+
+```text
+Waiting: ''
+Written: 'Rent March'
+Rent May
+Rent May
+```
+
+`Bind` is the view-first form of `BindTwoWay`. It takes the same arguments in the same order and returns an `IReactiveBinding`. It writes back to the view model only while the view's `ViewModel` property is set. The example keeps the amount of a transfer draft equal to the amount box.
+
+```csharp
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+TransferView view = new() { ViewModel = viewModel };
+viewModel.Draft.Amount = RentAmount;
+
+using (view.Bind(viewModel, x => x.Draft.Amount, v => v.AmountTextBox.Text, FormatAmount, ParseAmount))
+{
+    Console.WriteLine(view.AmountTextBox.Text);
+
+    view.AmountTextBox.Text = TypedAmountText;
+    Console.WriteLine(viewModel.Draft.Amount);
+}
+```
+
+```text
+1200.00
+85.50
+```
+
+## Read what a binding reports
+
+A view-first call returns an `IReactiveBinding<TView, TValue>`. It disposes like any binding and it also carries these members.
+
+| Member | What it gives you |
+| --- | --- |
+| `View` | The view the binding writes. |
+| `Direction` | A `BindingDirection`: `OneWay`, `TwoWay` or `AsyncOneWay`. |
+| `Changed` | A stream of every value the binding writes. It starts with the current value. |
+| `ViewModelExpression`, `ViewExpression` | The two property expressions, or `null`. A generated binding reads its paths at build time, so it carries none. |
+
+`OneWayBind` reports each value it writes, such as a `double` for a progress bar, and its `Direction` is `OneWay`. `Changed` replays the bar's starting value, so the empty bar is the first value a subscriber sees.
+
+```csharp
+StorageBrowserViewModel browser = new(InMemoryObjectStorage.CreateSeeded());
+await browser.LoadBucketsAsync();
+browser.SelectedBucket = browser.Buckets[0];
+StorageBrowserView view = new() { ViewModel = browser };
+List<double> written = [];
+
+using (var binding = view.OneWayBind(browser, x => x.UploadPercent, v => v.UploadProgressBar.Progress, static percent => percent / PercentPerBar))
+{
+    Console.WriteLine(binding.Direction);
+    Console.WriteLine(ReferenceEquals(view, binding.View));
+
+    using (binding.Changed.Subscribe(written.Add))
+    {
+        await browser.UploadAsync(new("launch-video.mp4", UploadSizeBytes, "video/mp4"));
+    }
+}
+
+// Changed replays the bar's starting value, so the empty bar is the first value a subscriber sees.
+Console.WriteLine(string.Join(", ", written));
+```
+
+```text
+OneWay
+True
+0, 0.25, 0.5, 0.75, 1
+```
+
+`Bind` reports a `BindingChange` for each value. `BindingChange` is a record struct with two parts: the `Value` and `FromViewModel`, which tells an edit in the view apart from the echo of the binding's own write. The first change below came from the view model, and the second came from the box.
+
+```csharp
+var list = await OpenTodoListAsync();
+TodoView view = new() { ViewModel = list };
+List<BindingChange> changes = [];
+
+using (var binding = view.Bind(list, x => x.FilterText, v => v.FilterTextBox.Text))
+using (binding.Changed.Subscribe(changes.Add))
+{
+    Console.WriteLine(binding.Direction);
+    Console.WriteLine(ReferenceEquals(view, binding.View));
+
+    list.FilterText = CarFilter;
+    view.FilterTextBox.Text = DentistFilter;
+}
+
+foreach (var change in changes)
+{
+    Console.WriteLine($"{change.Value}, from the view model: {change.FromViewModel}");
+}
+```
+
+```text
+TwoWay
+True
+car, from the view model: True
+dentist, from the view model: False
+```
+
+You can build a `ReactiveBinding<TView, TValue>` yourself from a view, a stream of changes, a direction and the subscription that does the work. Disposing it disposes the subscription once, however often you call `Dispose`. The example builds one with `BindingDirection.AsyncOneWay`.
+
+```csharp
+var list = await OpenTodoListAsync();
+TodoView view = new() { ViewModel = list };
+Signal<int> remainingChanges = new();
+var subscription = Scope.Create(static () => Console.WriteLine("subscription disposed"));
+
+ReactiveBinding<TodoView, int> binding = new(view, remainingChanges, BindingDirection.AsyncOneWay, subscription);
+List<int> seen = [];
+using var reader = binding.Changed.Subscribe(seen.Add);
+
+remainingChanges.OnNext(list.RemainingCount);
+
+Console.WriteLine(binding.Direction);
+Console.WriteLine(ReferenceEquals(view, binding.View));
+Console.WriteLine(binding.ViewExpression is null);
+Console.WriteLine(binding.ViewModelExpression is null);
+Console.WriteLine(string.Join(", ", seen));
+
+binding.Dispose();
+binding.Dispose();
+```
+
+```text
+AsyncOneWay
+True
+True
+True
+3
+subscription disposed
+```
+
+## Choose when the view model updates
+
+A two-way binding writes each edit back at once. Sometimes the edit should wait, for example until the user leaves the box. `TriggerUpdate` names the direction that waits for a stream you supply. `ViewToViewModel` is the default: the typed value reaches the view model when the stream signals, and view model changes still reach the view at once. With `ViewModelToView` the first value reaches the view at once, and later view model changes wait for the stream.
+
+These triggers exist on the `BindUnsafe` overloads, which read their paths while the program runs. They are not safe for trimming, and they look up services, so run the builder once when the app starts. [Setup](setup.md) covers the builder, and [Unsafe twins and the runtime fallback](unsafe.md#hold-a-write-until-a-signal-fires) covers the triggers.
+
+```csharp
+IReactiveUIBindingBuilder builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+
+_ = builder.WithCoreServices().BuildApp();
+```
+
+The example commits the reference when the box loses focus. `boxLeft` is a `Signal<RxVoid>`, a stream that you feed with `OnNext`. `RxVoid` carries no data.
+
+```csharp
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+TransferView view = new() { ViewModel = viewModel };
+Signal<RxVoid> boxLeft = new();
+viewModel.Draft.Reference = MarchReference;
+
+using (view.BindUnsafe(viewModel, x => x.Draft.Reference, v => v.ReferenceTextBox.Text, boxLeft))
+{
+    Console.WriteLine(view.ReferenceTextBox.Text);
+
+    view.ReferenceTextBox.Text = AprilReference;
+    Console.WriteLine(viewModel.Draft.Reference);
+
+    boxLeft.OnNext(RxVoid.Default);
+    Console.WriteLine(viewModel.Draft.Reference);
+
+    viewModel.Draft.Reference = MayReference;
+    Console.WriteLine(view.ReferenceTextBox.Text);
+}
+```
+
+```text
+Rent March
+Rent March
+Rent April
+Rent May
+```
+
+Pass `TriggerUpdate.ViewModelToView` after the stream to hold back view model changes instead. Both triggers also come with a conversion function in each direction. Here the score reaches the box when the stream signals, and the teacher's typing reaches the view model at once.
+
+```csharp
+GradebookViewModel viewModel = new(InMemoryStudentRecords.CreateSeeded()) { ScoreToRecord = FirstScore };
+GradebookView view = new() { ViewModel = viewModel };
+Signal<RxVoid> refresh = new();
+
+using (view.BindUnsafe(viewModel, x => x.ScoreToRecord, v => v.ScoreEntry.Text, FormatScore, ParseScore, refresh, TriggerUpdate.ViewModelToView))
+{
+    Console.WriteLine(view.ScoreEntry.Text);
+
+    viewModel.ScoreToRecord = RemarkedScore;
+    Console.WriteLine(view.ScoreEntry.Text);
+
+    refresh.OnNext(RxVoid.Default);
+    Console.WriteLine(view.ScoreEntry.Text);
+
+    view.ScoreEntry.Text = TypedScoreText;
+    Console.WriteLine(viewModel.ScoreToRecord);
+}
+```
+
+```text
+64.0
+64.0
+91.0
+82.5
+```
+
+You can leave the converters out. Then the registered converter for the pair of types runs, and a pair of `string` properties passes the text through. The box stays empty until the stream signals, then shows the view model's value, and typing in the box still reaches the view model at once.
+
+```csharp
+var list = await OpenTodoListAsync();
+TodoView view = new() { ViewModel = list };
+Signal<RxVoid> refresh = new();
+
+using (view.BindUnsafe(list, x => x.FilterText, v => v.FilterTextBox.Text, refresh, TriggerUpdate.ViewModelToView))
+{
+    list.FilterText = CarFilter;
+    Console.WriteLine($"'{view.FilterTextBox.Text}'");
+
+    refresh.OnNext(RxVoid.Default);
+    Console.WriteLine(view.FilterTextBox.Text);
+
+    view.FilterTextBox.Text = DentistFilter;
+    Console.WriteLine(list.FilterText);
+}
+```
+
+```text
+''
+car
+dentist
+```
+
+Pass a `null` stream, cast to `IObservable<RxVoid>?`, and the binding observes both properties and writes in both directions as they change. The cast picks the overload.
+
+```csharp
+var list = await OpenTodoListAsync();
+TodoView view = new() { ViewModel = list };
+
+using (view.BindUnsafe(list, x => x.FilterText, v => v.FilterTextBox.Text, (IObservable<RxVoid>?)null))
+{
+    list.FilterText = CarFilter;
+    Console.WriteLine(view.FilterTextBox.Text);
+
+    view.FilterTextBox.Text = DentistFilter;
+    Console.WriteLine(list.FilterText);
+}
+```
+
+```text
+car
+dentist
+```
+
+The same works with converters, and with a stream that commits an amount when the box is left. [`ReactiveBindingExamples`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/bindings/ReactiveBindingExamples.cs) shows both.
+
+## Write a stream into a property
+
+`BindTo` is an extension of `IObservable<T>`. It writes each value of a stream to a property. Use it when the value comes from a stream that you built with an operator. The example turns the upload percentage into the fraction that a progress bar shows.
+
+`BindTo` hands each write to the thread that owns the target, so the stream needs no `ObserveOn`. When the value type differs from the property type, the converter registered for that pair runs ([Converters](converters.md)). When no converter is registered for the pair, such as an enum stream and a `string` property, `BindTo` writes nothing and reports nothing. Convert the value in the stream first, as `Select(state => state.ToString())` does.
+
+```csharp
+var browser = await OpenBucketAsync();
+StorageBrowserView view = new();
+
+using (browser.WhenChanged(x => x.UploadPercent).Select(static percent => percent / PercentPerBar).BindTo(view, v => v.UploadProgressBar.Progress))
+{
+    Console.WriteLine(view.UploadProgressBar.Progress);
+
+    await browser.UploadAsync(new("launch-video.mp4", UploadSizeBytes, "video/mp4"));
+    Console.WriteLine(view.UploadProgressBar.Progress);
+}
+```
+
+```text
+0
+1
+```
+
+`BindTo` has four overloads: the plain call, one with a converter to use instead of the registered ones, one with a conversion hint, and one with both. A hint that is a `string` would bind to the caller's expression parameter, so name the argument. The hint here is a number format.
+
+```csharp
+var accounts = await OpenAccountsAsync();
+AccountsView view = new();
+
+using (accounts.WhenChanged(x => x.TotalBalance).BindTo(view, v => v.TotalBalanceLabel.Text, conversionHint: GroupedFormat))
+{
+    Console.WriteLine(view.TotalBalanceLabel.Text);
+}
+```
+
+```text
+17,681
+```
+
+Sometimes the registered converters do not give the text you want. Name a converter to use it instead of every converter the library registers. Here `CurrencyTextConverter` adds a dollar sign to the balance.
+
+```csharp
+var accounts = await OpenAccountsAsync();
+AccountsView view = new();
+
+using (accounts.WhenChanged(x => x.TotalBalance).BindTo(view, v => v.TotalBalanceLabel.Text, new CurrencyTextConverter()))
+{
+    Console.WriteLine(view.TotalBalanceLabel.Text);
+}
+```
+
+```text
+$17,680.75
+```
+
+Pass the hint and the converter together when the converter needs a hint. The hint comes first. The converter in the example reads the hint as a number format, so the total loses its decimal places.
+
+```csharp
+var accounts = await OpenAccountsAsync();
+AccountsView view = new();
+
+using (accounts.WhenChanged(x => x.TotalBalance).BindTo(view, v => v.TotalBalanceLabel.Text, GroupedFormat, new CurrencyTextConverter()))
+{
+    Console.WriteLine(view.TotalBalanceLabel.Text);
+}
+```
+
+```text
+$17,681
+```
+
+A stream can come from an event. The example turns each `TextChanged` event of the filter box into the new text and writes it to the view model, so each text the user types narrows the list.
+
+```csharp
+var list = await OpenTodoListAsync();
+TodoView view = new();
+var typedTexts = Signal.FromEventPattern<TextChangedEventArgs>(handler => view.FilterTextBox.TextChanged += handler, handler => view.FilterTextBox.TextChanged -= handler)
+    .Select(static pattern => pattern.EventArgs.NewTextValue);
+
+using (typedTexts.BindTo(list, x => x.FilterText))
+{
+    Console.WriteLine(list.Items.Count);
+
+    view.FilterTextBox.Text = DentistFilter;
+
+    Console.WriteLine(list.FilterText);
+    Console.WriteLine(list.Items.Count);
+}
+```
+
+```text
+4
+dentist
+1
+```
+
+A value can arrive on a background thread, such as a socket callback. `BindTo` hands the write to the label's owning thread, so the stream needs no `ObserveOn`. A console process has no UI thread, so here the write runs where the value arrived.
+
+```csharp
+var storage = InMemoryObjectStorage.CreateSeeded();
+StorageBrowserViewModel browser = new(storage);
+StorageBrowserView view = new();
+var callerThread = Environment.CurrentManagedThreadId;
+
+using (browser.WhenChanged(x => x.ConnectionStatus)
+    .Do(state => Console.WriteLine($"{state} arrived on another thread: {Environment.CurrentManagedThreadId != callerThread}"))
+    .Select(static state => state.ToString())
+    .BindTo(view, v => v.ConnectionLabel.Text))
+{
+    // The connection drops on a thread of its own, as a socket callback does.
+    Thread socketThread = new(storage.Disconnect);
+    socketThread.Start();
+    socketThread.Join();
+
+    Console.WriteLine(view.ConnectionLabel.Text);
+}
+```
+
+```text
+Connected arrived on another thread: False
+Disconnected arrived on another thread: True
+Disconnected
+```
+
+## Bind a command to a control
+
+A **command** is an `ICommand`: an action with a `CanExecute` check. A view model exposes commands, and `BindCommand` attaches one to a control such as a button. It takes the view, the view model, a lambda for the command property and a lambda for the control. It rebinds when either the command or the control changes, and it binds nothing when the view model is `null`.
+
+For a MAUI `Button` the plain call attaches the command to the button, so the button follows `CanExecute`. The example add button is disabled until the new item has a title.
+
+```csharp
+TodoListViewModel viewModel = new(InMemoryTodoStore.CreateSeeded());
+await viewModel.LoadAsync();
+TodoView view = new() { ViewModel = viewModel };
+
+using var binding = view.BindCommand(viewModel, x => x.AddCommand, v => v.AddButton);
+
+Console.WriteLine(view.AddButton.IsEnabled);
+
+viewModel.NewTitle = NewTodoTitle;
+
+Console.WriteLine(view.AddButton.IsEnabled);
+```
+
+```text
+False
+True
+```
+
+Pass `toEvent` to bind through an event you name. The binding runs the command on each raise of the event and leaves the button's enabled state alone. Use it when the click, and not the enabled state, should decide when the command runs. The complete button below is bound through `Clicked`. Nothing is selected at first, so the command refuses the first click. The button stays enabled after the command runs.
+
+```csharp
+TodoListViewModel viewModel = new(InMemoryTodoStore.CreateSeeded());
+await viewModel.LoadAsync();
+TodoView view = new() { ViewModel = viewModel };
+
+using var binding = view.BindCommand(viewModel, x => x.CompleteCommand, v => v.CompleteButton, toEvent: ClickedEventName);
+
+// No item is selected, so the command refuses the click.
+((IButtonController)view.CompleteButton).SendClicked();
+
+Console.WriteLine(viewModel.RemainingCount);
+
+var item = viewModel.Items[0];
+viewModel.SelectedItem = item;
+var completed = item.WhenChanged(x => x.IsDone).Where(static done => done).FirstAsync();
+((IButtonController)view.CompleteButton).SendClicked();
+await completed;
+
+Console.WriteLine(viewModel.RemainingCount);
+Console.WriteLine(view.CompleteButton.IsEnabled);
+```
+
+```text
+3
+2
+True
+```
+
+A command can take a **parameter**, the value that `Execute` and `CanExecute` receive. `BindCommand` never picks a parameter for you. A plain call passes none, so an event-driven control runs the command with `null`. A control that has its own `CommandParameter` property keeps the value it already holds, because the plain call sets only its `Command`. To supply a parameter, use one of two more overloads. Each also accepts `toEvent`.
+
+- **A stream.** The parameter is the latest value the stream produced. It is `null` until the first value arrives.
+- **A lambda on the view model.** The parameter is that property, and the binding follows every value the property takes.
+
+A control with settable `Command` and `CommandParameter` properties, such as a MAUI `Button`, receives the parameter in its `CommandParameter` property. The binding writes the parameter before the command. The other kinds of control keep the latest parameter and pass it to `CanExecute` and `Execute` when the event fires. The enrol button below passes the student selected in a candidate list.
+
+```csharp
+GradebookViewModel viewModel = new(InMemoryStudentRecords.CreateSeeded());
+await viewModel.LoadCoursesAsync();
+viewModel.SelectedCourse = viewModel.Courses[MathCourseIndex];
+await viewModel.OpenCourseAsync();
+GradebookView view = new() { ViewModel = viewModel };
+view.CandidateList.ItemsSource = viewModel.Candidates.ToList();
+
+using var binding = view.BindCommand(viewModel, x => x.EnrolCommand, v => v.EnrolButton, view.CandidateList.WhenChanged(x => x.SelectedItem));
+
+Console.WriteLine(view.EnrolButton.IsEnabled);
+
+view.CandidateList.SelectedItem = viewModel.Candidates[DiegoCandidateIndex];
+
+Console.WriteLine(view.EnrolButton.IsEnabled);
+
+var rosterLoaded = viewModel.WhenChanged(x => x.Roster).Skip(1).FirstAsync();
+((IButtonController)view.EnrolButton).SendClicked();
+await rosterLoaded;
+
+Console.WriteLine(viewModel.Roster.Count);
+```
+
+```text
+False
+True
+3
+```
+
+The stream form takes `toEvent` too. Here each file the user picks is a value of a `Signal`, and the button is bound through `Clicked`.
+
+```csharp
+var browser = await OpenPhotosFolderAsync();
+StorageBrowserView view = new() { ViewModel = browser };
+Signal<UploadRequest> pickedFiles = new();
+
+using var binding = view.BindCommand(browser, x => x.UploadCommand, v => v.UploadButton, pickedFiles, toEvent: ClickedEventName);
+
+pickedFiles.OnNext(SpringCampaign());
+var uploaded = browser.WhenChanged(x => x.IsUploading).Skip(1).Where(static uploading => !uploading).FirstAsync();
+((IButtonController)view.UploadButton).SendClicked();
+await uploaded;
+
+Console.WriteLine(browser.Objects.Count);
+```
+
+```text
+3
+```
+
+The other overload takes a lambda on the view model, and the parameter is that property. The upload button stays disabled until a file is picked, and the pick reaches the command as its parameter.
+
+```csharp
+var browser = await OpenPhotosFolderAsync();
+UploadPanelViewModel viewModel = new(browser);
+UploadPanelView view = new() { ViewModel = viewModel };
+
+using var binding = view.BindCommand(viewModel, x => x.UploadCommand, v => v.UploadButton, x => x.PendingUpload);
+
+Console.WriteLine(view.UploadButton.IsEnabled);
+
+viewModel.PendingUpload = SpringCampaign();
+
+Console.WriteLine(view.UploadButton.IsEnabled);
+
+var uploaded = browser.WhenChanged(x => x.IsUploading).Skip(1).Where(static uploading => !uploading).FirstAsync();
+((IButtonController)view.UploadButton).SendClicked();
+await uploaded;
+
+Console.WriteLine(browser.Objects.Count);
+Console.WriteLine(browser.Objects[SpringCampaignPosition].Key);
+```
+
+```text
+False
+True
+3
+photos/2026/spring-campaign.png
+```
+
+The lambda form takes `toEvent` in the same way. Use it when the click, and not the button's enabled state, should decide when the command runs. The view model's `PendingUpload` property supplies the parameter.
+
+```csharp
+var browser = await OpenPhotosFolderAsync();
+UploadPanelViewModel viewModel = new(browser);
+UploadPanelView view = new() { ViewModel = viewModel };
+
+using var binding = view.BindCommand(viewModel, panel => panel.UploadCommand, v => v.UploadButton, panel => panel.PendingUpload, toEvent: ClickedEventName);
+
+viewModel.PendingUpload = SpringCampaign();
+var uploaded = browser.WhenChanged(x => x.IsUploading).Skip(1).Where(static uploading => !uploading).FirstAsync();
+((IButtonController)view.UploadButton).SendClicked();
+await uploaded;
+
+Console.WriteLine(browser.Objects.Count);
+```
+
+```text
+3
+```
+
+Which overload to use depends on how the controls come about. When a few fixed controls share one command, such as a row of buttons that each add a different amount, bind each control with its own parameter stream. When the controls are generated from a collection, give each item a view model with the value as a property, and bind that property with the lambda form. Each row then reads its own value.
+
+Every kind of control the generator knows about supports a bound parameter. The generator picks a mechanism by the shape of the control, so a control on another platform works when it has one of these shapes.
+
+| Shape of the control | How the command runs | How the parameter arrives |
+| --- | --- | --- |
+| A settable `Command` and `CommandParameter` (MAUI, WPF and WinUI buttons) | The control runs its own command | Written to `CommandParameter` before `Command` |
+| A `Click`, `TouchUpInside` or `Pressed` event and an `Enabled` property (WinForms controls) | The binding handles the event | Passed to `CanExecute` and `Execute` |
+| A `Click`, `TouchUpInside` or `Pressed` event and no `Enabled` property | The binding handles the event | Passed to `CanExecute` and `Execute` |
+| An Android `View` | The binding handles `Click` | Passed to `CanExecute` and `Execute` |
+| A UIKit `UIControl`, `UIRefreshControl` or `UIBarButtonItem` | The binding handles a touch, `ValueChanged` or `Clicked` | Passed to `CanExecute` and `Execute` |
+| A Cocoa control with a target and action | The binding sets the target and action | Read when the control fires |
+
+Only the MAUI row runs in the examples. The other rows follow from the generator's source.
+
+Each `BindCommand` call is its own binding, and it returns an `IDisposable`. Disposing it removes the handler from the control's event and stops the binding from watching the command. Suppose you make a binding with `toEvent` and never dispose it. Its handler stays subscribed for as long as the control lives. A long-lived view should dispose it when the view goes away. Bind one button twice, with and without `toEvent`, and both bindings reach the command. The plain binding attaches the command to the button and follows `CanExecute`. The event binding runs the command on each click. After `clicked.Dispose()` a press still reaches the command through the plain binding, and the count rises by one instead of two.
+
+```csharp
+StatementExportViewModel viewModel = new() { HasStatement = true };
+StatementExportView view = new() { ViewModel = viewModel };
+
+var attached = view.BindCommand(viewModel, x => x.ExportCommand, v => v.ExportButton);
+var clicked = view.BindCommand(viewModel, x => x.ExportCommand, v => v.ExportButton, toEvent: ClickedEventName);
+
+Console.WriteLine(ReferenceEquals(viewModel.ExportCommand, view.ExportButton.Command));
+
+// One press reaches the command through both bindings.
+((IButtonController)view.ExportButton).SendClicked();
+
+Console.WriteLine(viewModel.ExportCount);
+
+clicked.Dispose();
+((IButtonController)view.ExportButton).SendClicked();
+
+Console.WriteLine(viewModel.ExportCount);
+
+// Only the plain binding follows CanExecute, so the button goes dark while no statement is chosen.
+viewModel.HasStatement = false;
+
+Console.WriteLine(view.ExportButton.IsEnabled);
+
+attached.Dispose();
+```
+
+```text
+True
+2
+3
+False
+``` The analyzer reports RXUIBIND007 when the control has no event to bind ([Setup](setup.md#understand-the-analyzers)). On WPF and WinForms, raise `CanExecuteChanged` on the thread that owns the button. A command that changes its state on a pool thread throws on WPF ([Threading and platforms](threading.md)).
+
+### Choose how a control gets its command
+
+An `ICreatesCommandBinding` decides how a command reaches a control. The runtime asks every registered binder how well it fits the control and uses the one with the highest score, its **affinity**. A score of `0` means the binder cannot bind the control ([Mechanisms](mechanisms.md#write-a-command-binder) shows how to write and register one). The example binder, `ClickedCommandBinder`, scores a MAUI `Button` at `10` and any other control at `0`. Ask a binder for its score with `GetAffinityForObject`.
+
+```csharp
+var binder = ChooseBinder();
+
+Console.WriteLine(binder.GetAffinityForObject<Button>(hasEventTarget: false));
+Console.WriteLine(binder.GetAffinityForObject<Entry>(hasEventTarget: false));
+```
+
+```text
+10
+0
+```
+
+A binder has three `BindCommandToObject` methods. Each returns an `IDisposable` that detaches the command. The [example file](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/bindings/CreatesCommandBindingExamples.cs) calls all three. The first binds the control's default event. Disposing the result detaches the command.
+
+```csharp
+StatementExportViewModel viewModel = new() { HasStatement = true };
+StatementExportView view = new();
+var binder = ChooseBinder();
+
+using (binder.BindCommandToObject(viewModel.ExportCommand, view.ExportButton, Signal.Never<object?>()))
+{
+    ((IButtonController)view.ExportButton).SendClicked();
+
+    Console.WriteLine(viewModel.ExportCount);
+}
+
+((IButtonController)view.ExportButton).SendClicked();
+
+Console.WriteLine(viewModel.ExportCount);
+```
+
+```text
+1
+1
+```
+
+The second binds an event by name, which is what `toEvent` reaches. It returns `null` for an event the binder does not know, so check the result. The example asks for `Clicked`, which the binder knows, and for `Pressed`, which it does not.
+
+```csharp
+StatementExportViewModel viewModel = new() { HasStatement = true };
+StatementExportView view = new();
+var binder = ChooseBinder();
+
+using var clicked = binder.BindCommandToObject<Button, EventArgs>(viewModel.ExportCommand, view.ExportButton, Signal.Never<object?>(), ClickedEventName);
+var pressed = binder.BindCommandToObject<Button, EventArgs>(viewModel.ExportCommand, view.ExportButton, Signal.Never<object?>(), PressedEventName);
+
+((IButtonController)view.ExportButton).SendClicked();
+
+Console.WriteLine(viewModel.ExportCount);
+Console.WriteLine(pressed is null);
+```
+
+```text
+The binder is asked for the Clicked event, which carries EventArgs
+The binder is asked for the Pressed event, which carries EventArgs
+1
+True
+```
+
+The third takes the add and remove handlers for an event. Use it when you know the event at build time, because no reflection then finds the event. The example runs a search command each time the filter box raises `TextChanged`, and stops once the binding is disposed.
+
+```csharp
+TodoView view = new();
+var binder = ChooseBinder();
+Command search = new(static () => Console.WriteLine("search"));
+var entry = view.FilterTextBox;
+
+using (binder.BindCommandToObject<Entry, TextChangedEventArgs>(
+    search,
+    entry,
+    Signal.Never<object?>(),
+    handler => entry.TextChanged += handler,
+    handler => entry.TextChanged -= handler))
+{
+    entry.Text = CarFilter;
+}
+
+entry.Text = string.Empty;
+```
+
+```text
+search
+```
+
+`BindCommandUnsafe` asks the registered binders for the control's event. When none fits the control, nothing is attached. The MAUI package registers no binder, so register your own for the controls you use.
+
+## Run a command for each value
+
+`InvokeCommand` runs a command with each value of a stream, and the value is the command's parameter. It asks the command's `CanExecute` first and drops a value the command refuses. It does not queue the value for later. An error in the stream is rethrown on the thread that raised it, and completion is ignored. Disposing the returned `IDisposable` stops the runs.
+
+The example runs the sign-in command each time the access token changes. A blank token is refused by the command and dropped.
+
+```csharp
+IssueBoardViewModel viewModel = new(InMemoryGitHubServer.CreateSeeded());
+
+using var subscription = viewModel.WhenChanged(x => x.Token).InvokeCommand(viewModel.SignInCommand);
+
+viewModel.Token = "   ";
+
+Console.WriteLine(viewModel.IsSignedIn);
+Console.WriteLine(viewModel.RateLimitRemaining);
+
+var loaded = viewModel.WhenChanged(x => x.Repositories).Where(static repositories => repositories.Count > 0).FirstAsync();
+viewModel.Token = InMemoryGitHubServer.PriyaToken;
+await loaded;
+
+Console.WriteLine(viewModel.IsSignedIn);
+```
+
+```text
+False
+60
+True
+```
+
+A second overload takes an object and a lambda for a command property, and it reads the command from the property. A `null` command drops the values offered while it stands. A later command takes over from the next value, and replacing the command runs nothing by itself. Below, choosing a repository loads its issues.
+
+```csharp
+var viewModel = await SignInAsync();
+
+using var subscription = viewModel.WhenChanged(x => x.SelectedRepository!).InvokeCommand(viewModel, x => x.LoadIssuesCommand);
+
+Console.WriteLine(viewModel.Issues.Count);
+
+var loaded = viewModel.WhenChanged(x => x.RateLimitRemaining).Skip(1).FirstAsync();
+viewModel.SelectedRepository = viewModel.Repositories[0];
+await loaded;
+
+Console.WriteLine(viewModel.Issues.Count);
+```
+
+```text
+0
+2
+```
+
+The [example file](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/bindings/InvokeCommandExamples.cs) also drives a command from a timer and skips the ticks that arrive while a refresh runs. It loads the next page when the last row appears, and it runs a command once at start-up.
+
+## Answer a question from the view model
+
+A view model sometimes needs an answer from the user, such as "Close this issue?". It has no business showing a dialog. An **interaction** lets it ask without knowing the UI. The view model owns an `Interaction<TInput, TOutput>` and calls `Handle` with the input. The view registers a **handler**, a method that shows the dialog and calls `SetOutput` with the answer. `Handle` returns that answer.
+
+`BindInteraction` registers a handler on the interaction that a view model property holds. The handler receives an `IInteractionContext<TInput, TOutput>` with the `Input` and the `SetOutput` method. Register a handler that returns a `Task`, and the question stays open until the task ends. In the example the close waits for the dialog.
+
+```csharp
+var viewModel = await OpenWebshopIssuesAsync();
+IssueBoardView view = new() { ViewModel = viewModel };
+TaskCompletionSource<bool> dialog = new(TaskCreationOptions.RunContinuationsAsynchronously);
+
+using var binding = view.BindInteraction(viewModel, x => x.ConfirmClose, async context => context.SetOutput(await dialog.Task));
+
+var issue = viewModel.Issues[0];
+viewModel.SelectedIssue = issue;
+var closing = viewModel.CloseIssueAsync();
+
+Console.WriteLine(closing.IsCompleted);
+Console.WriteLine(issue.State);
+
+dialog.SetResult(true);
+await closing;
+
+Console.WriteLine(issue.State);
+```
+
+```text
+False
+Open
+Closed
+```
+
+A handler can also return an `IObservable<T>`. The interaction moves on when the observable completes, ignores its values and treats a fault in it as a fault of `Handle`. The teacher below confirms a drop only on the second try.
+
+```csharp
+GradebookViewModel viewModel = new(InMemoryStudentRecords.CreateSeeded());
+await viewModel.LoadCoursesAsync();
+viewModel.SelectedCourse = viewModel.Courses[0];
+await viewModel.OpenCourseAsync();
+viewModel.SelectedStudent = viewModel.Roster[BenRosterIndex];
+GradebookView view = new() { ViewModel = viewModel };
+var teacherConfirms = false;
+
+using var binding = view.BindInteraction(viewModel, x => x.ConfirmDrop, context =>
+{
+    context.SetOutput(teacherConfirms);
+    return Signal.Return(context.Input.Student.Id);
+});
+
+await viewModel.DropAsync();
+
+Console.WriteLine(viewModel.Roster.Count);
+
+teacherConfirms = true;
+await viewModel.DropAsync();
+
+Console.WriteLine(viewModel.Roster.Count);
+```
+
+```text
+3
+2
+```
+
+The property can have the type `IInteraction<TInput, TOutput>`, the interface that `Interaction<TInput, TOutput>` implements. `BindInteraction` accepts either.
+
+```csharp
+var board = await OpenWebshopIssuesAsync();
+IssueTriageViewModel viewModel = new(board);
+IssueTriageView view = new() { ViewModel = viewModel };
+
+using var binding = view.BindInteraction(viewModel, x => x.ConfirmClose, static context =>
+{
+    context.SetOutput(context.Input.State == IssueState.Open);
+    return Task.CompletedTask;
+});
+
+var issue = board.Issues[0];
+board.SelectedIssue = issue;
+await board.CloseIssueAsync();
+
+Console.WriteLine(issue.State);
+```
+
+```text
+Closed
+```
+
+Disposing the binding removes its handler, so the next question goes unanswered. The first question below is answered. The second throws `UnhandledInteractionException`.
+
+```csharp
+var viewModel = await OpenWebshopIssuesAsync();
+IssueBoardView view = new() { ViewModel = viewModel };
+var issue = viewModel.Issues[0];
+var binding = view.BindInteraction(viewModel, x => x.ConfirmClose, static context =>
+{
+    context.SetOutput(false);
+    return Task.CompletedTask;
+});
+
+Console.WriteLine(await viewModel.ConfirmClose.Handle(issue));
+
+binding.Dispose();
+
+var unanswered = false;
+try
+{
+    _ = await viewModel.ConfirmClose.Handle(issue);
+}
+catch (UnhandledInteractionException<Issue, bool>)
+{
+    unanswered = true;
+}
+
+Console.WriteLine(unanswered);
+```
+
+```text
+False
+True
+```
+
+A view often exists before its view model does. In that case `BindInteraction` registers nothing and does not throw, and disposing the result is safe. The handler below never runs.
+
+```csharp
+IssueBoardView view = new();
+IssueBoardViewModel? viewModel = null;
+var handlerRuns = 0;
+
+var binding = view.BindInteraction(viewModel, x => x.ConfirmClose, context =>
+{
+    handlerRuns++;
+    context.SetOutput(true);
+    return Task.CompletedTask;
+});
+
+binding.Dispose();
+
+Console.WriteLine(handlerRuns);
+```
+
+```text
+0
+```
+
+A screen can bind two interactions in turn. The bank confirms a large transfer, and then asks the view for a one-time code.
+
+```csharp
+var (viewModel, view) = await OpenTransferScreenAsync();
+
+using var confirmation = view.BindInteraction(viewModel, x => x.ConfirmTransfer, static context =>
+{
+    Console.WriteLine("confirm");
+    context.SetOutput(true);
+    return Task.CompletedTask;
+});
+
+using var approval = view.BindInteraction(viewModel, x => x.ApproveTransfer, static context =>
+{
+    Console.WriteLine("approve");
+    context.SetOutput(InMemoryBankingBackend.ApprovalCode);
+    return Task.CompletedTask;
+});
+
+FillLargeTransfer(viewModel);
+await viewModel.TransferAsync();
+
+Console.WriteLine(viewModel.LastReceipt!.Amount);
+```
+
+```text
+confirm
+approve
+1200
+```
+
+### Register handlers on the interaction
+
+`Interaction<TInput, TOutput>` has three `RegisterHandler` overloads. One takes an `Action`, one takes a method that returns a `Task`, and one takes a method that returns an `IObservable<T>`. Each returns an `IDisposable` that removes the handler. `IInteraction<TInput, TOutput>` declares the same three methods and `Handle`. The example below uses only the interface. It registers each kind of handler, asks a question and removes a handler.
+
+```csharp
+IssueTriageViewModel triage = new(new(InMemoryGitHubServer.CreateSeeded()));
+var confirmClose = triage.ConfirmClose;
+Issue issue = new() { Number = CheckoutIssueNumber };
+using var declines = confirmClose.RegisterHandler(static context => context.SetOutput(false));
+using var asksAgain = confirmClose.RegisterHandler(static context => Signal.Return(context.IsHandled));
+var confirms = confirmClose.RegisterHandler(static context =>
+{
+    context.SetOutput(true);
+    return Task.CompletedTask;
+});
+
+Console.WriteLine(await confirmClose.Handle(issue));
+
+confirms.Dispose();
+
+Console.WriteLine(await confirmClose.Handle(issue));
+```
+
+```text
+True
+False
+```
+
+Handlers run in reverse order of registration: the handler registered last answers first. A handler need not answer. When it does not call `SetOutput`, the interaction offers the question to the next handler. Below, the handler in the middle ignores the question and the latest one answers. Disposing the latest registration hands the question to the first.
+
+```csharp
+Interaction<TransferDraft, string> approval = new();
+TransferDraft draft = new();
+using var first = approval.RegisterHandler(static context => context.SetOutput(FirstAnswer));
+using var ignoring = approval.RegisterHandler(static context => Signal.Return(context.IsHandled));
+var latest = approval.RegisterHandler(static context =>
+{
+    context.SetOutput(LatestAnswer);
+    return Task.CompletedTask;
+});
+
+Console.WriteLine(await approval.Handle(draft));
+
+latest.Dispose();
+
+Console.WriteLine(await approval.Handle(draft));
+```
+
+```text
+latest
+first
+```
+
+### Read the context
+
+Every handler receives the same context object for one question. `IInteractionContext<TInput, TOutput>` gives the `Input`, `IsHandled` and `SetOutput`. The class behind it, `InteractionContext<TInput, TOutput>`, also implements `IOutputContext<TInput, TOutput>`, which adds `GetOutput`. `IsHandled` is `false` until a handler sets the output. Reading the output early, or setting it a second time, throws `InvalidOperationException`. The handler below casts the context to `InteractionContext` and reads the members in order.
+
+```csharp
+Interaction<Issue, bool> confirmClose = new();
+Issue issue = new() { Number = CheckoutIssueNumber };
+
+using var registration = confirmClose.RegisterHandler(static context =>
+{
+    var answer = (InteractionContext<Issue, bool>)context;
+
+    Console.WriteLine(answer.Input.Number);
+    Console.WriteLine(answer.IsHandled);
+
+    answer.SetOutput(true);
+
+    Console.WriteLine(answer.IsHandled);
+    Console.WriteLine(answer.GetOutput());
+});
+
+Console.WriteLine(await confirmClose.Handle(issue));
+```
+
+```text
+101
+False
+True
+True
+True
+```
+
+The next example checks the rules. It casts the context to `IOutputContext` and tries to read the output before it is set, and to set it twice. Each attempt is refused.
+
+```csharp
+Interaction<Issue, bool> confirmClose = new();
+Issue issue = new() { Number = CheckoutIssueNumber };
+Issue? receivedInput = null;
+var handledBefore = true;
+var handledAfter = false;
+var isInteractionContext = false;
+var earlyReadRefused = false;
+var readBack = false;
+var secondAnswerRefused = false;
+
+using var registration = confirmClose.RegisterHandler(context =>
+{
+    receivedInput = context.Input;
+    handledBefore = context.IsHandled;
+    isInteractionContext = context is InteractionContext<Issue, bool>;
+
+    var output = (IOutputContext<Issue, bool>)context;
+    earlyReadRefused = RefusesWithInvalidOperation(() => output.GetOutput());
+
+    context.SetOutput(true);
+    handledAfter = context.IsHandled;
+    readBack = output.GetOutput();
+    secondAnswerRefused = RefusesWithInvalidOperation(() => context.SetOutput(false));
+});
+
+var answer = await confirmClose.Handle(issue);
+
+Console.WriteLine(ReferenceEquals(issue, receivedInput));
+Console.WriteLine(handledBefore);
+Console.WriteLine(handledAfter);
+Console.WriteLine(isInteractionContext);
+Console.WriteLine(earlyReadRefused);
+Console.WriteLine(readBack);
+Console.WriteLine(secondAnswerRefused);
+Console.WriteLine(answer);
+```
+
+```text
+True
+False
+True
+True
+True
+True
+True
+True
+```
+
+### Handle a question that nobody answers
+
+When no handler answers, `Handle` throws `UnhandledInteractionException<TInput, TOutput>`. It carries the `Input` and the `Interaction` that asked.
+
+```csharp
+var viewModel = await OpenWebshopIssuesAsync();
+var issue = viewModel.Issues[0];
+viewModel.SelectedIssue = issue;
+UnhandledInteractionException<Issue, bool>? failure = null;
+
+try
+{
+    await viewModel.CloseIssueAsync();
+}
+catch (UnhandledInteractionException<Issue, bool> ex)
+{
+    failure = ex;
+}
+
+Console.WriteLine(failure is not null);
+Console.WriteLine(failure!.Message);
+Console.WriteLine(ReferenceEquals(issue, failure.Input));
+Console.WriteLine(ReferenceEquals(viewModel.ConfirmClose, failure.Interaction));
+Console.WriteLine(issue.State);
+```
+
+```text
+True
+Failed to find a registration for an Interaction.
+True
+True
+Open
+```
+
+The exception has four constructors. They take nothing, a message, a message and an inner exception, or the interaction and its input. The last builds the standard message above. The example calls each one and reads back what it holds.
+
+```csharp
+Interaction<Issue, bool> confirmClose = new();
+Issue issue = new() { Number = CheckoutIssueNumber };
+InvalidOperationException cause = new("The dialog host has shut down.");
+
+UnhandledInteractionException<Issue, bool> empty = new();
+UnhandledInteractionException<Issue, bool> withMessage = new(NobodyAnswersMessage);
+UnhandledInteractionException<Issue, bool> withCause = new(NobodyAnswersMessage, cause);
+UnhandledInteractionException<Issue, bool> forQuestion = new(confirmClose, issue);
+
+Console.WriteLine(empty.Interaction is null);
+Console.WriteLine(withMessage.Message);
+Console.WriteLine(ReferenceEquals(cause, withCause.InnerException));
+Console.WriteLine(forQuestion.Message);
+Console.WriteLine(ReferenceEquals(confirmClose, forQuestion.Interaction));
+Console.WriteLine(ReferenceEquals(issue, forQuestion.Input));
+```
+
+```text
+True
+Nobody answers close confirmations.
+True
+Failed to find a registration for an Interaction.
+True
+True
+```
+
+### Derive your own interaction
+
+`Interaction<TInput, TOutput>` is not sealed. Override `Handle` to wrap a question, call `GetHandlers` to read the registered handlers in order of registration, and override `GenerateContext` to wrap the context each handler receives. `AuditedInteraction` writes each question and answer to the console, as a bank keeps an audit trail of an approval.
+
+```csharp
+public override async Task<TOutput> Handle(TInput input)
+{
+    Console.WriteLine($"ask {input} of {GetHandlers().Length} handlers");
+    return await base.Handle(input).ConfigureAwait(false);
+}
+
+protected override IOutputContext<TInput, TOutput> GenerateContext(TInput input) => new AuditingOutputContext<TInput, TOutput>(base.GenerateContext(input));
+```
+
+## When a binding fails
+
+A write can fail: a converter throws, a setter refuses a value, or the stream that feeds the write ends in an error. A failed write has no caller to report to, because it arrives on whichever thread raised the change. `BindingErrors` sets the rules that every binding follows.
+
+- Every fault is logged against the bound expression.
+- A fault that carries an inner exception, such as a setter that threw, is rethrown as a `TargetInvocationException`. The exception names the expression and holds the cause.
+- A fault with no inner exception is only logged, because the stream itself ended in error. A stream that has ended writes nothing more.
+- Completion is ignored.
+
+The log entries go to a logger registered with the service locator. Without one you see nothing. The example registers a logger that writes each entry to the console, so the later examples can print them.
+
+```csharp
+AppLocator.CurrentMutable.RegisterConstant<ILogger>(new ConsoleLogger { ExceptionMessageFormat = "{0}" });
+```
+
+Generated code calls `BindingErrors.Subscribe`, and you can call it yourself. It takes a stream, the write and the bound expression. The example feeds the three cases through it: values, a fault without a cause and a fault with one.
+
+```csharp
+List<string> written = [];
+Signal<string> values = new();
+Signal<string> withoutCause = new();
+Signal<string> withCause = new();
+InvalidOperationException cause = new(CauseMessage);
+
+using (BindingErrors.Subscribe(values, written.Add, BoundExpression))
+using (BindingErrors.Subscribe(withoutCause, written.Add, BoundExpression))
+using (BindingErrors.Subscribe(withCause, written.Add, BoundExpression))
+{
+    values.OnNext(ShortReference);
+    values.OnCompleted();
+
+    Console.WriteLine(string.Join(", ", written));
+
+    // A fault with no cause is logged.
+    withoutCause.OnError(new InvalidOperationException(ConversionMessage));
+
+    // A fault with a cause is logged and rethrown, wrapped with the bound expression.
+    try
+    {
+        withCause.OnError(new InvalidOperationException(ConversionMessage, cause));
+    }
+    catch (TargetInvocationException ex)
+    {
+        Console.WriteLine(ReferenceEquals(cause, ex.InnerException));
+        Console.WriteLine(ex.Message.Contains(BoundExpression, StringComparison.Ordinal));
+    }
+}
+```
+
+```text
+Rent March
+LogHost: x => x.Reference Binding received an Exception! (OnError)
+LogHost: x => x.Reference Binding received an Exception! (OnError)
+True
+True
+```
+
+A setter that throws does so on the thread that raised the change, so the exception reaches whoever changed the view model property. A binding created over a bad value throws while it is created. The example target refuses a reference longer than 18 characters, and both cases throw an `ArgumentException`.
+
+```csharp
+TransferDraft draft = new() { Reference = ShortReference };
+StatementReferenceView field = new();
+
+using (draft.BindOneWay(field, x => x.Reference, v => v.Reference))
+{
+    Console.WriteLine(field.Reference);
+
+    try
+    {
+        draft.Reference = LongReference;
+    }
+    catch (ArgumentException ex)
+    {
+        Console.WriteLine(ex.Message);
+    }
+}
+
+Console.WriteLine(field.Reference);
+
+try
+{
+    using var second = draft.BindOneWay(field, x => x.Reference, v => v.Reference);
+}
+catch (ArgumentException ex)
+{
+    Console.WriteLine(ex.Message);
+}
+```
+
+```text
+Rent March
+A statement reference has at most 18 characters. (Parameter 'value')
+Rent March
+A statement reference has at most 18 characters. (Parameter 'value')
+```
+
+A real binding follows the same rules. When the converter throws with no inner exception, the binding logs the fault and rethrows nothing. The faulted stream has ended, so the label writes nothing more.
+
+```csharp
+TransferDraft draft = new() { Reference = ShortReference };
+Label label = new();
+
+using (draft.BindOneWay(label, x => x.Reference, v => v.Text, static reference => reference == ForbiddenReference ? throw new InvalidOperationException(ConversionMessage) : reference))
+{
+    Console.WriteLine(label.Text);
+
+    draft.Reference = ForbiddenReference;
+
+    // The faulted sequence has ended, so the binding writes nothing more.
+    draft.Reference = ShortReference;
+    Console.WriteLine(label.Text);
+    draft.Reference = AprilReference;
+    Console.WriteLine(label.Text);
+}
+```
+
+```text
+Rent March
+LogHost: v => v.Text Binding received an Exception! (OnError)
+Rent March
+Rent March
+```
+
+When the converter throws with an inner exception, the binding logs the fault and rethrows it as a `TargetInvocationException` that names the bound expression and carries the cause.
+
+```csharp
+TransferDraft draft = new() { Reference = ShortReference };
+Label label = new();
+InvalidOperationException cause = new(CauseMessage);
+
+using (draft.BindOneWay(label, x => x.Reference, v => v.Text, reference => reference == ForbiddenReference ? throw new InvalidOperationException(ConversionMessage, cause) : reference))
+{
+    try
+    {
+        draft.Reference = ForbiddenReference;
+    }
+    catch (TargetInvocationException ex)
+    {
+        Console.WriteLine(ReferenceEquals(cause, ex.InnerException));
+        Console.WriteLine(ex.Message);
+    }
+}
+```
+
+```text
+LogHost: v => v.Text Binding received an Exception! (OnError)
+True
+v => v.Text Binding received an Exception!
+```
+
+## Refuse a binding with a hook
+
+A **hook** looks at a binding as it is created and can refuse it. Write a class that implements `IPropertyBindingHook` and register it with the service locator. Its `ExecuteHook` method receives the source, the target, two methods that read the current values of each side, and the `BindingDirection`. Return `false` to cancel the binding. The hook below refuses every two-way binding whose source is the accounts view model.
+
+```csharp
+public bool ExecuteHook(
+    object? source,
+    object target,
+    Func<IObservedChange<object, object>[]> getCurrentViewModelProperties,
+    Func<IObservedChange<object, object>[]> getCurrentViewProperties,
+    BindingDirection direction)
+{
+    if (source is not AccountsViewModel || direction != BindingDirection.TwoWay)
+    {
+        return true;
+    }
+
+    Console.WriteLine("read-only: refused a two-way binding");
+    return false;
+}
+```
+
+`BindOneWay`, `BindTwoWay`, `OneWayBind` and `Bind` each ask the hooks once. A refused binding that returns an `IDisposable` returns an empty one, and nothing is written to the view. A refused view-first binding returns `null`, so check for `null` before you use the result. One-way bindings pass this hook, as the second call below shows.
+
+```csharp
+var accounts = await OpenAccountsAsync();
+AccountNameView view = new() { ViewModel = accounts };
+
+AppLocator.CurrentMutable.RegisterConstant<IPropertyBindingHook>(new ReadOnlyAccountHook());
+BindingHooks.Refresh();
+
+var refused = view.Bind(accounts, x => x.SelectedAccount!.Name, v => v.NameTextBox.Text);
+using var allowed = view.OneWayBind(accounts, x => x.SelectedAccount!.Name, v => v.NameTextBox.Text);
+
+Console.WriteLine(refused is null);
+Console.WriteLine(allowed is null);
+Console.WriteLine(view.NameTextBox.Text);
+```
+
+```text
+read-only: refused a two-way binding
+True
+False
+Everyday Account
+```
+
+`BindingHooks` holds the registered hooks. `BindingHooks.Any` says whether any hook exists. A binding tests it first, so an application with no hook pays nothing. `BindingHooks.ShouldBind` asks the hooks in turn and stops at the first refusal, so a hook after a refusing hook is never asked. Bindings call it for you, and you call it yourself only to test a hook.
+
+Most applications register no hook. `BindingHooks.Any` is then `false` and a binding asks nobody, so the check costs almost nothing. The example prints `Any` and binds one property.
+
+```csharp
+var accounts = await OpenAccountsAsync();
+AccountNameView view = new();
+
+Console.WriteLine(BindingHooks.Any);
+
+using (accounts.BindOneWay(view, x => x.SelectedAccount!.Name, v => v.NameTextBox.Text))
+{
+    Console.WriteLine(view.NameTextBox.Text);
+}
+```
+
+```text
+False
+Everyday Account
+```
+
+The next example registers a hook that writes down every binding. Each of the four binding methods asks the hook once, with its direction.
+
+```csharp
+var accounts = await OpenAccountsAsync();
+AccountNameView view = new() { ViewModel = accounts };
+
+AppLocator.CurrentMutable.RegisterConstant<IPropertyBindingHook>(new LoggingBindingHook("log"));
+BindingHooks.Refresh();
+
+Console.WriteLine(BindingHooks.Any);
+
+using (accounts.BindOneWay(view, x => x.SelectedAccount!.Name, v => v.NameTextBox.Text))
+using (accounts.BindTwoWay(view, x => x.SelectedAccount!.Name, v => v.NameTextBox.Text))
+using (view.OneWayBind(accounts, x => x.SelectedAccount!.Name, v => v.NameTextBox.Text))
+using (view.Bind(accounts, x => x.SelectedAccount!.Name, v => v.NameTextBox.Text))
+{
+    Console.WriteLine("all four bound");
+}
+
+RemoveHooks();
+```
+
+```text
+True
+log: OneWay: AccountsViewModel -> AccountNameView
+log: TwoWay: AccountsViewModel -> AccountNameView
+log: OneWay: AccountsViewModel -> AccountNameView
+log: TwoWay: AccountsViewModel -> AccountNameView
+all four bound
+```
+
+A refused source-first binding returns an empty disposable. Here the hook refuses `BindTwoWay`, so the box shows nothing and an edit never reaches the account. Once the hook is gone the same binding writes the edit.
+
+```csharp
+var accounts = await OpenAccountsAsync();
+AccountNameView view = new();
+var everydayName = accounts.SelectedAccount!.Name;
+
+AppLocator.CurrentMutable.RegisterConstant<IPropertyBindingHook>(new ReadOnlyAccountHook());
+BindingHooks.Refresh();
+
+using (accounts.BindTwoWay(view, x => x.SelectedAccount!.Name, v => v.NameTextBox.Text))
+{
+    // The refused binding is an empty disposable: nothing was written to the view either.
+    Console.WriteLine($"'{view.NameTextBox.Text}'");
+
+    view.NameTextBox.Text = RenamedEverydayName;
+    Console.WriteLine(accounts.SelectedAccount.Name == everydayName);
+}
+
+// One-way bindings pass the hook.
+using (accounts.BindOneWay(view, x => x.SelectedAccount!.Name, v => v.NameTextBox.Text))
+{
+    Console.WriteLine(view.NameTextBox.Text);
+}
+
+RemoveHooks();
+
+// With the hook gone the same two-way binding writes the edit to the account.
+using (accounts.BindTwoWay(view, x => x.SelectedAccount!.Name, v => v.NameTextBox.Text))
+{
+    view.NameTextBox.Text = RenamedEverydayName;
+    Console.WriteLine(accounts.SelectedAccount.Name);
+}
+```
+
+```text
+read-only: refused a two-way binding
+''
+True
+Everyday Account
+Household Account
+```
+
+You can ask the hooks yourself with `BindingHooks.ShouldBind`. The example registers three hooks. The first and third only log, and the second refuses a two-way binding. The one-way question reaches all three. The two-way question stops at the second, so the third is never asked.
+
+```csharp
+var accounts = await OpenAccountsAsync();
+AccountNameView view = new();
+
+AppLocator.CurrentMutable.RegisterConstant<IPropertyBindingHook>(new LoggingBindingHook("first"));
+AppLocator.CurrentMutable.RegisterConstant<IPropertyBindingHook>(new ReadOnlyAccountHook());
+AppLocator.CurrentMutable.RegisterConstant<IPropertyBindingHook>(new LoggingBindingHook("last"));
+BindingHooks.Refresh();
+
+var oneWay = BindingHooks.ShouldBind(accounts, view, Observed(accounts), Observed(view), BindingDirection.OneWay);
+var twoWay = BindingHooks.ShouldBind(accounts, view, Observed(accounts), Observed(view), BindingDirection.TwoWay);
+
+Console.WriteLine(oneWay);
+Console.WriteLine(twoWay);
+
+RemoveHooks();
+```
+
+```text
+first: OneWay: AccountsViewModel -> AccountNameView
+last: OneWay: AccountsViewModel -> AccountNameView
+first: TwoWay: AccountsViewModel -> AccountNameView
+read-only: refused a two-way binding
+True
+False
+```
+
+`BindingHooks` reads the registrations once and keeps them. Register every hook before the first binding, or call `BindingHooks.Refresh` after you register one. The example below registers a hook late. The first binding does not ask it, and the binding after `Refresh` does.
+
+```csharp
+var accounts = await OpenAccountsAsync();
+AccountNameView view = new();
+
+Console.WriteLine(BindingHooks.Any);
+
+AppLocator.CurrentMutable.RegisterConstant<IPropertyBindingHook>(new LoggingBindingHook("late"));
+
+// The hook is registered, but the registrations were read before it arrived, so this binding does not ask it.
+using (accounts.BindOneWay(view, x => x.SelectedAccount!.Name, v => v.NameTextBox.Text))
+{
+    Console.WriteLine("bound without the hook");
+}
+
+BindingHooks.Refresh();
+
+Console.WriteLine(BindingHooks.Any);
+
+using (accounts.BindOneWay(view, x => x.SelectedAccount!.Name, v => v.NameTextBox.Text))
+{
+    Console.WriteLine("bound with the hook");
+}
+
+RemoveHooks();
+
+Console.WriteLine(BindingHooks.Any);
+```
+
+```text
+False
+bound without the hook
+True
+late: OneWay: AccountsViewModel -> AccountNameView
+bound with the hook
+False
+```
+
+You can also call a hook's `ExecuteHook` yourself with values you build. This is how you test a hook without creating a binding. The logging hook always agrees, and the read-only hook refuses a two-way binding.
+
+```csharp
+AccountsViewModel accounts = new(new InMemoryBankingBackend());
+AccountNameView view = new();
+
+Console.WriteLine(AskHook(new LoggingBindingHook("audit"), accounts, view, BindingDirection.OneWay));
+Console.WriteLine(AskHook(new ReadOnlyAccountHook(), accounts, view, BindingDirection.OneWay));
+Console.WriteLine(AskHook(new ReadOnlyAccountHook(), accounts, view, BindingDirection.TwoWay));
+```
+
+```text
+audit: OneWay: AccountsViewModel -> AccountNameView
+True
+True
+read-only: refused a two-way binding
+False
+```
+
+## Next steps
+
+- [Observing](observing.md) watches properties without writing them anywhere.
+- [Converters](converters.md) lists the converters a binding picks by itself, and [Custom converters](custom-converters.md) writes your own.
+- [Threading and platforms](threading.md) explains the owning thread and the sequencers.
+- [Unsafe twins and the runtime fallback](unsafe.md) covers a call the generator cannot read.
+- [API reference](api.md) lists every public member with its parameters.
+
+## API reference
+
+Each binding call has several overloads, and one row covers all of them. The generic-parameter lists and the compiler-filled `callerFilePath` and `callerLineNumber` parameters are in the [API reference](api.md).
+
+| Member | What it does | Type and values | Notes |
+| --- | --- | --- | --- |
+| [`BindOneWay`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.Binding.cs) | Copies a source property to a target property one way. It writes the current value and each later change. | Extension method on a source object of a class type. Returns `IDisposable`. Overloads add a conversion function, or a converter object with an optional hint. | The overloads that take a sequencer are in [ReactiveSchedulerExtensions.cs](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveSchedulerExtensions.cs). The plain overload needs the same type on both sides. A hook that refuses the binding leaves nothing bound. |
+| [`OneWayBind`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.Binding.cs) | Copies a view model property to a view property one way. | Extension method on a view that implements `IViewFor`. Returns `IReactiveBinding<TView, TVProp>`. Overloads add a selector function, or a converter object with an optional hint, and a sequencer. | Returns `null` when a hook refuses the binding. Reads the view model you pass, so set the view's `ViewModel` first. |
+| [`BindTwoWay`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.Binding.cs) | Keeps a source property and a target property equal. It seeds the target from the source, then copies each change to the other side. | Extension method on a source object of a class type. Returns `IDisposable`. Overloads add one conversion function per direction, or two converter objects with an optional hint, and a sequencer. | Disposing disconnects both directions. A hook that refuses the binding leaves nothing bound. A sequencer holds only the newest value. |
+| [`Bind`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.Binding.cs) | The view-first form of `BindTwoWay`. It keeps a view model property and a view property equal. | Extension method on a view that implements `IViewFor`. Returns `IReactiveBinding<TView, BindingChange>`. Takes the same extra arguments as `BindTwoWay`. | Returns `null` when a hook refuses the binding. Writes back to the view model only while the view's `ViewModel` is set. |
+| [`BindTo`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.BindTo.cs) | Writes each value of a stream to a target property. | Extension method on `IObservable<TValue>`. Returns `IDisposable`. Four overloads: plain, converter override, conversion hint, and hint with converter override. | Writes on the target's owning thread when its platform has one. When no converter matches the two types, it writes nothing and reports nothing. Name a `string` hint as `conversionHint:`. |
+| [`BindCommand`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.BindCommand.cs) | Attaches the command a view model property holds to a control on the view. | Extension method on a view that implements `IViewFor`. Returns `IDisposable`. Three overloads: no parameter, a stream parameter, or a view model property parameter. Each takes an optional `toEvent`. | Binds nothing when the view model is `null`. Rebinds when the command or the control changes. A `null` `toEvent` selects the control's default event. Never picks a parameter for you. |
+| [`InvokeCommand`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.InvokeCommand.cs) | Runs a command with each value of a stream as its parameter. | Extension method on `IObservable<T>`. Returns `IDisposable`. Two overloads: a fixed `ICommand`, or an object and a lambda for a command property. | Drops a value the command refuses, and does not queue it. The property form drops values while the command is `null`, and executes nothing when the object is `null`. |
+| [`BindInteraction`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.BindInteraction.cs) | Registers a handler on the interaction a view model property holds. | Extension method on a view that implements `IViewFor`. Returns `IDisposable`. Two overloads: a handler that returns `Task`, or one that returns `IObservable<T>`. | Moves the handler to the new interaction when the property changes. Registers nothing when the view model is `null`. Disposing removes the handler. |
+| [`IInteraction<TInput, TOutput>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/IInteraction.cs) | A question the view model asks and a view answers. | Interface. Members: `Handle` and `RegisterHandler`. | `Interaction<TInput, TOutput>` implements it. |
+| [`IInteraction.Handle`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/IInteraction.cs) | Asks the question and returns the answer. | Takes `TInput`. Returns `Task<TOutput>`. | Completes with the output that a handler sets. |
+| [`IInteraction.RegisterHandler`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/IInteraction.cs) | Adds a handler. | Three overloads: `Action`, a method that returns `Task`, and a method that returns `IObservable<TDontCare>`. Returns `IDisposable`. | Disposing the result removes the handler. |
+| [`IInteractionContext<TInput, TOutput>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/IInteractionContext.cs) | The object a handler receives for one question. | Interface. Members: `Input`, `IsHandled` and `SetOutput`. | Every handler of one question receives the same object. |
+| [`IInteractionContext.Input`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/IInteractionContext.cs) | The value the view model asked about. | Read-only `TInput`. | |
+| [`IInteractionContext.IsHandled`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/IInteractionContext.cs) | Says whether a handler has set the output. | Read-only `bool`. | `false` until `SetOutput` runs. |
+| [`IInteractionContext.SetOutput`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/IInteractionContext.cs) | Answers the question. | Takes `TOutput`. Returns nothing. | A second call throws `InvalidOperationException`. |
+| [`IOutputContext<TInput, TOutput>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/IOutputContext.cs) | Adds the ability to read the answer. | Interface that extends `IInteractionContext<TInput, TOutput>`. Member: `GetOutput`. | `Interaction<TInput, TOutput>.GenerateContext` returns this type. |
+| [`IOutputContext.GetOutput`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/IOutputContext.cs) | Reads the answer. | Returns `TOutput`. | Throws `InvalidOperationException` before a handler sets the output. |
+| [`Interaction<TInput, TOutput>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/Interaction.cs) | The class a view model owns to ask questions. | Non-sealed class that implements `IInteraction<TInput, TOutput>`. | Handlers run in reverse order of registration. Derive from it to wrap `Handle` or the context. |
+| [`Interaction()`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/Interaction.cs) | Creates an interaction with no handlers. | Public constructor with no parameters. | |
+| [`Interaction.Handle`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/Interaction.cs) | Runs the handlers, latest registered first, until one sets an output. | Virtual. Takes `TInput`. Returns `Task<TOutput>`. | Throws `UnhandledInteractionException<TInput, TOutput>` when no handler sets an output. |
+| [`Interaction.RegisterHandler`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/Interaction.cs) | Adds a handler. | Three overloads, as on `IInteraction`. Returns `IDisposable`. | A handler that returns an observable finishes when the observable completes. A fault in the observable faults `Handle`. A `null` handler throws `ArgumentNullException`. |
+| [`Interaction.GetHandlers`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/Interaction.cs) | Reads the registered handlers. | Protected. Returns an array of `Func<IInteractionContext<TInput, TOutput>, Task>`. | A copy, earliest registered first. |
+| [`Interaction.GenerateContext`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/Interaction.cs) | Creates the context every handler receives for one `Handle` call. | Protected virtual. Takes `TInput`. Returns `IOutputContext<TInput, TOutput>`. | Override it to wrap the context. |
+| [`InteractionContext<TInput, TOutput>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/InteractionContext.cs) | The default context. It holds the input and the answer. | Sealed class that implements `IOutputContext<TInput, TOutput>`. Has `Input`, `IsHandled`, `SetOutput` and `GetOutput`. | The constructor is internal, so you receive it from `Handle`. Setting the output twice throws `InvalidOperationException`. |
+| [`UnhandledInteractionException<TInput, TOutput>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/UnhandledInteractionException.cs) | Reports a question that no handler answered. | Class that derives from `Exception`. Four constructors: none, a message, a message and an inner exception, or an interaction and its input. | The last constructor sets the message to "Failed to find a registration for an Interaction." |
+| [`UnhandledInteractionException.Input`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/UnhandledInteractionException.cs) | The input of the question that went unanswered. | Read-only `TInput`. | The default value when the exception was built without an input. |
+| [`UnhandledInteractionException.Interaction`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interactions/UnhandledInteractionException.cs) | The interaction that went unanswered. | Read-only `Interaction<TInput, TOutput>?`. | `null` when the exception was built without an interaction. |
+| [`BindingChange`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingChange.cs) | A value a two-way binding moved, and which side produced it. | Readonly record struct with a constructor `(object? Value, bool FromViewModel)`. | Compares, deconstructs and copies like any record struct. |
+| [`BindingChange.Value`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingChange.cs) | The value that was written. | `object?`, settable in an object initializer. | Can be `null`. |
+| [`BindingChange.FromViewModel`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingChange.cs) | Says whether the view model produced the value. | `bool`, settable in an object initializer. | `false` means the view produced it. Tells an edit apart from the echo of the binding's own write. |
+| [`BindingDirection`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/BindingDirection.cs) | Names the direction of a binding. | Enum: `OneWay`, `TwoWay`, `AsyncOneWay`. | Read from `IReactiveBinding.Direction` and passed to hooks. |
+| [`BindingDirection.OneWay = 0`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/BindingDirection.cs) | One way, from source to target. | `0` | |
+| [`BindingDirection.TwoWay = 1`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/BindingDirection.cs) | Both ways, between source and target. | `1` | |
+| [`BindingDirection.AsyncOneWay = 2`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/BindingDirection.cs) | One way, from source to target, delivered asynchronously. | `2` | |
+| [`IReactiveBinding<TView, TValue>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IReactiveBinding.cs) | A binding between a view and a view model property. | Interface that extends `IDisposable`. `TView` must implement `IViewFor`. | Returned by `OneWayBind` and `Bind`. |
+| [`IReactiveBinding.Changed`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IReactiveBinding.cs) | A stream of the values the binding writes. | Read-only `IObservable<TValue>`. | Starts with the current value. |
+| [`IReactiveBinding.Direction`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IReactiveBinding.cs) | The direction of the binding. | Read-only `BindingDirection`. | |
+| [`IReactiveBinding.View`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IReactiveBinding.cs) | The view the binding writes. | Read-only `TView`. | |
+| [`IReactiveBinding.ViewExpression`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IReactiveBinding.cs) | The expression of the bound view property. | Read-only `Expression?`. | `null` when the binding carries none. A generated binding carries none. |
+| [`IReactiveBinding.ViewModelExpression`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IReactiveBinding.cs) | The expression of the bound view model property. | Read-only `Expression?`. | `null` when the binding carries none. A generated binding carries none. |
+| [`ReactiveBinding<TView, TValue>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/ReactiveBinding.cs) | The standard `IReactiveBinding` that generated view-first bindings return. | Sealed class. Constructor `(TView view, IObservable<TValue> changed, BindingDirection direction, IDisposable subscription)`. | `ViewExpression` and `ViewModelExpression` are always `null`. |
+| [`ReactiveBinding.Dispose`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/ReactiveBinding.cs) | Disposes the subscription. | Returns nothing. | Acts on the first call only. Later calls do nothing. |
+| [`BindingHooks`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingHooks.cs) | Lets registered hooks inspect, or refuse, a binding as it is created. | Static class. Members: `Any`, `Refresh` and `ShouldBind`. | The service locator is read on first use, and the hooks are cached until `Refresh`. |
+| [`BindingHooks.Any`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingHooks.cs) | Says whether any hook was registered when the hooks were last read. | Read-only `bool`. | A binding tests it first, so an application with no hook pays nothing. |
+| [`BindingHooks.Refresh`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingHooks.cs) | Discards the cached hooks so the next use reads them again. | Returns nothing. | Call it after you register a hook late. |
+| [`BindingHooks.ShouldBind`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingHooks.cs) | Asks the hooks in turn whether a binding may be created. | Takes the source (`object?`), the target, two functions that read the current values of each side, and a `BindingDirection`. Returns `bool`. Hidden from IntelliSense. | Stops at the first refusal. Returns `true` when no hook is registered. Throws `ArgumentNullException` for a `null` target or `null` functions. |
+| [`IPropertyBindingHook`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IPropertyBindingHook.cs) | A class you write to look at, or cancel, a binding as it is created. | Interface with one method, `ExecuteHook`. | Register it with the service locator. |
+| [`IPropertyBindingHook.ExecuteHook`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IPropertyBindingHook.cs) | Called as a binding is set up, before anything is wired. | Takes the source (`object?`), the target, two functions that read the current values of each side, and a `BindingDirection`. Returns `bool`. | Return `false` to cancel the binding. |
+| [`BindingErrors`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingErrors.cs) | Sets how a binding reacts when the stream that feeds its write faults. | Static class. Member: `Subscribe`. | A fault is logged. A fault with an inner exception is rethrown as `TargetInvocationException`. Completion is ignored. |
+| [`BindingErrors.Subscribe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingErrors.cs) | Subscribes a write to its source and applies those rules. | Takes an `IObservable<T>`, an `Action<T>` and the bound expression as a `string`. Returns `IDisposable`. Hidden from IntelliSense. | Throws `ArgumentNullException` for a `null` source or `null` write. Disposing disconnects the write. |
diff --git a/docs/documentation/binding/converters.md b/docs/documentation/binding/converters.md
new file mode 100644
index 00000000..decd5495
--- /dev/null
+++ b/docs/documentation/binding/converters.md
@@ -0,0 +1,775 @@
+---
+Order: 4
+---
+# Converters
+
+[Run the complete page example](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/converters/converters.csproj).
+
+A binding often joins two properties of different types. A text box holds a `string`. The view model holds an `int`. A converter turns a value of one type into a value of another. The binding calls it each time a value crosses from one side to the other.
+
+ReactiveUI.Binding ships converters for the common pairs: text to and from numbers, dates, times, durations, booleans, GUIDs and URIs. Each one also has a nullable form. You rarely call a converter yourself, because a binding finds the right one. The examples on this page call them directly, because that shows what each converter accepts and what it rejects. Writing your own converter belongs on [Custom converters](custom-converters.md).
+
+Four terms carry the page.
+
+- A **converter** is a class with a source type and a target type. `StringToIntegerTypeConverter` reads a `string` and produces an `int`.
+- A **conversion hint** is an optional `object` that you pass with the value. Each converter decides what a hint means. Most ignore it.
+- An **affinity** is an `int` that a converter reports for its type pair. When several converters serve the same pair, the highest affinity wins. Every built-in converter reports 2, except `EqualityTypeConverter`, which reports 1.
+- The **converter service** is the table of converters that bindings look in. `BindingConverters.Current` holds it.
+
+The examples set the current culture to the invariant culture, so their output is the same on every machine. In your own app the converters use the current culture. The output below shows the invariant form.
+
+## Convert one value
+
+**1. Choose the converter for the type pair.** Converter names follow one pattern: `StringToIntegerTypeConverter` converts from `string` to `int`, and `IntegerToStringTypeConverter` converts back. A converter holds no state. Create one with `new`.
+
+**2. Call `TryConvert`.** Pass the value, the conversion hint and an `out` variable for the result. The call returns `true` when the conversion worked. It returns `false` when it did not, and the `out` variable then holds the default of the target type. A converter reports a bad value through the return value and does not throw. Pass `null` as the hint when you have none. The excerpt below converts one good text and one bad text, so you see both results.
+
+```csharp
+var converter = new StringToIntegerTypeConverter();
+
+// Success case: valid issue number
+var success = converter.TryConvert("42", conversionHint: null, out var issueNumber);
+Console.WriteLine(success);
+Console.WriteLine(issueNumber);
+
+// Failure case: non-numeric input
+var failure = converter.TryConvert(InvalidNumberText, conversionHint: null, out var failResult);
+Console.WriteLine(failure);
+Console.WriteLine(failResult);
+```
+
+The text `not-a-number` fails. The result is `0`, the default `int`.
+
+```text
+True
+42
+False
+0
+```
+
+**3. Convert back for display.** A converter for the opposite direction turns the `int` into text for a label. Converting a number to text always succeeds. The excerpt formats an issue number and a zero, so you see the text a label would show.
+
+```csharp
+var converter = new IntegerToStringTypeConverter();
+
+// Success case: display issue number
+var success = converter.TryConvert(IssueNumber, conversionHint: null, out var issueText);
+Console.WriteLine(success);
+Console.WriteLine(issueText);
+
+// Success case: no issues
+_ = converter.TryConvert(0, conversionHint: null, out var noIssuesText);
+Console.WriteLine(noIssuesText);
+```
+
+```text
+True
+42
+0
+```
+
+**4. Let the binding find the converter.** When the two properties of a binding have different types, the binding converts through the converter service. It looks for the converter of that exact pair of types. You write no converter code. A binding can also take conversion functions in place of a converter object, one function for each direction of a two-way binding. [Bindings](bindings.md) shows the binding calls and both ways to convert.
+
+## The converter contract
+
+Every built-in converter implements the same members. The table names them and says where each one comes from.
+
+| Member | Declared on | What it does |
+| --- | --- | --- |
+| `FromType` | `IBindingTypeConverter` | The source type. |
+| `ToType` | `IBindingTypeConverter` | The target type. |
+| `GetAffinityForObjects()` | `IBindingTypeConverter` | The priority among converters for the same pair. Zero or less excludes the converter. |
+| `TryConvertTyped(object?, object?, out object?)` | `IBindingTypeConverter` | Converts a boxed value. |
+| `TryConvert(TFrom?, object?, out TTo?)` | `IBindingTypeConverter<TFrom, TTo>` | Converts a value of the source type, with no boxing. |
+
+`BindingTypeConverter<TFrom, TTo>` is the base class of every converter on this page except two. It supplies `FromType`, `ToType` and `TryConvertTyped`. `TryConvertTyped` returns `false` when the value is not a `TFrom`. It also returns `false` for `null` when `TFrom` is a value type that cannot hold null.
+
+`StringConverter` and `EqualityTypeConverter` implement `IBindingTypeConverter` directly. They have no typed `TryConvert`. You call `TryConvertTyped` on them, as [String and equality](#string-and-equality) shows.
+
+## What success and failure mean
+
+Each group of converters treats a bad value or a `null` the same way.
+
+- **Text to a value type**, such as `StringToIntegerTypeConverter`. `null` and text that does not parse return `false`.
+- **Text to a nullable type**, such as `StringToNullableIntegerTypeConverter`. `null` and an empty string succeed with a `null` result. Text that does not parse returns `false`.
+- **A value type to text.** The conversion succeeds.
+- **A nullable type to text.** The conversion succeeds. A `null` value gives a `null` string.
+- **A value type to its nullable form.** The conversion succeeds.
+- **A nullable type to its value type.** A `null` value returns `false`.
+
+A generated binding treats `false` as "no value to write". It writes nothing for that value, and the target keeps the value it has. The binding stays connected, so the next value is converted as usual. It logs nothing and throws nothing. The same happens when no converter serves the pair of types.
+
+One case differs. Suppose you passed no converter of your own, and the source type can be assigned to the target type. Then a value that a registered converter declines is assigned as it is. A `null` `string` bound to a `string` property is one example: `StringConverter` declines it, and the target receives `null`. A converter that throws is a different case, which [Bindings](bindings.md#when-a-binding-fails) explains.
+
+A numeric converter to text also takes a hint. An `int` hint sets the minimum digit count for a whole number, or the number of decimal places for `float`, `double` and `decimal`. A `string` hint is a .NET format string. A malformed format string throws `FormatException`.
+
+## Numbers
+
+Seven numeric types have a converter in each direction. The parse converters use the `TryParse` method of their type under the current culture. A value outside the range of the target type fails.
+
+| Type | Text to number | Number to text |
+| --- | --- | --- |
+| `byte` | `StringToByteTypeConverter` | `ByteToStringTypeConverter` |
+| `short` | `StringToShortTypeConverter` | `ShortToStringTypeConverter` |
+| `int` | `StringToIntegerTypeConverter` | `IntegerToStringTypeConverter` |
+| `long` | `StringToLongTypeConverter` | `LongToStringTypeConverter` |
+| `float` | `StringToSingleTypeConverter` | `SingleToStringTypeConverter` |
+| `double` | `StringToDoubleTypeConverter` | `DoubleToStringTypeConverter` |
+| `decimal` | `StringToDecimalTypeConverter` | `DecimalToStringTypeConverter` |
+
+The range check matters for the small types. A port number is a `short`, so `99999` does not fit. `TryConvert` returns `false` and does not wrap around. The excerpt parses one valid port and one that is too large.
+
+```csharp
+var converter = new StringToShortTypeConverter();
+
+// Success case: valid port number
+var success = converter.TryConvert("8080", conversionHint: null, out var portNumber);
+Console.WriteLine(success);
+Console.WriteLine(portNumber);
+
+// Failure case: port out of valid range
+var overflow = converter.TryConvert("99999", conversionHint: null, out _);
+Console.WriteLine(overflow);
+```
+
+```text
+True
+8080
+False
+```
+
+All seven parse converters work the same way. This excerpt shows the first three. Each one also reports its affinity.
+
+```csharp
+var toByte = new StringToByteTypeConverter();
+_ = toByte.TryConvert("255", conversionHint: null, out var colorChannel);
+Console.WriteLine($"{colorChannel} affinity {toByte.GetAffinityForObjects()}");
+
+var toShort = new StringToShortTypeConverter();
+_ = toShort.TryConvert("8080", conversionHint: null, out var portNumber);
+Console.WriteLine($"{portNumber} affinity {toShort.GetAffinityForObjects()}");
+
+var toInteger = new StringToIntegerTypeConverter();
+_ = toInteger.TryConvert("42", conversionHint: null, out var issueNumber);
+Console.WriteLine($"{issueNumber} affinity {toInteger.GetAffinityForObjects()}");
+```
+
+```text
+255 affinity 2
+8080 affinity 2
+42 affinity 2
+```
+
+The formatting converters follow the same pattern in the other direction. This excerpt turns three numbers into text and prints each affinity, so you can confirm that they all rank the same.
+
+```csharp
+var fromByte = new ByteToStringTypeConverter();
+_ = fromByte.TryConvert(ColorChannelValue, conversionHint: null, out var colorChannel);
+Console.WriteLine($"{colorChannel} affinity {fromByte.GetAffinityForObjects()}");
+
+var fromShort = new ShortToStringTypeConverter();
+_ = fromShort.TryConvert(PortNumber, conversionHint: null, out var portNumber);
+Console.WriteLine($"{portNumber} affinity {fromShort.GetAffinityForObjects()}");
+
+var fromInteger = new IntegerToStringTypeConverter();
+_ = fromInteger.TryConvert(IssueNumber, conversionHint: null, out var issueNumber);
+Console.WriteLine($"{issueNumber} affinity {fromInteger.GetAffinityForObjects()}");
+```
+
+```text
+255 affinity 2
+8080 affinity 2
+42 affinity 2
+```
+
+The [API reference](api.md#numbers) lists every numeric converter.
+
+## Dates, times and durations
+
+Five types have converters: `DateTime`, `DateTimeOffset`, `DateOnly`, `TimeOnly` and `TimeSpan`. The parse converters use the `TryParse` method of their type. The format converters produce the general or short format of the current culture. `TimeSpanToStringTypeConverter` always uses the invariant `c` format.
+
+| Type | Text to value | Value to text |
+| --- | --- | --- |
+| `DateTime` | `StringToDateTimeTypeConverter` | `DateTimeToStringTypeConverter` |
+| `DateTimeOffset` | `StringToDateTimeOffsetTypeConverter` | `DateTimeOffsetToStringTypeConverter` |
+| `DateOnly` | `StringToDateOnlyTypeConverter` | `DateOnlyToStringTypeConverter` |
+| `TimeOnly` | `StringToTimeOnlyTypeConverter` | `TimeOnlyToStringTypeConverter` |
+| `TimeSpan` | `StringToTimeSpanTypeConverter` | `TimeSpanToStringTypeConverter` |
+
+The `DateOnly` and `TimeOnly` converters exist on .NET 8 and later. The .NET Framework targets do not have them.
+
+A user types a due date and time into a task app. This excerpt parses one valid text and one invalid text, so you see how a bad date fails.
+
+```csharp
+var converter = new StringToDateTimeTypeConverter();
+
+// Success case: valid date-time
+var success = converter.TryConvert("2025-12-25T10:30:00", conversionHint: null, out var dueDateTime);
+Console.WriteLine(success);
+Console.WriteLine(dueDateTime);
+
+// Failure case: invalid date format
+var failure = converter.TryConvert("not-a-date", conversionHint: null, out _);
+Console.WriteLine(failure);
+```
+
+```text
+True
+12/25/2025 10:30:00
+False
+```
+
+A time of day fails when it is out of range. `25:00:00` is not a time. The excerpt parses a valid start time and then that bad one.
+
+```csharp
+var converter = new StringToTimeOnlyTypeConverter();
+
+// Success case: valid time
+var success = converter.TryConvert("14:30:00", conversionHint: null, out var startTime);
+Console.WriteLine(success);
+Console.WriteLine(startTime);
+
+// Failure case: invalid time format
+var failure = converter.TryConvert("25:00:00", conversionHint: null, out _);
+Console.WriteLine(failure);
+```
+
+```text
+True
+14:30
+False
+```
+
+A duration formats as `hours:minutes:seconds` whatever the culture. The excerpt formats a project estimate of one and a half hours for display.
+
+```csharp
+var converter = new TimeSpanToStringTypeConverter();
+
+var success = converter.TryConvert(ProjectDuration, conversionHint: null, out var formatted);
+Console.WriteLine(success);
+Console.WriteLine(formatted);
+```
+
+```text
+True
+01:30:00
+```
+
+A `DateTimeOffset` keeps its offset from UTC in the text. This excerpt also shows the four converters that serve one type: text to value, value to text, and the two nullable forms that [Nullable values](#nullable-values) explains.
+
+```csharp
+var toOffset = new StringToDateTimeOffsetTypeConverter();
+_ = toOffset.TryConvert(ModifiedTimeText, conversionHint: null, out var modifiedTime);
+Console.WriteLine($"{modifiedTime} affinity {toOffset.GetAffinityForObjects()}");
+
+var fromOffset = new DateTimeOffsetToStringTypeConverter();
+_ = fromOffset.TryConvert(FileLastModifiedTime, conversionHint: null, out var modifiedTimeText);
+Console.WriteLine($"{modifiedTimeText} affinity {fromOffset.GetAffinityForObjects()}");
+
+var toOptionalOffset = new StringToNullableDateTimeOffsetTypeConverter();
+_ = toOptionalOffset.TryConvert(ModifiedTimeText, conversionHint: null, out var optionalModifiedTime);
+Console.WriteLine($"{optionalModifiedTime} affinity {toOptionalOffset.GetAffinityForObjects()}");
+
+var fromOptionalOffset = new NullableDateTimeOffsetToStringTypeConverter();
+_ = fromOptionalOffset.TryConvert((DateTimeOffset?)FileLastModifiedTime, conversionHint: null, out var optionalModifiedTimeText);
+Console.WriteLine($"{optionalModifiedTimeText} affinity {fromOptionalOffset.GetAffinityForObjects()}");
+```
+
+```text
+09/21/2025 10:30:00 +00:00 affinity 2
+09/21/2025 10:30:00 +00:00 affinity 2
+09/21/2025 10:30:00 +00:00 affinity 2
+09/21/2025 10:30:00 +00:00 affinity 2
+```
+
+The [API reference](api.md#dates-and-times) lists every date and time converter.
+
+## Booleans, GUIDs and URIs
+
+| Type | Text to value | Value to text |
+| --- | --- | --- |
+| `bool` | `StringToBooleanTypeConverter` | `BooleanToStringTypeConverter` |
+| `Guid` | `StringToGuidTypeConverter` | `GuidToStringTypeConverter` |
+| `Uri` | `StringToUriTypeConverter` | `UriToStringTypeConverter` |
+
+`StringToBooleanTypeConverter` accepts `true` and `false` in any letter case. Any other text fails. The excerpt parses `True` and then `maybe`, so you see one success and one failure.
+
+```csharp
+var converter = new StringToBooleanTypeConverter();
+
+// Success case: feature enabled
+var success = converter.TryConvert("True", conversionHint: null, out var isEnabled);
+Console.WriteLine(success);
+Console.WriteLine(isEnabled);
+
+// Failure case: invalid toggle input
+var failure = converter.TryConvert("maybe", conversionHint: null, out _);
+Console.WriteLine(failure);
+```
+
+```text
+True
+True
+False
+```
+
+`StringToGuidTypeConverter` reads a GUID in a standard text form. `GuidToStringTypeConverter` writes the hyphenated `D` format. The excerpt parses a valid GUID and then text that is not one.
+
+```csharp
+var converter = new StringToGuidTypeConverter();
+
+// Success case: valid GUID format
+var success = converter.TryConvert("550e8400-e29b-41d4-a716-446655440000", conversionHint: null, out var correlationId);
+Console.WriteLine(success);
+Console.WriteLine(correlationId);
+
+// Failure case: invalid GUID format
+var failure = converter.TryConvert("not-a-guid", conversionHint: null, out _);
+Console.WriteLine(failure);
+```
+
+```text
+True
+550e8400-e29b-41d4-a716-446655440000
+False
+```
+
+`StringToUriTypeConverter` accepts relative and absolute URIs. It fails for `null` and for text that cannot form a URI. `UriToStringTypeConverter` writes the URI back as text. The excerpt formats a repository URL for display in a link.
+
+```csharp
+var converter = new UriToStringTypeConverter();
+
+var success = converter.TryConvert(ReactiveUiRepositoryUrl, conversionHint: null, out var urlText);
+Console.WriteLine(success);
+Console.WriteLine(urlText);
+```
+
+```text
+True
+https://github.com/reactiveui/ReactiveUI
+```
+
+`bool` and `Guid` also have nullable converters. This excerpt runs all four for a `bool` in one method, so you see the whole set side by side.
+
+```csharp
+var toBoolean = new StringToBooleanTypeConverter();
+_ = toBoolean.TryConvert("True", conversionHint: null, out var isEnabled);
+Console.WriteLine($"{isEnabled} affinity {toBoolean.GetAffinityForObjects()}");
+
+var fromBoolean = new BooleanToStringTypeConverter();
+_ = fromBoolean.TryConvert(true, conversionHint: null, out var enabledText);
+Console.WriteLine($"{enabledText} affinity {fromBoolean.GetAffinityForObjects()}");
+
+var toOptionalBoolean = new StringToNullableBooleanTypeConverter();
+_ = toOptionalBoolean.TryConvert("False", conversionHint: null, out var isOptionalEnabled);
+Console.WriteLine($"{isOptionalEnabled} affinity {toOptionalBoolean.GetAffinityForObjects()}");
+
+var fromOptionalBoolean = new NullableBooleanToStringTypeConverter();
+_ = fromOptionalBoolean.TryConvert((bool?)false, conversionHint: null, out var optionalEnabledText);
+Console.WriteLine($"{optionalEnabledText} affinity {fromOptionalBoolean.GetAffinityForObjects()}");
+```
+
+```text
+True affinity 2
+True affinity 2
+False affinity 2
+False affinity 2
+```
+
+The [API reference](api.md#booleans-guids-and-uris) lists these converters.
+
+## Nullable values
+
+A view model often holds an optional value, such as a due date that is not set yet. A text box shows an empty string for it. Four kinds of converter cover the nullable forms.
+
+- **Text to nullable.** An empty or `null` string succeeds with a `null` result. Text that does not parse still fails.
+- **Nullable to text.** A `null` value succeeds with a `null` string. Any other value formats as its plain form does.
+- **Wrap.** A value becomes its nullable form. This always succeeds.
+- **Unwrap.** A nullable value becomes its plain form. A `null` fails, because a plain type has no way to hold it.
+
+Empty text is a valid answer to "is there a value?", so the text to nullable converters succeed on it. The excerpt parses a number, an empty string and bad text.
+
+```csharp
+var converter = new StringToNullableIntegerTypeConverter();
+
+// Success case: valid issue number
+var success = converter.TryConvert("42", conversionHint: null, out var issueNumber);
+Console.WriteLine(success);
+Console.WriteLine(issueNumber);
+
+// Success case: empty string returns null
+var empty = converter.TryConvert(string.Empty, conversionHint: null, out var noIssue);
+Console.WriteLine(empty);
+Console.WriteLine(noIssue is null);
+
+// Failure case: invalid text
+var failure = converter.TryConvert(InvalidNumberText, conversionHint: null, out _);
+Console.WriteLine(failure);
+```
+
+```text
+True
+42
+True
+True
+False
+```
+
+Pass a nullable value to the nullable to text converters. Cast a plain value to its nullable type first, as `(byte?)` does here. The excerpt formats an optional color channel for display.
+
+```csharp
+var converter = new NullableByteToStringTypeConverter();
+
+var success = converter.TryConvert((byte?)ColorChannelValue, conversionHint: null, out var channelText);
+Console.WriteLine(success);
+Console.WriteLine(channelText);
+```
+
+```text
+True
+255
+```
+
+Wrap converters serve the numeric types. Each reports its type pair and its affinity. The excerpt wraps four whole-number types and prints each result, so you see the target change from the plain type to its `Nullable` form.
+
+```csharp
+var wrapByte = new ByteToNullableByteTypeConverter();
+_ = wrapByte.TryConvertTyped(ColorChannelValue, conversionHint: null, out var colorChannel);
+Console.WriteLine($"{wrapByte.FromType} -> {wrapByte.ToType}: {colorChannel} (affinity {wrapByte.GetAffinityForObjects()})");
+
+var wrapShort = new ShortToNullableShortTypeConverter();
+_ = wrapShort.TryConvertTyped(PortNumber, conversionHint: null, out var portNumber);
+Console.WriteLine($"{wrapShort.FromType} -> {wrapShort.ToType}: {portNumber} (affinity {wrapShort.GetAffinityForObjects()})");
+
+var wrapInteger = new IntegerToNullableIntegerTypeConverter();
+_ = wrapInteger.TryConvertTyped(IssueNumber, conversionHint: null, out var issueNumber);
+Console.WriteLine($"{wrapInteger.FromType} -> {wrapInteger.ToType}: {issueNumber} (affinity {wrapInteger.GetAffinityForObjects()})");
+
+var wrapLong = new LongToNullableLongTypeConverter();
+_ = wrapLong.TryConvertTyped(FileSize, conversionHint: null, out var fileSize);
+Console.WriteLine($"{wrapLong.FromType} -> {wrapLong.ToType}: {fileSize} (affinity {wrapLong.GetAffinityForObjects()})");
+```
+
+```text
+System.Byte -> System.Nullable`1[System.Byte]: 255 (affinity 2)
+System.Int16 -> System.Nullable`1[System.Int16]: 8080 (affinity 2)
+System.Int32 -> System.Nullable`1[System.Int32]: 42 (affinity 2)
+System.Int64 -> System.Nullable`1[System.Int64]: 524288 (affinity 2)
+```
+
+Unwrap converters go the other way. The fractional types show the pattern for `float`, `double` and `decimal`. The excerpt unwraps one value of each type and prints the pair, so you see the `Nullable` source become the plain target.
+
+```csharp
+var unwrapSingle = new NullableSingleToSingleTypeConverter();
+_ = unwrapSingle.TryConvertTyped((float?)Pi, conversionHint: null, out var pi);
+Console.WriteLine($"{unwrapSingle.FromType} -> {unwrapSingle.ToType}: {pi} (affinity {unwrapSingle.GetAffinityForObjects()})");
+
+var unwrapDouble = new NullableDoubleToDoubleTypeConverter();
+_ = unwrapDouble.TryConvertTyped((double?)EulersNumber, conversionHint: null, out var eulersNumber);
+Console.WriteLine($"{unwrapDouble.FromType} -> {unwrapDouble.ToType}: {eulersNumber} (affinity {unwrapDouble.GetAffinityForObjects()})");
+
+var unwrapDecimal = new NullableDecimalToDecimalTypeConverter();
+_ = unwrapDecimal.TryConvertTyped((decimal?)TransferAmount, conversionHint: null, out var transferAmount);
+Console.WriteLine($"{unwrapDecimal.FromType} -> {unwrapDecimal.ToType}: {transferAmount} (affinity {unwrapDecimal.GetAffinityForObjects()})");
+```
+
+```text
+System.Nullable`1[System.Single] -> System.Single: 3.14 (affinity 2)
+System.Nullable`1[System.Double] -> System.Double: 2.71828 (affinity 2)
+System.Nullable`1[System.Decimal] -> System.Decimal: 250.50 (affinity 2)
+```
+
+These two tables name every nullable converter. The numeric types have all four kinds.
+
+| Type | Text to nullable | Nullable to text | Wrap | Unwrap |
+| --- | --- | --- | --- | --- |
+| `byte` | `StringToNullableByteTypeConverter` | `NullableByteToStringTypeConverter` | `ByteToNullableByteTypeConverter` | `NullableByteToByteTypeConverter` |
+| `short` | `StringToNullableShortTypeConverter` | `NullableShortToStringTypeConverter` | `ShortToNullableShortTypeConverter` | `NullableShortToShortTypeConverter` |
+| `int` | `StringToNullableIntegerTypeConverter` | `NullableIntegerToStringTypeConverter` | `IntegerToNullableIntegerTypeConverter` | `NullableIntegerToIntegerTypeConverter` |
+| `long` | `StringToNullableLongTypeConverter` | `NullableLongToStringTypeConverter` | `LongToNullableLongTypeConverter` | `NullableLongToLongTypeConverter` |
+| `float` | `StringToNullableSingleTypeConverter` | `NullableSingleToStringTypeConverter` | `SingleToNullableSingleTypeConverter` | `NullableSingleToSingleTypeConverter` |
+| `double` | `StringToNullableDoubleTypeConverter` | `NullableDoubleToStringTypeConverter` | `DoubleToNullableDoubleTypeConverter` | `NullableDoubleToDoubleTypeConverter` |
+| `decimal` | `StringToNullableDecimalTypeConverter` | `NullableDecimalToStringTypeConverter` | `DecimalToNullableDecimalTypeConverter` | `NullableDecimalToDecimalTypeConverter` |
+
+The other types have the two text converters.
+
+| Type | Text to nullable | Nullable to text |
+| --- | --- | --- |
+| `bool` | `StringToNullableBooleanTypeConverter` | `NullableBooleanToStringTypeConverter` |
+| `Guid` | `StringToNullableGuidTypeConverter` | `NullableGuidToStringTypeConverter` |
+| `DateTime` | `StringToNullableDateTimeTypeConverter` | `NullableDateTimeToStringTypeConverter` |
+| `DateTimeOffset` | `StringToNullableDateTimeOffsetTypeConverter` | `NullableDateTimeOffsetToStringTypeConverter` |
+| `DateOnly` | `StringToNullableDateOnlyTypeConverter` | `NullableDateOnlyToStringTypeConverter` |
+| `TimeOnly` | `StringToNullableTimeOnlyTypeConverter` | `NullableTimeOnlyToStringTypeConverter` |
+| `TimeSpan` | `StringToNullableTimeSpanTypeConverter` | `NullableTimeSpanToStringTypeConverter` |
+
+`Uri` is a reference type and has no nullable converter. The [API reference](api.md#nullable-values) lists them all.
+
+## String and equality
+
+Two converters do not follow the `From`-`To` pattern.
+
+`StringConverter` passes a `string` through unchanged. It serves a binding between two `string` properties. A `null` or a value that is not a `string` fails. The excerpt passes a task title through and prints the two types the converter serves.
+
+```csharp
+var converter = new StringConverter();
+var success = converter.TryConvertTyped("Renew car registration", null, out var result);
+
+Console.WriteLine(success);
+Console.WriteLine(result);
+Console.WriteLine(converter.FromType);
+Console.WriteLine(converter.ToType);
+```
+
+```text
+True
+Renew car registration
+System.String
+System.String
+```
+
+It reports the same affinity as the other built-in converters. The excerpt prints that number.
+
+```csharp
+var converter = new StringConverter();
+
+Console.WriteLine(converter.GetAffinityForObjects());
+```
+
+```text
+2
+```
+
+`EqualityTypeConverter` turns any value into a `bool`. The result says whether the value equals the conversion hint. Use it to show whether a value matches a choice, such as whether an item's priority is `High`. The conversion always succeeds, and two `null` values are equal. `TodoItem` and `TodoPriority` come from the shared example app. The excerpt compares one item's priority with `High` and then with `Low`.
+
+```csharp
+var converter = new EqualityTypeConverter();
+TodoItem item = new() { Title = "Renew car registration", Priority = TodoPriority.High };
+
+var success = converter.TryConvertTyped(item.Priority, TodoPriority.High, out var isHigh);
+
+Console.WriteLine(success);
+Console.WriteLine(isHigh);
+
+success = converter.TryConvertTyped(item.Priority, TodoPriority.Low, out var isLow);
+
+Console.WriteLine(success);
+Console.WriteLine(isLow);
+```
+
+```text
+True
+True
+True
+False
+```
+
+The converter serves the type pair `object` to `bool`. Its affinity is 1, so a converter for that pair with a higher affinity replaces it. The excerpt prints the pair and the affinity.
+
+```csharp
+var converter = new EqualityTypeConverter();
+
+Console.WriteLine($"{converter.FromType} -> {converter.ToType}");
+Console.WriteLine(converter.GetAffinityForObjects());
+```
+
+```text
+System.Object -> System.Boolean
+1
+```
+
+The [API reference](api.md#string-and-equality-converters) lists both.
+
+## Find a converter in the converter service
+
+`BindingConverters.Current` is the converter service that bindings use. It holds three registries. `TypedConverters` matches a converter to an exact source and target type pair. `FallbackConverters` and `SetMethodConverters` serve special cases, and [Custom converters](custom-converters.md) covers them.
+
+The service is empty until you build the app. `BuildApp` replaces it with the service that the builder configured, and `WithCoreServices` puts every built-in converter in that service. [Setup](setup.md) covers the builder. The excerpt reads the service before the build, builds the app, and reads it again, so you see the built-in converters appear.
+
+```csharp
+Console.WriteLine(BindingConverters.Current.TypedConverters.GetAllConverters().Any());
+
+IReactiveUIBindingBuilder builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+_ = builder.WithCoreServices().BuildApp();
+
+var converter = BindingConverters.Current.TypedConverters.TryGetConverter(typeof(int), typeof(string));
+
+Console.WriteLine(BindingConverters.Current.TypedConverters.GetAllConverters().Any());
+Console.WriteLine(converter!.GetType().Name);
+```
+
+```text
+False
+True
+IntegerToStringTypeConverter
+```
+
+`GetAllConverters` returns a copy of every registered converter. `TryGetConverter` takes the source and target types. It returns the converter with the highest affinity for that exact pair. On a tie, the converter registered first wins. It returns `null` when no converter serves the pair, or when every converter for the pair reports an affinity of zero or less. The excerpt looks up four type pairs and checks that the last one has no converter.
+
+```csharp
+var registry = BindingConverters.Current.TypedConverters;
+
+Console.WriteLine(registry.TryGetConverter(typeof(bool), typeof(string))!.GetType().Name);
+Console.WriteLine(registry.TryGetConverter(typeof(string), typeof(Guid))!.GetType().Name);
+Console.WriteLine(registry.TryGetConverter(typeof(DateOnly?), typeof(string))!.GetType().Name);
+Console.WriteLine(registry.TryGetConverter(typeof(TimeSpan), typeof(Guid)) is null);
+```
+
+```text
+BooleanToStringTypeConverter
+StringToGuidTypeConverter
+NullableDateOnlyToStringTypeConverter
+True
+```
+
+There is no built-in converter from `TimeSpan` to `Guid`, so the last line prints `True`. The match is exact. A converter for `int` to `string` does not serve `short` to `string`.
+
+Lookups take no lock. Each registration copies the table, so register converters when the app starts and not on a hot path. Affinity is one scale for converters and for the other mechanisms a binding chooses between, which [Mechanisms](mechanisms.md) covers.
+
+## Show and hide with a Visibility
+
+A view shows or hides a control with a `Visibility` value, and a view model holds a `bool`. The MAUI package ships two converters between them. They live in the `ReactiveUI.Binding.Maui` namespace of the `ReactiveUI.Binding.Maui` package. The WPF package declares a pair with the same names for the WPF `Visibility`, listed under [Platforms](api.md#platforms).
+
+`BooleanToVisibilityTypeConverter` turns `true` into `Visible` and `false` into `Collapsed`. Pass a `BooleanToVisibilityHints` value as the conversion hint to change that. Any other hint means `None`.
+
+| Hint | Effect |
+| --- | --- |
+| `None` | `true` is `Visible`. `false` is `Collapsed`. |
+| `Inverse` | Swaps the mapping. `true` is `Collapsed`. `false` is `Visible`. |
+| `UseHidden` | Uses `Hidden` in place of `Collapsed`. The WinUI build ignores it, because WinUI has no `Hidden`. |
+
+The hints are flags, so `Inverse | UseHidden` applies both. The conversion always succeeds. The excerpt shows a finished to-do item's mark with no hint, with `UseHidden` and with `Inverse`, so you see each mapping.
+
+```csharp
+var converter = new BooleanToVisibilityTypeConverter();
+
+_ = converter.TryConvert(true, conversionHint: null, out var doneMark);
+Console.WriteLine(doneMark);
+
+_ = converter.TryConvert(false, BooleanToVisibilityHints.UseHidden, out var hiddenMark);
+Console.WriteLine(hiddenMark);
+
+_ = converter.TryConvert(true, BooleanToVisibilityHints.Inverse, out var openMark);
+Console.WriteLine(openMark);
+```
+
+```text
+Visible
+Hidden
+Collapsed
+```
+
+`VisibilityToBooleanTypeConverter` goes back. Only `Visible` gives `true`. `Hidden` and `Collapsed` give `false`. The `Inverse` hint flips the result. The excerpt reads a `Visible` value and then a `Collapsed` value with `Inverse`.
+
+```csharp
+var converter = new VisibilityToBooleanTypeConverter();
+
+_ = converter.TryConvert(Microsoft.Maui.Visibility.Visible, conversionHint: null, out var isDone);
+Console.WriteLine(isDone);
+
+_ = converter.TryConvert(Microsoft.Maui.Visibility.Collapsed, BooleanToVisibilityHints.Inverse, out var isOpen);
+Console.WriteLine(isOpen);
+```
+
+```text
+True
+True
+```
+
+`WithMaui()` on the builder registers both converters with the dependency resolver. It does not add them to `TypedConverters`. Create them with `new`, as the example does, and pass the instance where a binding takes a converter. [Custom converters](custom-converters.md) shows how to register a converter in the service.
+
+## Where to go next
+
+- [Custom converters](custom-converters.md) writes a converter, registers it, and replaces a built-in one by giving it a higher affinity.
+- [Bindings](bindings.md) shows the binding calls that use these converters.
+- [Mechanisms](mechanisms.md) covers affinity for observing properties and binding commands.
+- [Setup](setup.md) builds the app and fills the converter service.
+- The [API reference](api.md#converters) lists every converter, the registries and the contracts.
+
+## API reference
+
+Each row is one built-in converter or one member of this page's topic. Every converter is a `sealed` class, and it sits in the `ReactiveUI.Binding` namespace unless its row says otherwise. Each one reports an affinity of 2, except `EqualityTypeConverter`, which reports 1. A converter that does not name a hint ignores it.
+
+| Member | What it does | Type and values | Notes |
+| --- | --- | --- | --- |
+| [`StringConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringConverter.cs) | Passes a `string` through unchanged. | `string` to `string`. | A `null` or a value that is not a `string` fails. Implements `IBindingTypeConverter` only, so call `TryConvertTyped`. |
+| [`EqualityTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/EqualityTypeConverter.cs) | Says whether a value equals the conversion hint. | `object` to `bool`. | Always succeeds, and two `null` values are equal. Affinity 1. Implements `IBindingTypeConverter` only. |
+| [`StringToByteTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToByteTypeConverter.cs) | Parses text into a `byte`. | `string` to `byte`. | `null`, unparseable text and a value above 255 return `false`. Uses the current culture. |
+| [`StringToShortTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToShortTypeConverter.cs) | Parses text into a `short`. | `string` to `short`. | `null`, unparseable text and an out-of-range value return `false`. Uses the current culture. |
+| [`StringToIntegerTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToIntegerTypeConverter.cs) | Parses text into an `int`. | `string` to `int`. | `null`, unparseable text and an out-of-range value return `false`. Uses the current culture. |
+| [`StringToLongTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToLongTypeConverter.cs) | Parses text into a `long`. | `string` to `long`. | `null`, unparseable text and an out-of-range value return `false`. Uses the current culture. |
+| [`StringToSingleTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToSingleTypeConverter.cs) | Parses text into a `float`. | `string` to `float`. | `null` and unparseable text return `false`. Uses the current culture. |
+| [`StringToDoubleTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToDoubleTypeConverter.cs) | Parses text into a `double`. | `string` to `double`. | `null` and unparseable text return `false`. Uses the current culture. |
+| [`StringToDecimalTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToDecimalTypeConverter.cs) | Parses text into a `decimal`. | `string` to `decimal`. | `null` and unparseable text return `false`. Uses the current culture. |
+| [`ByteToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/ByteToStringTypeConverter.cs) | Formats a `byte` as text. | `byte` to `string`. | Always succeeds. Hint: an `int` is the minimum digit count, and a `string` is a format string. A malformed format throws `FormatException`. |
+| [`ShortToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/ShortToStringTypeConverter.cs) | Formats a `short` as text. | `short` to `string`. | Always succeeds. Hint: an `int` is the minimum digit count, and a `string` is a format string. A malformed format throws `FormatException`. |
+| [`IntegerToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/IntegerToStringTypeConverter.cs) | Formats an `int` as text. | `int` to `string`. | Always succeeds. Hint: an `int` is the minimum digit count, and a `string` is a format string. A malformed format throws `FormatException`. |
+| [`LongToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/LongToStringTypeConverter.cs) | Formats a `long` as text. | `long` to `string`. | Always succeeds. Hint: an `int` is the minimum digit count, and a `string` is a format string. A malformed format throws `FormatException`. |
+| [`SingleToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/SingleToStringTypeConverter.cs) | Formats a `float` as text. | `float` to `string`. | Always succeeds. Hint: an `int` is the number of decimal places, and a `string` is a format string. A malformed format throws `FormatException`. |
+| [`DoubleToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/DoubleToStringTypeConverter.cs) | Formats a `double` as text. | `double` to `string`. | Always succeeds. Hint: an `int` is the number of decimal places, and a `string` is a format string. A malformed format throws `FormatException`. |
+| [`DecimalToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/DecimalToStringTypeConverter.cs) | Formats a `decimal` as text. | `decimal` to `string`. | Always succeeds. Hint: an `int` is the number of decimal places, and a `string` is a format string. A malformed format throws `FormatException`. |
+| [`StringToDateTimeTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToDateTimeTypeConverter.cs) | Parses text into a `DateTime`. | `string` to `DateTime`. | `null` and unparseable text return `false`. Uses the current culture. |
+| [`DateTimeToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/DateTimeToStringTypeConverter.cs) | Formats a `DateTime` as text. | `DateTime` to `string`. | Always succeeds. Uses the general date and time format of the current culture. |
+| [`StringToDateTimeOffsetTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToDateTimeOffsetTypeConverter.cs) | Parses text into a `DateTimeOffset`. | `string` to `DateTimeOffset`. | `null` and unparseable text return `false`. Uses the current culture. |
+| [`DateTimeOffsetToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/DateTimeOffsetToStringTypeConverter.cs) | Formats a `DateTimeOffset` as text. | `DateTimeOffset` to `string`. | Always succeeds. Uses the general format of the current culture and includes the offset. |
+| [`StringToDateOnlyTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToDateOnlyTypeConverter.cs) | Parses text into a `DateOnly`. | `string` to `DateOnly`; .NET 8 and later. | `null` and unparseable text return `false`. Uses the current culture. |
+| [`DateOnlyToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/DateOnlyToStringTypeConverter.cs) | Formats a `DateOnly` as text. | `DateOnly` to `string`; .NET 8 and later. | Always succeeds. Uses the short date format of the current culture. |
+| [`StringToTimeOnlyTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToTimeOnlyTypeConverter.cs) | Parses text into a `TimeOnly`. | `string` to `TimeOnly`; .NET 8 and later. | `null` and unparseable text return `false`. Uses the current culture. |
+| [`TimeOnlyToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/TimeOnlyToStringTypeConverter.cs) | Formats a `TimeOnly` as text. | `TimeOnly` to `string`; .NET 8 and later. | Always succeeds. Uses the short time format of the current culture. |
+| [`StringToTimeSpanTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToTimeSpanTypeConverter.cs) | Parses text into a `TimeSpan`. | `string` to `TimeSpan`. | `null` and unparseable text return `false`. Uses the current culture. |
+| [`TimeSpanToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/TimeSpanToStringTypeConverter.cs) | Formats a `TimeSpan` as text. | `TimeSpan` to `string`. | Always succeeds. Uses the invariant `c` format. |
+| [`StringToBooleanTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToBooleanTypeConverter.cs) | Parses text into a `bool`. | `string` to `bool`. | Accepts `true` and `false` in any letter case. `null` and other text return `false`. |
+| [`BooleanToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/BooleanToStringTypeConverter.cs) | Formats a `bool` as text. | `bool` to `string`. | Always succeeds. Writes `True` or `False`. |
+| [`StringToGuidTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToGuidTypeConverter.cs) | Parses text into a `Guid`. | `string` to `Guid`. | `null` and unparseable text return `false`. |
+| [`GuidToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/GuidToStringTypeConverter.cs) | Formats a `Guid` as text. | `Guid` to `string`. | Always succeeds. Writes the hyphenated `D` format. |
+| [`StringToUriTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToUriTypeConverter.cs) | Creates a `Uri` from text. | `string` to `Uri`. | Accepts relative and absolute URIs. `null` and text that cannot form a URI return `false`. |
+| [`UriToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/UriToStringTypeConverter.cs) | Writes a `Uri` as text with `ToString`. | `Uri` to `string`. | A `null` value returns `false`. |
+| [`StringToNullableByteTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableByteTypeConverter.cs) | Parses optional text into a `byte?`. | `string` to `byte?`. | `null` or empty text gives a `null` result. Unparseable or out-of-range text returns `false`. Uses the current culture. |
+| [`StringToNullableShortTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableShortTypeConverter.cs) | Parses optional text into a `short?`. | `string` to `short?`. | `null` or empty text gives a `null` result. Unparseable or out-of-range text returns `false`. Uses the current culture. |
+| [`StringToNullableIntegerTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableIntegerTypeConverter.cs) | Parses optional text into an `int?`. | `string` to `int?`. | `null` or empty text gives a `null` result. Unparseable or out-of-range text returns `false`. Uses the current culture. |
+| [`StringToNullableLongTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableLongTypeConverter.cs) | Parses optional text into a `long?`. | `string` to `long?`. | `null` or empty text gives a `null` result. Unparseable or out-of-range text returns `false`. Uses the current culture. |
+| [`StringToNullableSingleTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableSingleTypeConverter.cs) | Parses optional text into a `float?`. | `string` to `float?`. | `null` or empty text gives a `null` result. Unparseable text returns `false`. Uses the current culture. |
+| [`StringToNullableDoubleTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableDoubleTypeConverter.cs) | Parses optional text into a `double?`. | `string` to `double?`. | `null` or empty text gives a `null` result. Unparseable text returns `false`. Uses the current culture. |
+| [`StringToNullableDecimalTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableDecimalTypeConverter.cs) | Parses optional text into a `decimal?`. | `string` to `decimal?`. | `null` or empty text gives a `null` result. Unparseable text returns `false`. Uses the current culture. |
+| [`NullableByteToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableByteToStringTypeConverter.cs) | Formats a `byte?` as text. | `byte?` to `string`. | Always succeeds. A `null` value gives a `null` string. Hint: an `int` is the minimum digit count, and a `string` is a format string. |
+| [`NullableShortToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableShortToStringTypeConverter.cs) | Formats a `short?` as text. | `short?` to `string`. | Always succeeds. A `null` value gives a `null` string. Hint: an `int` is the minimum digit count, and a `string` is a format string. |
+| [`NullableIntegerToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableIntegerToStringTypeConverter.cs) | Formats an `int?` as text. | `int?` to `string`. | Always succeeds. A `null` value gives a `null` string. Hint: an `int` is the minimum digit count, and a `string` is a format string. |
+| [`NullableLongToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableLongToStringTypeConverter.cs) | Formats a `long?` as text. | `long?` to `string`. | Always succeeds. A `null` value gives a `null` string. Hint: an `int` is the minimum digit count, and a `string` is a format string. |
+| [`NullableSingleToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableSingleToStringTypeConverter.cs) | Formats a `float?` as text. | `float?` to `string`. | Always succeeds. A `null` value gives a `null` string. Hint: an `int` is the number of decimal places, and a `string` is a format string. |
+| [`NullableDoubleToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableDoubleToStringTypeConverter.cs) | Formats a `double?` as text. | `double?` to `string`. | Always succeeds. A `null` value gives a `null` string. Hint: an `int` is the number of decimal places, and a `string` is a format string. |
+| [`NullableDecimalToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableDecimalToStringTypeConverter.cs) | Formats a `decimal?` as text. | `decimal?` to `string`. | Always succeeds. A `null` value gives a `null` string. Hint: an `int` is the number of decimal places, and a `string` is a format string. |
+| [`ByteToNullableByteTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/ByteToNullableByteTypeConverter.cs) | Wraps a `byte` in its nullable form. | `byte` to `byte?`. | Always succeeds. |
+| [`ShortToNullableShortTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/ShortToNullableShortTypeConverter.cs) | Wraps a `short` in its nullable form. | `short` to `short?`. | Always succeeds. |
+| [`IntegerToNullableIntegerTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/IntegerToNullableIntegerTypeConverter.cs) | Wraps an `int` in its nullable form. | `int` to `int?`. | Always succeeds. |
+| [`LongToNullableLongTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/LongToNullableLongTypeConverter.cs) | Wraps a `long` in its nullable form. | `long` to `long?`. | Always succeeds. |
+| [`SingleToNullableSingleTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/SingleToNullableSingleTypeConverter.cs) | Wraps a `float` in its nullable form. | `float` to `float?`. | Always succeeds. |
+| [`DoubleToNullableDoubleTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/DoubleToNullableDoubleTypeConverter.cs) | Wraps a `double` in its nullable form. | `double` to `double?`. | Always succeeds. |
+| [`DecimalToNullableDecimalTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/DecimalToNullableDecimalTypeConverter.cs) | Wraps a `decimal` in its nullable form. | `decimal` to `decimal?`. | Always succeeds. |
+| [`NullableByteToByteTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableByteToByteTypeConverter.cs) | Unwraps a `byte?`. | `byte?` to `byte`. | A `null` value returns `false`. |
+| [`NullableShortToShortTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableShortToShortTypeConverter.cs) | Unwraps a `short?`. | `short?` to `short`. | A `null` value returns `false`. |
+| [`NullableIntegerToIntegerTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableIntegerToIntegerTypeConverter.cs) | Unwraps an `int?`. | `int?` to `int`. | A `null` value returns `false`. |
+| [`NullableLongToLongTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableLongToLongTypeConverter.cs) | Unwraps a `long?`. | `long?` to `long`. | A `null` value returns `false`. |
+| [`NullableSingleToSingleTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableSingleToSingleTypeConverter.cs) | Unwraps a `float?`. | `float?` to `float`. | A `null` value returns `false`. |
+| [`NullableDoubleToDoubleTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableDoubleToDoubleTypeConverter.cs) | Unwraps a `double?`. | `double?` to `double`. | A `null` value returns `false`. |
+| [`NullableDecimalToDecimalTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableDecimalToDecimalTypeConverter.cs) | Unwraps a `decimal?`. | `decimal?` to `decimal`. | A `null` value returns `false`. |
+| [`StringToNullableBooleanTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableBooleanTypeConverter.cs) | Parses optional text into a `bool?`. | `string` to `bool?`. | `null` or empty text gives a `null` result. Text other than `true` or `false` returns `false`. |
+| [`NullableBooleanToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableBooleanToStringTypeConverter.cs) | Formats a `bool?` as text. | `bool?` to `string`. | Always succeeds. Writes `True` or `False`, and a `null` value gives a `null` string. |
+| [`StringToNullableGuidTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableGuidTypeConverter.cs) | Parses optional text into a `Guid?`. | `string` to `Guid?`. | `null` or empty text gives a `null` result. Unparseable text returns `false`. |
+| [`NullableGuidToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableGuidToStringTypeConverter.cs) | Formats a `Guid?` as text. | `Guid?` to `string`. | Always succeeds. Writes the hyphenated `D` format, and a `null` value gives a `null` string. |
+| [`StringToNullableDateTimeTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableDateTimeTypeConverter.cs) | Parses optional text into a `DateTime?`. | `string` to `DateTime?`. | `null` or empty text gives a `null` result. Unparseable text returns `false`. Uses the current culture. |
+| [`NullableDateTimeToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableDateTimeToStringTypeConverter.cs) | Formats a `DateTime?` as text. | `DateTime?` to `string`. | Always succeeds. Uses the general format of the current culture, and a `null` value gives a `null` string. |
+| [`StringToNullableDateTimeOffsetTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableDateTimeOffsetTypeConverter.cs) | Parses optional text into a `DateTimeOffset?`. | `string` to `DateTimeOffset?`. | `null` or empty text gives a `null` result. Unparseable text returns `false`. Uses the current culture. |
+| [`NullableDateTimeOffsetToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableDateTimeOffsetToStringTypeConverter.cs) | Formats a `DateTimeOffset?` as text. | `DateTimeOffset?` to `string`. | Always succeeds. Includes the offset, and a `null` value gives a `null` string. |
+| [`StringToNullableDateOnlyTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableDateOnlyTypeConverter.cs) | Parses optional text into a `DateOnly?`. | `string` to `DateOnly?`; .NET 8 and later. | `null` or empty text gives a `null` result. Unparseable text returns `false`. Uses the current culture. |
+| [`NullableDateOnlyToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableDateOnlyToStringTypeConverter.cs) | Formats a `DateOnly?` as text. | `DateOnly?` to `string`; .NET 8 and later. | Always succeeds. Uses the short date format of the current culture, and a `null` value gives a `null` string. |
+| [`StringToNullableTimeOnlyTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableTimeOnlyTypeConverter.cs) | Parses optional text into a `TimeOnly?`. | `string` to `TimeOnly?`; .NET 8 and later. | `null` or empty text gives a `null` result. Unparseable text returns `false`. Uses the current culture. |
+| [`NullableTimeOnlyToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableTimeOnlyToStringTypeConverter.cs) | Formats a `TimeOnly?` as text. | `TimeOnly?` to `string`; .NET 8 and later. | Always succeeds. Uses the short time format of the current culture, and a `null` value gives a `null` string. |
+| [`StringToNullableTimeSpanTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/StringToNullableTimeSpanTypeConverter.cs) | Parses optional text into a `TimeSpan?`. | `string` to `TimeSpan?`. | `null` or empty text gives a `null` result. Unparseable text returns `false`. Uses the current culture. |
+| [`NullableTimeSpanToStringTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converter/NullableTimeSpanToStringTypeConverter.cs) | Formats a `TimeSpan?` as text. | `TimeSpan?` to `string`. | Always succeeds. Uses the invariant `c` format, and a `null` value gives a `null` string. |
+| [`BooleanToVisibilityTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Maui.Shared/BooleanToVisibilityTypeConverter.cs) | Turns a `bool` into a `Visibility`. | `bool` to MAUI `Visibility`. Namespace `ReactiveUI.Binding.Maui`. | Always succeeds. `true` is `Visible`, and `false` is `Collapsed`. Hint: a `BooleanToVisibilityHints` value. Any other hint means `None`. |
+| [`VisibilityToBooleanTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Maui.Shared/VisibilityToBooleanTypeConverter.cs) | Turns a `Visibility` into a `bool`. | MAUI `Visibility` to `bool`. Namespace `ReactiveUI.Binding.Maui`. | Always succeeds. Only `Visible` gives `true`. Hint: `Inverse` flips the result. Any other hint means `None`. |
+| [`BooleanToVisibilityHints`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Maui.Shared/BooleanToVisibilityHints.cs) | Chooses how a `bool` maps to a `Visibility`. | Flags enum: `None = 0`, `Inverse = 2`, `UseHidden = 4`. Namespace `ReactiveUI.Binding.Maui`. | Pass a value as the conversion hint. `UseHidden` is ignored on WinUI. |
+| [`BindingConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/BindingConverters.cs) | Holds the converter service that bindings convert through. | Static class. `Current` is a `ConverterService`. | `Current` starts empty. `BuildApp` replaces it with the configured service, which holds the built-in converters. |
+| [`ConverterService`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ConverterService.cs) | Owns the typed, fallback and set-method registries. | Properties `TypedConverters`, `FallbackConverters` and `SetMethodConverters`. Method `ResolveConverter(Type, Type)`. | `ResolveConverter` returns the typed converter for the pair first, then a fallback converter, and `null` when neither exists. A new service holds no converters. |
+| [`BindingTypeConverterRegistry`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/BindingTypeConverterRegistry.cs) | Holds typed converters grouped by exact type pair. | Methods `Register`, `TryGetConverter(Type, Type)` and `GetAllConverters()`. | `TryGetConverter` returns the highest positive affinity, the earliest registered converter on a tie, and `null` when none applies. Lookups take no lock. |
+| [`DefaultConverterRegistration`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/DefaultConverterRegistration.cs) | Registers every built-in converter with a `ConverterService`. | Static method `RegisterDefaults(ConverterService)`. | Registers no fallback or set-method converters. Calling it twice adds every converter twice. Registers the `DateOnly` and `TimeOnly` converters on .NET 8 and later only. |
diff --git a/docs/documentation/binding/custom-converters.md b/docs/documentation/binding/custom-converters.md
new file mode 100644
index 00000000..158da890
--- /dev/null
+++ b/docs/documentation/binding/custom-converters.md
@@ -0,0 +1,1034 @@
+---
+Order: 5
+---
+# Custom converters
+
+[Run the complete page example](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/custom-converters/custom-converters.csproj).
+
+A binding joins two properties. Sometimes the two properties have different types, and the library has no built-in converter for that pair. A to-do app might show a `TodoPriority` as a colour name in a `Label`. A form might keep the tags of a task in an `IReadOnlyList<string>` and show them in an `Entry` as one line of text. A converter teaches the binding how to move a value between the two types.
+
+The [converters page](converters.md) covers the built-in converters and the idea of a converter. This page covers the converters you write yourself. It shows how to write one and how to hand it to a binding. It shows how to register one so every binding finds it. It ends with moving converters over from a ReactiveUI app. Start with the walkthrough below. If you stop after it, you can write and use a converter.
+
+The outputs assume the invariant culture, which the example project sets at start-up. Several converters format and parse with the current culture.
+
+## Write a converter and use it
+
+**1. Derive from `BindingTypeConverter`.** `BindingTypeConverter<TFrom, TTo>` is the base class for a converter between one pair of types. It supplies `FromType`, `ToType` and the boxed `TryConvertTyped` method. You write two members: `GetAffinityForObjects`, which scores the converter, and `TryConvert`, which converts one value. The converter below turns a `TodoPriority` into a colour name, the kind of text a `Label` can show.
+
+```csharp
+public sealed class TodoPriorityToColorConverter : BindingTypeConverter<TodoPriority, string>
+{
+    private const int ConvertorAffinity = 10;
+
+    public override int GetAffinityForObjects() => ConvertorAffinity;
+
+    public override bool TryConvert(TodoPriority from, object? conversionHint, [MaybeNullWhen(true)] out string? result)
+    {
+        result = from switch
+        {
+            TodoPriority.Low => "Gray",
+            TodoPriority.Normal => "Orange",
+            TodoPriority.High => "Red",
+            _ => null,
+        };
+
+        return result is not null;
+    }
+}
+```
+
+`TryConvert` returns `true` and sets `result` when the conversion works. It returns `false` when it cannot convert the value. The switch gives `null` for a `TodoPriority` value it does not list, so the converter reports a failure instead of inventing a colour.
+
+**2. Score it.** Affinity is a number that ranks the converters for one pair of types. A positive number means the converter applies. Zero or less excludes it. The highest number wins, and the converter registered first wins a tie. The built-in converters score 2 and the equality converter scores 1, so a converter that scores 10 outranks them all.
+
+**3. Call it on its own.** A converter is an ordinary object. You can call `TryConvert` on it without a binding, which is the easiest way to test one. The loop below converts every priority and prints whether each conversion worked.
+
+```csharp
+var converter = new TodoPriorityToColorConverter();
+
+foreach (var priority in Enum.GetValues<TodoPriority>())
+{
+    var success = converter.TryConvert(priority, null, out var colorName);
+    Console.WriteLine($"{priority}: {success} {colorName}");
+}
+```
+
+```text
+Low: True Gray
+Normal: True Orange
+High: True Red
+```
+
+**4. Pass it to a binding.** `BindOneWay` takes the converter as its last argument. The binding writes the colour name to the label at once and again each time the priority changes. The lambdas name the source property and the target property, as they do on the [bindings page](bindings.md).
+
+```csharp
+TodoItem item = new() { Title = CarRegistrationTitle, Priority = TodoPriority.High };
+Label badge = new();
+
+using var binding = item.BindOneWay(badge, x => x.Priority, x => x.Text, new TodoPriorityToColorConverter());
+Console.WriteLine(badge.Text);
+
+item.Priority = TodoPriority.Low;
+Console.WriteLine(badge.Text);
+```
+
+```text
+Red
+Gray
+```
+
+`using var` disposes the binding at the end of the method, which stops the label from following the item.
+
+**5. Register it once.** Passing a converter to every binding gets repetitive. Register the converter with the shared converter service instead, and every binding between the two types finds it. `BindingConverters.Current` is that service. Its `TypedConverters` registry holds converters for one exact pair of types. `TryGetConverter` returns the best one for a pair. The excerpt registers the converter, fetches it back by its two types and converts two priorities. That shows the service can find the converter without a binding.
+
+```csharp
+BindingConverters.Current.TypedConverters.Register(new TodoPriorityToColorConverter());
+
+var converter = BindingConverters.Current.TypedConverters.TryGetConverter(typeof(TodoPriority), typeof(string));
+
+var success = converter!.TryConvertTyped(TodoPriority.High, null, out var highColor);
+Console.WriteLine(success);
+Console.WriteLine(highColor);
+
+success = converter.TryConvertTyped(TodoPriority.Low, null, out var lowColor);
+Console.WriteLine(success);
+Console.WriteLine(lowColor);
+```
+
+```text
+True
+Red
+True
+Gray
+```
+
+`TryConvertTyped` is the boxed form of `TryConvert`. It takes and returns `object`, so it works on a converter you fetched from a registry without knowing its types. The [registration section](#register-converters) below covers the registries in full.
+
+## Choose how to implement the interface
+
+Two shapes exist for a converter, and both register the same way.
+
+The base class is the shorter one. `BindingTypeConverter<TFrom, TTo>` also implements `IBindingTypeConverter<TFrom, TTo>`, which adds a typed `TryConvert`. A generated binding calls the typed method when it can, so a value type is not boxed on the way through. Prefer the base class.
+
+The interface is the longer one. `IBindingTypeConverter` has four members: `FromType`, `ToType`, `GetAffinityForObjects` and `TryConvertTyped`. Implement it directly when the converter must derive from another class. You write the type checks yourself. The class below does the same priority-to-colour job as the first converter, but it implements the interface directly.
+
+```csharp
+public sealed class PriorityColourConverter : IBindingTypeConverter
+{
+    private const int ColourAffinity = 20;
+
+    public Type FromType => typeof(TodoPriority);
+
+    public Type ToType => typeof(string);
+
+    public int GetAffinityForObjects() => ColourAffinity;
+
+    public bool TryConvertTyped(object? from, object? conversionHint, [NotNullWhen(true)] out object? result)
+    {
+        result = from switch
+        {
+            TodoPriority.Low => "Green",
+            TodoPriority.Normal => "Amber",
+            TodoPriority.High => "Crimson",
+            _ => null,
+        };
+
+        return result is not null;
+    }
+}
+```
+
+The `from switch` matches only a `TodoPriority`. Any other value falls to `null`, and the method returns `false`. The next excerpt calls the converter directly. It prints the two types, the score and the result for a `TodoPriority`, then tries a `string` to show the failure.
+
+```csharp
+var converter = new PriorityColourConverter();
+
+Console.WriteLine($"{converter.FromType.Name} -> {converter.ToType.Name}");
+Console.WriteLine(converter.GetAffinityForObjects());
+Console.WriteLine(converter.TryConvertTyped(TodoPriority.High, null, out var colour));
+Console.WriteLine(colour);
+Console.WriteLine(converter.TryConvertTyped("High", null, out var notAPriority));
+Console.WriteLine(notAPriority is null);
+```
+
+```text
+TodoPriority -> String
+20
+True
+Crimson
+False
+True
+```
+
+A binding uses this converter as it uses the base-class one. This binding shows a priority as a colour name through it.
+
+```csharp
+TodoItem item = new() { Title = CarRegistrationTitle, Priority = TodoPriority.High };
+Label badge = new();
+
+using var binding = item.BindOneWay(badge, x => x.Priority, x => x.Text, new PriorityColourConverter());
+Console.WriteLine(badge.Text);
+
+item.Priority = TodoPriority.Low;
+Console.WriteLine(badge.Text);
+```
+
+```text
+Crimson
+Green
+```
+
+### Call a converter through its base class or its interfaces
+
+A converter can be held as its base class, as the untyped interface or as the typed interface. `CurrencyTextConverter` derives from `BindingTypeConverter<decimal, string>`. The first excerpt holds it as the base class and calls the typed `TryConvert`.
+
+```csharp
+BindingTypeConverter<decimal, string> converter = new CurrencyTextConverter(DollarSymbol);
+
+Console.WriteLine($"{converter.FromType.Name} -> {converter.ToType.Name}");
+Console.WriteLine(converter.GetAffinityForObjects());
+Console.WriteLine(converter.TryConvert(TransferAmount, conversionHint: null, out var amountText));
+Console.WriteLine(amountText);
+```
+
+```text
+Decimal -> String
+10
+True
+$250.50
+```
+
+A registry returns the untyped `IBindingTypeConverter`. The second excerpt gets the converter from a registry and casts it to `IBindingTypeConverter<TFrom, TTo>`, which has the typed `TryConvert`.
+
+```csharp
+ConverterService service = new();
+service.TypedConverters.Register(new CurrencyTextConverter(DollarSymbol));
+
+var untyped = service.TypedConverters.TryGetConverter(typeof(decimal), typeof(string))!;
+var typed = (IBindingTypeConverter<decimal, string>)untyped;
+
+Console.WriteLine($"{untyped.FromType.Name} -> {untyped.ToType.Name}");
+Console.WriteLine(typed.TryConvert(TransferAmount, conversionHint: null, out var amountText));
+Console.WriteLine(amountText);
+```
+
+```text
+Decimal -> String
+True
+$250.50
+```
+
+A converter takes constructor arguments like any class. Here the currency symbol comes from the constructor.
+
+### Use the conversion hint
+
+Every conversion method takes a `conversionHint`. The hint is an extra value the caller passes to the converter, such as a format string. A converter may ignore it. `PriorityMatchesHintConverter` reads it: it returns `true` when the priority equals the priority passed as the hint. The next section shows a binding that passes the hint. The class below compares the priority with the hint, so one converter can answer a different question for each binding.
+
+```csharp
+public sealed class PriorityMatchesHintConverter : BindingTypeConverter<TodoPriority, bool>
+{
+    private const int MatchAffinity = 10;
+
+    public override int GetAffinityForObjects() => MatchAffinity;
+
+    public override bool TryConvert(TodoPriority from, object? conversionHint, out bool result)
+    {
+        result = conversionHint is TodoPriority expected && from == expected;
+        return true;
+    }
+}
+```
+
+## Pass a converter to a binding
+
+A binding that gets a converter object uses it for that binding only. It ignores the registries. Five binding methods take a converter: `BindOneWay`, `BindTwoWay`, `OneWayBind`, `Bind` and `BindTo`. `BindOneWay` and `BindTwoWay` join two properties from the model side. `OneWayBind` and `Bind` join a view to its view model. `BindTo` writes the values of an observable to a property. The [bindings page](bindings.md) explains the differences.
+
+When a converter returns `false`, the binding writes nothing for that value. The target keeps its last value.
+
+### Pass a hint with the converter
+
+`BindOneWay` takes an optional conversion hint after the converter. This binding ticks a check box while the priority equals the hint. Changing the priority to `Low` unticks the box.
+
+```csharp
+TodoItem item = new() { Title = CarRegistrationTitle, Priority = TodoPriority.High };
+CheckBox highPriorityBox = new();
+
+using var binding = item.BindOneWay(highPriorityBox, x => x.Priority, x => x.IsChecked, new PriorityMatchesHintConverter(), TodoPriority.High);
+Console.WriteLine(highPriorityBox.IsChecked);
+
+item.Priority = TodoPriority.Low;
+Console.WriteLine(highPriorityBox.IsChecked);
+```
+
+```text
+True
+False
+```
+
+`BindTo` takes the hint before the converter. It writes the values of an observable, here the changes of the priority, to the check box.
+
+```csharp
+TodoItem item = new() { Title = CarRegistrationTitle, Priority = TodoPriority.High };
+CheckBox highPriorityBox = new();
+
+using (item.WhenChanged(x => x.Priority).BindTo(highPriorityBox, x => x.IsChecked, TodoPriority.High, new PriorityMatchesHintConverter()))
+{
+    Console.WriteLine(highPriorityBox.IsChecked);
+
+    item.Priority = TodoPriority.Low;
+    Console.WriteLine(highPriorityBox.IsChecked);
+}
+```
+
+```text
+True
+False
+```
+
+`WhenChanged` is an observable that emits each value of a property. See [observing](observing.md).
+
+### Pass one converter for each direction
+
+A two-way binding moves values both ways, so it needs two conversions. `BindTwoWay` and `Bind` take two converters. The first converts from the source to the target, and the second converts back. The built-in `NullableDateOnlyToStringTypeConverter` and `StringToNullableDateOnlyTypeConverter` do the work here. You can pass your own the same way.
+
+```csharp
+var store = InMemoryTodoStore.CreateSeeded();
+var item = (await store.GetAsync(DentistTaskId))!;
+Entry dueDateBox = new();
+
+using var binding = item.BindTwoWay(
+    dueDateBox,
+    x => x.DueDate,
+    x => x.Text,
+    new NullableDateOnlyToStringTypeConverter(),
+    new StringToNullableDateOnlyTypeConverter());
+Console.WriteLine(dueDateBox.Text);
+
+dueDateBox.Text = TypedDueDate;
+Console.WriteLine(item.DueDate);
+```
+
+```text
+04/02/2026
+05/01/2026
+```
+
+The same shape works for a converter pair of your own. This binding keeps the tags of a task and a text box in step. `TagListToTextConverter` joins the tags with a comma. `TextToTagListConverter` splits the text at the commas, trims each tag and drops blank ones.
+
+```csharp
+TodoItem item = new() { Title = CarRegistrationTitle, Tags = ["car", "admin"] };
+Entry tagsBox = new();
+
+using var binding = item.BindTwoWay(tagsBox, x => x.Tags, x => x.Text, new TagListToTextConverter(), new TextToTagListConverter());
+Console.WriteLine(tagsBox.Text);
+
+tagsBox.Text = TypedTags;
+Console.WriteLine(string.Join("|", item.Tags));
+```
+
+```text
+car, admin
+car|admin|urgent
+```
+
+Each half is also a plain converter. This excerpt calls both halves without a binding, so you can test each direction on its own.
+
+```csharp
+var toText = new TagListToTextConverter();
+var toTags = new TextToTagListConverter();
+TodoItem item = new() { Title = CarRegistrationTitle, Tags = ["car", "admin"] };
+
+Console.WriteLine(toText.TryConvert(item.Tags, null, out var text));
+Console.WriteLine(text);
+Console.WriteLine(toTags.TryConvert(TypedTags, null, out var tags));
+Console.WriteLine(string.Join("|", tags!));
+```
+
+```text
+True
+car, admin
+True
+car|admin|urgent
+```
+
+### Bind a view to a view model with converters
+
+The view-first methods `OneWayBind` and `Bind` take the converters as well. The lambda for the view model reads from the view model. The lambda for the view reads from the view. `OneWayBind` shows the total balance as text through the built-in `DecimalToStringTypeConverter`.
+
+```csharp
+AccountsView view = new();
+AccountsViewModel viewModel = new(new InMemoryBankingBackend());
+view.ViewModel = viewModel;
+
+using var binding = view.OneWayBind(viewModel, x => x.TotalBalance, v => v.TotalBalanceLabel.Text, new DecimalToStringTypeConverter());
+await viewModel.LoadAccountsAsync();
+
+Console.WriteLine(view.TotalBalanceLabel.Text);
+```
+
+```text
+17680.75
+```
+
+`Bind` keeps the transfer amount and its text box in step. It takes a converter for each direction. The excerpt sets the amount in the view model and prints the text box, then types text in the box and prints the amount in the view model.
+
+```csharp
+TransferView view = new();
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+view.ViewModel = viewModel;
+
+using var binding = view.Bind(
+    viewModel,
+    x => x.Draft.Amount,
+    v => v.AmountTextBox.Text,
+    new DecimalToStringTypeConverter(),
+    new StringToDecimalTypeConverter());
+
+viewModel.Draft.Amount = TransferAmount;
+Console.WriteLine(view.AmountTextBox.Text);
+
+view.AmountTextBox.Text = TypedAmount;
+Console.WriteLine(viewModel.Draft.Amount);
+```
+
+```text
+250.50
+99.95
+```
+
+The converter overloads of `BindOneWay`, `BindTwoWay`, `OneWayBind` and `Bind` keep the parameter names of the library's own methods. A call that names an argument, such as `conversionHint:`, resolves to them. The scheduler parameter is optional and comes last. When you leave it out, or pass `null`, the binding writes on the thread that owns the target. See [threading](threading.md).
+
+### Build a list of views from a list of view models
+
+A converter can produce more than a `string`. `AccountsToViewsConverter` converts a list of accounts into a list of views, one for each account. It asks a view locator for each view. A view locator finds the view class that belongs to a view model. See [views](views.md).
+
+The converter takes the locator through its constructor. It derives from `BindingTypeConverter<IReadOnlyList<Account>, IEnumerable>` and scores 10. A `null` list fails the conversion, so the binding writes nothing. A view model with no matching view is left out of the result. The binding below maps `Account` to `AccountSummaryView` in a locator, then shows every account as a row.
+
+```csharp
+DefaultViewLocator locator = new();
+locator.Map<Account, AccountSummaryView>();
+AccountsView view = new();
+AccountsViewModel viewModel = new(new InMemoryBankingBackend());
+view.ViewModel = viewModel;
+
+using var binding = view.OneWayBind(viewModel, x => x.Accounts, v => v.AccountList.ItemsSource, new AccountsToViewsConverter(locator));
+await viewModel.LoadAccountsAsync();
+
+foreach (var row in view.AccountList.ItemsSource.OfType<AccountSummaryView>())
+{
+    Console.WriteLine(row.ViewModel!.Name);
+}
+```
+
+```text
+Everyday Account
+Savings Account
+```
+
+## Register converters
+
+A registered converter serves every binding, so you do not pass it each time. The converter service `ConverterService` owns three registries. Each registry has its own job.
+
+| Property | Interface it holds | What it holds |
+| --- | --- | --- |
+| `TypedConverters` | `IBindingTypeConverter` | Converters for one exact source type and target type, such as `int` to `string`. |
+| `FallbackConverters` | `IBindingFallbackConverter` | Converters the library asks only when no typed converter matches. |
+| `SetMethodConverters` | `ISetMethodBindingConverter` | Converters that change how a binding writes to its target. |
+
+`BindingConverters.Current` is the service that bindings use. It starts empty. The builder's `WithCoreServices` registers the built-in converters in the builder's own service, and `BuildApp` replaces `Current` with that service. A `new ConverterService()` is also empty, so you can create as many as you like, for example one for each test.
+
+Register converters once, when the application starts. Each registration copies the registry's contents so that lookups can run without a lock. Registering is the slow step, and reading is the fast one. Both are safe to call from any thread.
+
+### Register and list
+
+`Register` files a converter under the `FromType` and `ToType` it reports. The pair is read once, at registration. `GetAllConverters` returns a copy of everything the registry holds. Later registrations do not change that copy. The excerpt counts the converters before and after one registration, so you can see the registry change.
+
+```csharp
+ConverterService service = new();
+
+Console.WriteLine(service.TypedConverters.GetAllConverters().Count());
+
+service.TypedConverters.Register(new DemoIntToStringConverter(LowAffinityScore));
+
+Console.WriteLine(service.TypedConverters.GetAllConverters().Count());
+```
+
+```text
+0
+1
+```
+
+### Resolve by affinity
+
+Several converters can share one pair. `TryGetConverter` asks each one for its affinity and returns the highest positive one, or `null` when the pair has no usable converter. On a tie, the converter registered first wins. This example registers a converter that scores 1 and another that scores 100.
+
+```csharp
+ConverterService service = new();
+service.TypedConverters.Register(new DemoIntToStringConverter(LowAffinityScore));
+service.TypedConverters.Register(new DemoIntToStringConverter(HighAffinityScore));
+
+var resolved = service.TypedConverters.TryGetConverter(typeof(int), typeof(string));
+
+Console.WriteLine(resolved!.GetAffinityForObjects());
+```
+
+```text
+100
+```
+
+### Override a built-in converter
+
+To replace a built-in converter, register one for the same pair with a higher affinity. `DefaultConverterRegistration.RegisterDefaults` adds the built-in typed converters to a service. This example registers `CustomBoolToStringConverter`, which scores 100 and writes `AFFIRMATIVE` and `NEGATIVE`.
+
+```csharp
+ConverterService service = new();
+DefaultConverterRegistration.RegisterDefaults(service);
+
+var builtIn = service.TypedConverters.TryGetConverter(typeof(bool), typeof(string));
+Console.WriteLine(builtIn!.GetType().Name);
+
+service.TypedConverters.Register(new CustomBoolToStringConverter());
+
+var resolved = service.TypedConverters.TryGetConverter(typeof(bool), typeof(string));
+var success = resolved!.TryConvertTyped(true, null, out var result);
+
+Console.WriteLine(resolved.GetType().Name);
+Console.WriteLine(success);
+Console.WriteLine(result);
+```
+
+```text
+BooleanToStringTypeConverter
+CustomBoolToStringConverter
+True
+AFFIRMATIVE
+```
+
+Give a replacement an affinity above 2. A converter that scores 2 or less loses to the built-in one, and a tie goes to the converter registered first. `RegisterDefaults` adds every converter each time you call it, so call it once. It registers no fallback or set-method converters.
+
+### Register in a service of your own
+
+`ResolveConverter` looks a converter up by type pair in a service. It asks the typed registry first and returns a converter for that pair when one applies. The excerpt registers one converter in a service of your own and resolves it by type pair. Nothing else in the process sees this service.
+
+```csharp
+ConverterService service = new();
+
+service.TypedConverters.Register(new PriorityColourConverter());
+
+var resolved = service.ResolveConverter(typeof(TodoPriority), typeof(string));
+
+Console.WriteLine(resolved!.GetType().Name);
+```
+
+```text
+PriorityColourConverter
+```
+
+### Use the registries without a service
+
+The three registries, `BindingTypeConverterRegistry`, `BindingFallbackConverterRegistry` and `SetMethodBindingConverterRegistry`, are public classes. You can create them without a `ConverterService` and register a converter in each. The excerpt does that, then asks each registry for the converter it holds. Use this when you need a single registry and no service.
+
+```csharp
+BindingTypeConverterRegistry typed = new();
+BindingFallbackConverterRegistry fallback = new();
+SetMethodBindingConverterRegistry setMethod = new();
+
+typed.Register(new PriorityColourConverter());
+fallback.Register(new CustomFallbackConverter());
+setMethod.Register(new DemoSetMethodConverter());
+
+Console.WriteLine(typed.TryGetConverter(typeof(TodoPriority), typeof(string))!.GetType().Name);
+Console.WriteLine(fallback.TryGetConverter(typeof(TodoPriority), typeof(string))!.GetType().Name);
+Console.WriteLine(setMethod.TryGetConverter(typeof(string), typeof(string))!.GetType().Name);
+```
+
+```text
+PriorityColourConverter
+CustomFallbackConverter
+DemoSetMethodConverter
+```
+
+### Register with the builder
+
+The application builder registers converters at start-up. `WithConverter`, `WithFallbackConverter` and `WithSetMethodConverter` each take one converter. `BuildApp` makes the configured service the shared `BindingConverters.Current`. The [setup page](setup.md) covers the builder. The excerpt registers one converter of each kind, builds the app and then reads all three back from the shared service.
+
+```csharp
+IReactiveUIBindingBuilder builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+_ = builder
+    .WithCoreServices()
+    .WithConverter(new PriorityColourConverter())
+    .WithFallbackConverter(new CustomFallbackConverter())
+    .WithSetMethodConverter(new DemoSetMethodConverter())
+    .BuildApp();
+
+var service = BindingConverters.Current;
+
+Console.WriteLine(service.TypedConverters.TryGetConverter(typeof(TodoPriority), typeof(string))!.GetType().Name);
+Console.WriteLine(service.FallbackConverters.TryGetConverter(typeof(TodoPriority), typeof(string))!.GetType().Name);
+Console.WriteLine(service.SetMethodConverters.TryGetConverter(typeof(string), typeof(string))!.GetType().Name);
+```
+
+```text
+PriorityColourConverter
+CustomFallbackConverter
+DemoSetMethodConverter
+```
+
+## Cover many type pairs with a fallback converter
+
+A typed converter matches one exact pair. A fallback converter covers a family of pairs with one rule. You implement `IBindingFallbackConverter`, which has two members. `GetAffinityForObjects` takes the two types and says whether the converter handles the pair. `TryConvert` does the conversion. The class below handles any conversion whose target is a `string`, whatever the source type is.
+
+```csharp
+public sealed class CustomFallbackConverter : IBindingFallbackConverter
+{
+    private const int FallbackAffinity = 1;
+
+    public int GetAffinityForObjects(Type fromType, Type toType) =>
+        toType == typeof(string) ? FallbackAffinity : 0;
+
+    public bool TryConvert(Type fromType, object from, Type toType, object? conversionHint, out object? result)
+    {
+        if (toType != typeof(string))
+        {
+            result = null;
+            return false;
+        }
+
+        result = from.ToString();
+        return result is not null;
+    }
+}
+```
+
+This converter turns any value into text with `ToString()`. It scores 1 when the target is `string` and 0 for every other target. A fallback converter must return a value that is not `null` when it returns `true`. The library treats a `null` result as a failed conversion. The library never passes it a `null` source value.
+
+The library registers no fallback converters of its own. Register yours in `FallbackConverters`, which has the same `Register`, `TryGetConverter` and `GetAllConverters` members as the typed registry. The excerpt registers the converter and counts what the fallback registry holds.
+
+```csharp
+ConverterService service = new();
+
+service.FallbackConverters.Register(new CustomFallbackConverter());
+
+Console.WriteLine(service.FallbackConverters.GetAllConverters().Count());
+```
+
+```text
+1
+```
+
+The registry picks the fallback converter the same way: highest positive affinity, and the earliest registered wins a tie. Affinity only ranks fallback converters against each other. The next excerpt asks the converter for its score on two pairs and converts a priority.
+
+```csharp
+ConverterService service = new();
+service.FallbackConverters.Register(new CustomFallbackConverter());
+
+var fallback = service.FallbackConverters.TryGetConverter(typeof(TodoPriority), typeof(string));
+
+Console.WriteLine(fallback!.GetAffinityForObjects(typeof(TodoPriority), typeof(string)));
+Console.WriteLine(fallback.GetAffinityForObjects(typeof(TodoPriority), typeof(int)));
+Console.WriteLine(fallback.TryConvert(typeof(TodoPriority), TodoPriority.High, typeof(string), null, out var text));
+Console.WriteLine(text);
+```
+
+```text
+1
+0
+True
+High
+```
+
+### Typed converters win over fallback converters
+
+`ConverterService.ResolveConverter` asks the typed registry first. It asks the fallback registry only when no typed converter applies. A typed converter always wins, whatever the affinities are. It returns `null` when neither registry has a match. The return type is `object?`, because the result is either an `IBindingTypeConverter` or an `IBindingFallbackConverter`. The excerpt resolves three type pairs from one service. Each pair shows a different outcome.
+
+```csharp
+ConverterService service = new();
+DefaultConverterRegistration.RegisterDefaults(service);
+service.FallbackConverters.Register(new CustomFallbackConverter());
+
+var forInteger = service.ResolveConverter(typeof(int), typeof(string));
+var forPriority = service.ResolveConverter(typeof(TodoPriority), typeof(string));
+var forGuid = service.ResolveConverter(typeof(TodoPriority), typeof(Guid));
+
+Console.WriteLine(forInteger!.GetType().Name);
+Console.WriteLine(forPriority!.GetType().Name);
+Console.WriteLine(forGuid is null);
+```
+
+```text
+IntegerToStringTypeConverter
+CustomFallbackConverter
+True
+```
+
+The `int` to `string` pair has a built-in typed converter, so the fallback converter never sees it. `TodoPriority` to `string` has none, so the fallback converter answers. `TodoPriority` to `Guid` has no typed converter and the fallback converter scores 0 for it, so nothing answers.
+
+## Replace how a binding writes
+
+A set-method converter changes the write step of a binding. A binding normally assigns the new value to the target property. A set-method converter can do something else instead, such as fill a collection with the new items. Implement `ISetMethodBindingConverter`, which has two members.
+
+- `GetAffinityForObjects` ranks the converter for the type of the value and the type of the target. Either type can be `null`.
+- `PerformSet` writes the value. It takes the target, the new value and the index arguments for an indexer. It returns the result of the write. The class below is the smallest useful one. It scores 1 for every pair and returns the new value unchanged.
+
+```csharp
+public sealed class DemoSetMethodConverter : ISetMethodBindingConverter
+{
+    private const int SetMethodAffinity = 1;
+
+    public int GetAffinityForObjects(Type? fromType, Type? toType) => SetMethodAffinity;
+
+    public object? PerformSet(object? toTarget, object? newValue, object?[]? arguments) => newValue;
+}
+```
+
+Register it in `SetMethodConverters`. `ResolveSetMethodConverter` on the service picks the best one for a pair of types, with the same rule as the other registries. Its registry has the same `Register`, `TryGetConverter` and `GetAllConverters` members. The excerpt registers the converter, resolves it for a pair of strings and calls `PerformSet` on it.
+
+```csharp
+ConverterService service = new();
+service.SetMethodConverters.Register(new DemoSetMethodConverter());
+
+var converter = service.ResolveSetMethodConverter(typeof(string), typeof(string));
+
+Console.WriteLine(converter!.GetType().Name);
+Console.WriteLine(converter.PerformSet(null, "Renew car registration", null));
+```
+
+```text
+DemoSetMethodConverter
+Renew car registration
+```
+
+`GetAllConverters` counts what the set-method registry holds, the same check the typed and fallback registries offer.
+
+```csharp
+ConverterService service = new();
+
+service.SetMethodConverters.Register(new DemoSetMethodConverter());
+
+Console.WriteLine(service.SetMethodConverters.GetAllConverters().Count());
+```
+
+```text
+1
+```
+
+A set-method converter usually applies to one kind of target. Return 0 for the others. `LegacyTagListSetMethodConverter` fills a `List<string>` instead of replacing it, so it applies only when the target is one. The excerpt asks it for its score on three pairs. A generated collection write passes `null` for the index arguments. It casts the returned value to the target type and reports it as the new value.
+
+```csharp
+ConverterService service = new();
+service.SetMethodConverters.Register(new LegacyTagListSetMethodConverter());
+
+var converter = service.ResolveSetMethodConverter(typeof(IReadOnlyList<string>), typeof(List<string>))!;
+
+Console.WriteLine(converter.GetAffinityForObjects(typeof(IReadOnlyList<string>), typeof(List<string>)));
+Console.WriteLine(converter.GetAffinityForObjects(typeof(string), typeof(string)));
+Console.WriteLine(converter.GetAffinityForObjects(fromType: null, toType: null));
+```
+
+```text
+5
+0
+0
+```
+
+The score is 5 for the tag list pair, 0 for two strings and 0 when both types are `null`. The migration section below shows this converter at work.
+
+## Migrate converters from ReactiveUI
+
+An app built on ReactiveUI registers its binding converters with a Splat resolver. Splat is the library ReactiveUI uses to register a service once and look it up by type later. Moving that app to ReactiveUI.Binding leaves you with converters you wrote and tested. You do not rewrite them.
+
+ReactiveUI's reflection engine takes its converters from the Splat resolver. ReactiveUI.Binding takes them from a `ConverterService`, and generated bindings read `BindingConverters.Current`. A converter that sits only in the resolver is never asked. The migration helpers read the resolver once and copy what it holds into a service.
+
+The resolver must hold registrations of this library's `IBindingTypeConverter`, `IBindingFallbackConverter` and `ISetMethodBindingConverter`. The helpers ask the resolver for those three service types. The example project builds a resolver that holds one converter of each kind, registered the way a ReactiveUI app registers them. The method below is that setup. The steps that follow read from the resolver it returns.
+
+```csharp
+public static ModernDependencyResolver Create()
+{
+    ModernDependencyResolver resolver = new();
+
+    resolver.RegisterConstant<IBindingTypeConverter>(new LegacyPriorityToColorConverter());
+    resolver.RegisterConstant<IBindingFallbackConverter>(new LegacyObjectToStringFallbackConverter());
+    resolver.RegisterConstant<ISetMethodBindingConverter>(new LegacyTagListSetMethodConverter());
+
+    return resolver;
+}
+```
+
+**1. Read the converters.** `ConverterMigrationHelper.ExtractConverters` returns the typed, fallback and set-method converters that the resolver holds. It registers nothing. It skips a `null` registration and keeps the order the resolver returns. The result is an `ExtractedConverters` record with one list for each kind. The excerpt reads the resolver and prints how many converters of each kind it found and their class names.
+
+```csharp
+using var legacyResolver = LegacyAppDependencyResolver.Create();
+
+var extracted = ConverterMigrationHelper.ExtractConverters(legacyResolver);
+
+Console.WriteLine(extracted.TypedConverters.Count);
+Console.WriteLine(extracted.FallbackConverters.Count);
+Console.WriteLine(extracted.SetMethodConverters.Count);
+Console.WriteLine(extracted.TypedConverters[0].GetType().Name);
+Console.WriteLine(extracted.FallbackConverters[0].GetType().Name);
+Console.WriteLine(extracted.SetMethodConverters[0].GetType().Name);
+```
+
+```text
+1
+1
+1
+LegacyPriorityToColorConverter
+LegacyObjectToStringFallbackConverter
+LegacyTagListSetMethodConverter
+```
+
+**2. Copy them into a service.** `ImportFrom` is an extension on `ConverterService`. It extracts the three kinds and registers each converter with the matching registry. Each converter keeps its behaviour: the typed one maps `TodoPriority.High` to `#D32F2F`, the fallback one shows an `IssueState` as its text and the set-method one fills the list. The excerpt imports into a new service, then uses one converter of each kind to prove the copy worked.
+
+```csharp
+using var legacyResolver = LegacyAppDependencyResolver.Create();
+ConverterService service = new();
+
+service.ImportFrom(legacyResolver);
+
+var typed = service.TypedConverters.TryGetConverter(typeof(TodoPriority), typeof(string));
+Console.WriteLine(typed!.TryConvertTyped(TodoPriority.High, null, out var highColour));
+Console.WriteLine(highColour);
+
+var fallback = service.FallbackConverters.TryGetConverter(typeof(IssueState), typeof(string));
+Console.WriteLine(fallback!.TryConvert(typeof(IssueState), IssueState.Closed, typeof(string), null, out var stateText));
+Console.WriteLine(stateText);
+
+var setMethod = service.SetMethodConverters.TryGetConverter(typeof(IReadOnlyList<string>), typeof(List<string>));
+List<string> tagList = ["draft"];
+List<string> newTags = ["travel", "admin"];
+
+_ = setMethod!.PerformSet(tagList, newTags, null);
+
+Console.WriteLine(string.Join(", ", tagList));
+```
+
+```text
+True
+#D32F2F
+True
+Closed
+travel, admin
+```
+
+The import is a one-time copy. A converter that you add to the resolver later does not reach the service. Import after the resolver is complete.
+
+**3. Import into the shared service.** The next two examples import into `BindingConverters.Current`, which is the service that bindings use when you do not hand them another one. The first passes the migrated converter to `BindTo` as the converter override.
+
+```csharp
+using var legacyResolver = LegacyAppDependencyResolver.Create();
+
+BindingConverters.Current.ImportFrom(legacyResolver);
+
+var migrated = BindingConverters.Current.TypedConverters.TryGetConverter(typeof(TodoPriority), typeof(string));
+TodoItem item = new() { Title = "Renew passport", Priority = TodoPriority.High };
+Label priorityBadge = new();
+
+using (item.WhenChanged(x => x.Priority).BindTo(priorityBadge, x => x.Text, migrated!))
+{
+    Console.WriteLine(priorityBadge.Text);
+
+    item.Priority = TodoPriority.Low;
+
+    Console.WriteLine(priorityBadge.Text);
+}
+```
+
+```text
+#D32F2F
+#9E9E9E
+```
+
+The second leaves the converter out. The binding looks in the same service and takes the converter with the highest affinity for the two types. Prefer this form. Import once at start-up, and every binding that needs a migrated converter finds it.
+
+```csharp
+using var legacyResolver = LegacyAppDependencyResolver.Create();
+
+BindingConverters.Current.ImportFrom(legacyResolver);
+
+TodoItem item = new() { Title = "Book dentist", Priority = TodoPriority.Normal };
+Label priorityBadge = new();
+
+using (item.WhenChanged(x => x.Priority).BindTo(priorityBadge, x => x.Text))
+{
+    Console.WriteLine(priorityBadge.Text);
+
+    item.Priority = TodoPriority.High;
+
+    Console.WriteLine(priorityBadge.Text);
+}
+```
+
+```text
+#FB8C00
+#D32F2F
+```
+
+The legacy converter scores 100, so it wins over any built-in converter for its pair.
+
+**4. Work with `ExtractedConverters`.** The record is public, and you can build one yourself. It deconstructs into its three lists. The excerpt builds one from three single-item lists, takes it apart again and prints the class name of each converter.
+
+```csharp
+List<IBindingTypeConverter> typed = [new LegacyPriorityToColorConverter()];
+List<IBindingFallbackConverter> fallback = [new LegacyObjectToStringFallbackConverter()];
+List<ISetMethodBindingConverter> setMethod = [new LegacyTagListSetMethodConverter()];
+ExtractedConverters extracted = new(typed, fallback, setMethod);
+
+var (typedConverters, fallbackConverters, setMethodConverters) = extracted;
+
+Console.WriteLine(typedConverters[0].GetType().Name);
+Console.WriteLine(fallbackConverters[0].GetType().Name);
+Console.WriteLine(setMethodConverters[0].GetType().Name);
+```
+
+```text
+LegacyPriorityToColorConverter
+LegacyObjectToStringFallbackConverter
+LegacyTagListSetMethodConverter
+```
+
+It is a `record`, so two results are equal when they hold the same three lists, and `with` copies one. This excerpt compares a result with a copy and with a copy that has no fallback converters. It also checks `Equals`, `GetHashCode` and `ToString`.
+
+```csharp
+using var legacyResolver = LegacyAppDependencyResolver.Create();
+var extracted = ConverterMigrationHelper.ExtractConverters(legacyResolver);
+var same = extracted with { };
+var withoutFallback = extracted with { FallbackConverters = [] };
+object boxedSame = same;
+
+Console.WriteLine(extracted == same);
+Console.WriteLine(extracted != withoutFallback);
+Console.WriteLine(extracted.Equals(same));
+Console.WriteLine(extracted.Equals(boxedSame));
+Console.WriteLine(extracted.GetHashCode() == same.GetHashCode());
+Console.WriteLine(extracted.ToString().StartsWith(nameof(ExtractedConverters), StringComparison.Ordinal));
+```
+
+```text
+True
+True
+True
+True
+True
+True
+```
+
+### Where this differs from ReactiveUI
+
+- **Where converters live.** ReactiveUI's reflection engine takes its converters from the Splat resolver. ReactiveUI.Binding takes them from a `ConverterService`, and `ImportFrom` copies them across.
+- **How many services exist.** A Splat resolver is usually the one global locator. You can create any number of `ConverterService` objects, each with its own registries.
+- **Late registrations.** The import copies what the resolver holds at that moment. A converter registered with the resolver after the import does not reach the service.
+
+## Pair two conversions
+
+A two-way binding needs a conversion for each direction. `TwoWayConverterPair<TSourceProp, TTargetProp>` is a `record` that holds the two conversions as delegates. `Forward` converts a source value to the target type. `Reverse` converts a target value back. The runtime binding methods in `ReactiveUI.Binding.Fallback` take a pair. The type is public but hidden from IntelliSense. `TwoWayConverters.Create` builds a pair without naming its type arguments. A pair deconstructs into `Forward` and `Reverse`. The excerpt pairs a priority-to-text conversion with a text-to-priority one, takes the pair apart and calls each half.
+
+```csharp
+Func<TodoPriority, string> toText = static priority => priority.ToString();
+Func<string, TodoPriority> toPriority = Enum.Parse<TodoPriority>;
+TwoWayConverterPair<TodoPriority, string> pair = new(toText, toPriority);
+
+var (forward, reverse) = pair;
+
+Console.WriteLine(forward(TodoPriority.High));
+Console.WriteLine(reverse("Low"));
+```
+
+```text
+High
+Low
+```
+
+Two pairs are equal when they hold the same two delegates. A pair with a different delegate is not equal. The excerpt also checks `Equals`, `GetHashCode` and `ToString`.
+
+```csharp
+Func<TodoPriority, string> toText = static priority => priority.ToString();
+Func<string, TodoPriority> toPriority = Enum.Parse<TodoPriority>;
+TwoWayConverterPair<TodoPriority, string> pair = new(toText, toPriority);
+TwoWayConverterPair<TodoPriority, string> same = new(toText, toPriority);
+TwoWayConverterPair<TodoPriority, string> different = new(toText, static _ => TodoPriority.Low);
+object boxedSame = same;
+
+Console.WriteLine(pair == same);
+Console.WriteLine(pair != different);
+Console.WriteLine(pair.Equals(boxedSame));
+Console.WriteLine(pair.GetHashCode() == same.GetHashCode());
+Console.WriteLine(pair.ToString().StartsWith(nameof(TwoWayConverterPair<,>), StringComparison.Ordinal));
+```
+
+```text
+True
+True
+True
+True
+True
+```
+
+## Next steps
+
+- [Converters](converters.md) covers the built-in converters.
+- [Bindings](bindings.md) covers the binding methods that take a converter.
+- [Views](views.md) covers the view locator that `AccountsToViewsConverter` calls.
+- [Setup](setup.md) covers the builder that registers converters at start-up.
+- [Unsafe](unsafe.md) covers the reflection-based twins of the binding methods.
+
+## API reference
+
+The table lists the public members of the converter contracts, the registries, the builder methods and the migration helpers. The built-in converters are on the [converters page](converters.md). The generated [API reference](api.md) lists every signature.
+
+| Member | What it does | Type and values | Notes |
+| --- | --- | --- | --- |
+| [`IBindingTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/IBindingTypeConverter.cs) | Converts a boxed value from one type to another for the binding methods. | Interface that also implements `IEnableLogger`. | Register an implementation to teach a binding a type pair. |
+| [`IBindingTypeConverter.FromType`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/IBindingTypeConverter.cs) | Gets the source type the converter accepts. | Read-only `Type`. | A registry reads it once, at registration. |
+| [`IBindingTypeConverter.ToType`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/IBindingTypeConverter.cs) | Gets the target type the converter produces. | Read-only `Type`. | A registry reads it once, at registration. |
+| [`IBindingTypeConverter.GetAffinityForObjects`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/IBindingTypeConverter.cs) | Scores the converter against others for the same type pair. | Returns `int`. | A positive value means the converter applies. Zero or less excludes it. The highest value wins, and the earliest registered converter wins a tie. |
+| [`IBindingTypeConverter.TryConvertTyped`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/IBindingTypeConverter.cs) | Converts a boxed value. | Takes `object? from` and `object? conversionHint`. Returns `bool` and an `object?` result. | Returns `false` on failure, and the result is `null`. A `null` source is accepted only when the converter can convert `null`. |
+| [`IBindingTypeConverter<TFrom, TTo>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/IBindingTypeConverter%7BTFrom,TTo%7D.cs) | Adds a typed conversion for one type pair. | Interface. `TFrom` is contravariant. | Generated bindings call the typed method when they can, so a value type is not boxed. |
+| [`IBindingTypeConverter<TFrom, TTo>.TryConvert`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/IBindingTypeConverter%7BTFrom,TTo%7D.cs) | Converts a value without boxing. | Takes `TFrom? from` and `object? conversionHint`. Returns `bool` and a `TTo?` result. | The result can be `null` on success when the target type is nullable. |
+| [`BindingTypeConverter<TFrom, TTo>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingTypeConverter.cs) | Base class for a converter between one type pair. | Abstract class with a protected constructor. | Supplies `FromType` as `typeof(TFrom)`, `ToType` as `typeof(TTo)` and `TryConvertTyped`. |
+| [`BindingTypeConverter<TFrom, TTo>.GetAffinityForObjects`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingTypeConverter.cs) | Scores the converter. You override it. | Abstract. Returns `int`. | The built-in converters return 2 and the equality converter returns 1, so a larger value outranks them. |
+| [`BindingTypeConverter<TFrom, TTo>.TryConvert`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingTypeConverter.cs) | Converts one value. You override it. | Abstract. Takes `TFrom? from` and `object? conversionHint`. Returns `bool` and a `TTo?` result. | Return `false` when the value cannot be converted. |
+| [`BindingTypeConverter<TFrom, TTo>.TryConvertTyped`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingTypeConverter.cs) | Converts a boxed value by casting it to `TFrom` and calling `TryConvert`. | Takes `object? from` and `object? conversionHint`. Returns `bool` and an `object?` result. | Returns `false` when the value is not a `TFrom`. A `null` source becomes `default` when `TFrom` can hold `null`, and fails when it cannot. The hint passes through unchanged. |
+| [`IBindingFallbackConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/IBindingFallbackConverter.cs) | Converts type pairs that no typed converter covers. | Interface that also implements `IEnableLogger`. | The converter service asks fallback converters only when no typed converter applies. The library registers none. |
+| [`IBindingFallbackConverter.GetAffinityForObjects`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/IBindingFallbackConverter.cs) | Scores the converter for a runtime type pair. | Takes `Type fromType` and `Type toType`. Returns `int`. | A positive value means the converter handles the pair. Zero or less means it does not. The score ranks fallback converters against each other only. |
+| [`IBindingFallbackConverter.TryConvert`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/IBindingFallbackConverter.cs) | Converts a value to the target type. | Takes `Type fromType`, `object from`, `Type toType` and `object? conversionHint`. Returns `bool` and an `object?` result. | The library never passes `null` as the source. A `true` return with a `null` result counts as a failed conversion. |
+| [`ISetMethodBindingConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/ISetMethodBindingConverter.cs) | Replaces how a binding writes a value to its target, for example to fill a collection. | Interface that also implements `IEnableLogger`. | Register it in the set-method registry. |
+| [`ISetMethodBindingConverter.GetAffinityForObjects`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/ISetMethodBindingConverter.cs) | Scores the converter for writing one type to a target of another type. | Takes `Type? fromType` and `Type? toType`. Returns `int`. | Both types can be `null`. Zero or less excludes the converter. |
+| [`ISetMethodBindingConverter.PerformSet`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/ISetMethodBindingConverter.cs) | Writes a value to the target. | Takes `object? toTarget`, `object? newValue` and `object?[]? arguments`. Returns `object?`. | `arguments` holds the index arguments of an indexer target. A generated collection write passes `null` and casts the returned value to the target type. |
+| [`ConverterService`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ConverterService.cs) | Owns the three registries and resolves the best converter for a type pair. | Sealed class with a public parameterless constructor. | A new service is empty. |
+| [`ConverterService.TypedConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ConverterService.cs) | Gets the registry of typed converters. | Read-only `BindingTypeConverterRegistry`. | Each converter matches one exact source and target pair. |
+| [`ConverterService.FallbackConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ConverterService.cs) | Gets the registry of fallback converters. | Read-only `BindingFallbackConverterRegistry`. | Consulted when no typed converter applies. |
+| [`ConverterService.SetMethodConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ConverterService.cs) | Gets the registry of set-method converters. | Read-only `SetMethodBindingConverterRegistry`. | These converters replace the write step of a binding. |
+| [`ConverterService.ResolveConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ConverterService.cs) | Returns the best typed converter for the pair, or else the best fallback converter. | Takes `Type fromType` and `Type toType`. Returns `object?`. | A typed converter always wins, whatever the affinities. The result is an `IBindingTypeConverter`, an `IBindingFallbackConverter` or `null`. Throws `ArgumentNullException` when either type is `null`. |
+| [`ConverterService.ResolveSetMethodConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ConverterService.cs) | Returns the best set-method converter for the pair. | Takes `Type? fromType` and `Type? toType`. Returns `ISetMethodBindingConverter?`. | Both types can be `null`. Returns `null` when no converter has a positive affinity. |
+| [`BindingConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/BindingConverters.cs) | Holds the process-wide converter service that generated and runtime bindings use. | Static class. | The builder's `BuildApp` replaces the service. |
+| [`BindingConverters.Current`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/BindingConverters.cs) | Gets the converter service in use. | Read-only `ConverterService`. | Starts empty. It holds the built-in converters only after the builder publishes its service. |
+| [`BindingTypeConverterRegistry`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/BindingTypeConverterRegistry.cs) | Holds typed converters grouped by exact source and target type pair. | Sealed class with a public parameterless constructor. | Each registration copies the registry, so registering is slow and lookups are fast. Safe to call from any thread. |
+| [`BindingTypeConverterRegistry.Register`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/BindingTypeConverterRegistry.cs) | Files a converter under its `FromType` and `ToType`. | Takes `IBindingTypeConverter converter`. Returns nothing. | Several converters can share a pair. Throws `ArgumentNullException` for `null`. |
+| [`BindingTypeConverterRegistry.TryGetConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/BindingTypeConverterRegistry.cs) | Returns the converter with the highest positive affinity for the exact pair. | Takes `Type fromType` and `Type toType`. Returns `IBindingTypeConverter?`. | The earliest registered converter wins a tie. Returns `null` when none is registered or every one scores zero or less. Throws `ArgumentNullException` when either type is `null`. |
+| [`BindingTypeConverterRegistry.GetAllConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/BindingTypeConverterRegistry.cs) | Returns a copy of every registered converter. | Returns `IEnumerable<IBindingTypeConverter>`. | Empty when none are registered. A registration made after the call does not change the copy. The order across type pairs is not defined. |
+| [`BindingFallbackConverterRegistry`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/BindingFallbackConverterRegistry.cs) | Holds fallback converters, which the registry asks about a type pair at lookup time. | Sealed class with a public parameterless constructor. | Same locking model as the typed registry. |
+| [`BindingFallbackConverterRegistry.Register`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/BindingFallbackConverterRegistry.cs) | Adds a fallback converter. | Takes `IBindingFallbackConverter converter`. Returns nothing. | Throws `ArgumentNullException` for `null`. |
+| [`BindingFallbackConverterRegistry.TryGetConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/BindingFallbackConverterRegistry.cs) | Asks each converter for its affinity and returns the highest positive one. | Takes `Type fromType` and `Type toType`. Returns `IBindingFallbackConverter?`. | The earliest registered converter wins a tie. Returns `null` when none scores above zero. Throws `ArgumentNullException` when either type is `null`. |
+| [`BindingFallbackConverterRegistry.GetAllConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/BindingFallbackConverterRegistry.cs) | Returns a copy of every registered fallback converter. | Returns `IEnumerable<IBindingFallbackConverter>`. | Registration order. Empty when none are registered. |
+| [`SetMethodBindingConverterRegistry`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/SetMethodBindingConverterRegistry.cs) | Holds set-method converters, which the registry asks about a type pair at lookup time. | Sealed class with a public parameterless constructor. | Same locking model as the typed registry. |
+| [`SetMethodBindingConverterRegistry.Register`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/SetMethodBindingConverterRegistry.cs) | Adds a set-method converter. | Takes `ISetMethodBindingConverter converter`. Returns nothing. | Throws `ArgumentNullException` for `null`. |
+| [`SetMethodBindingConverterRegistry.TryGetConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/SetMethodBindingConverterRegistry.cs) | Asks each converter for its affinity and returns the highest positive one. | Takes `Type? fromType` and `Type? toType`. Returns `ISetMethodBindingConverter?`. | Both types can be `null`. The earliest registered converter wins a tie. Returns `null` when none scores above zero. |
+| [`SetMethodBindingConverterRegistry.GetAllConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/SetMethodBindingConverterRegistry.cs) | Returns a copy of every registered set-method converter. | Returns `IEnumerable<ISetMethodBindingConverter>`. | Registration order. Empty when none are registered. |
+| [`DefaultConverterRegistration`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/DefaultConverterRegistration.cs) | Registers the built-in typed converters with a service. | Static class. | Registers no fallback or set-method converters. |
+| [`DefaultConverterRegistration.RegisterDefaults`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/DefaultConverterRegistration.cs) | Adds the string, equality, boolean, `Guid`, `Uri`, numeric, and date and time converters, each with its nullable forms. | Takes `ConverterService service`. Returns nothing. | Each call adds every converter again. `DateOnly` and `TimeOnly` converters exist on .NET 8 and later. Throws `ArgumentNullException` for `null`. |
+| [`IReactiveUIBindingBuilder.WithConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/IReactiveUIBindingBuilder.cs) | Registers a typed converter in the builder's service. | Takes `IBindingTypeConverter converter`. Returns `IReactiveUIBindingBuilder`. | `ReactiveUIBindingBuilder` implements it, and throws `ArgumentNullException` for `null`. [`BuilderMixins`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/BuilderMixins.cs) adds the same method on `IAppBuilder`, which throws `InvalidOperationException` when the app builder is not a binding builder. |
+| [`IReactiveUIBindingBuilder.WithFallbackConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/IReactiveUIBindingBuilder.cs) | Registers a fallback converter in the builder's service. | Takes `IBindingFallbackConverter converter`. Returns `IReactiveUIBindingBuilder`. | Same null and receiver rules as `WithConverter`. |
+| [`IReactiveUIBindingBuilder.WithSetMethodConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/IReactiveUIBindingBuilder.cs) | Registers a set-method converter in the builder's service. | Takes `ISetMethodBindingConverter converter`. Returns `IReactiveUIBindingBuilder`. | Same null and receiver rules as `WithConverter`. |
+| [`ConverterMigrationHelper`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ConverterMigrationHelper.cs) | Reads converters registered with a Splat dependency resolver. | Static class. | Registers nothing. |
+| [`ConverterMigrationHelper.ExtractConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ConverterMigrationHelper.cs) | Collects the typed, fallback and set-method converters the resolver holds. | Takes `IReadonlyDependencyResolver resolver`. Returns `ExtractedConverters`. | Keeps the order the resolver returns and skips a `null` registration. Throws `ArgumentNullException` for a `null` resolver. |
+| [`ConverterMigrationHelperMixins.ImportFrom`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ConverterMigrationHelperMixins.cs) | Extension member on `ConverterService` that registers the resolver's converters with the matching registries. | Takes `IReadonlyDependencyResolver resolver`. Returns nothing. | A one-time copy. A converter added to the resolver after the call does not reach the service. Throws `ArgumentNullException` for a `null` service or resolver. |
+| [`ExtractedConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ExtractedConverters.cs) | Groups the converters found in a resolver by the role each one fills. | Sealed record. The constructor takes the three lists in the order typed, fallback, set-method. | Two results are equal when they hold the same three lists. Deconstructs into the three lists. |
+| [`ExtractedConverters.TypedConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ExtractedConverters.cs) | Holds the converters that move a value between two known types. | `IList<IBindingTypeConverter>`, init-only. | Empty when the resolver holds none. |
+| [`ExtractedConverters.FallbackConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ExtractedConverters.cs) | Holds the converters asked when no typed converter matches. | `IList<IBindingFallbackConverter>`, init-only. | Empty when the resolver holds none. |
+| [`ExtractedConverters.SetMethodConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/Converters/ExtractedConverters.cs) | Holds the converters that write a value to a target. | `IList<ISetMethodBindingConverter>`, init-only. | Empty when the resolver holds none. |
+| [`TwoWayConverterPair<TSourceProp, TTargetProp>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/TwoWayConverterPair.cs) | Holds the two conversions a two-way binding needs. | Sealed record. The constructor takes `Forward` and `Reverse`. | Hidden from IntelliSense. Two pairs are equal when they hold the same two delegates. |
+| [`TwoWayConverterPair.Forward`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/TwoWayConverterPair.cs) | Converts a source value to the target type. | `Func<TSourceProp, TTargetProp>`, init-only. | Read by deconstructing the pair as well. |
+| [`TwoWayConverterPair.Reverse`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/TwoWayConverterPair.cs) | Converts a target value back to the source type. | `Func<TTargetProp, TSourceProp>`, init-only. | Read by deconstructing the pair as well. |
+| [`TwoWayConverters`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/TwoWayConverters.cs) | Builds a `TwoWayConverterPair` without naming its type arguments. | Static class. | Hidden from IntelliSense. |
+| [`TwoWayConverters.Create`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/TwoWayConverters.cs) | Pairs a forward and a reverse conversion. | Takes `Func<TSourceProp, TTargetProp> forward` and `Func<TTargetProp, TSourceProp> reverse`. Returns `TwoWayConverterPair<TSourceProp, TTargetProp>`. | The type arguments come from the arguments. |
diff --git a/docs/documentation/binding/index.md b/docs/documentation/binding/index.md
new file mode 100644
index 00000000..2afb949a
--- /dev/null
+++ b/docs/documentation/binding/index.md
@@ -0,0 +1,233 @@
+---
+Order: 1
+---
+# ReactiveUI.Binding
+
+[Run the complete page example](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/index/index.csproj).
+
+A screen shows data that changes. When the title of a to-do item changes, the label that shows it must change too.
+When the user types in a box, the view model must learn the new text.
+Writing that code by hand means an event handler for every pair of properties, and a handler you forget to remove.
+
+ReactiveUI.Binding keeps a view and a view model in step. You write one line that names the two properties,
+and the library does the listening, the copying and the cleanup.
+
+A **source generator** is a compiler add-on that writes code while your project builds. ReactiveUI.Binding reads
+each place where you observe or bind a property and writes the code for that place. Nothing looks up
+a property by name at run time. The result is safe to trim and to publish with Native AOT,
+and a binding costs little to create and to run.
+
+The generated code takes part in your build like any file you wrote. You can read it,
+step through it in a debugger, and the compiler checks it against your types.
+
+## Install
+
+Install the `ReactiveUI.Binding` NuGet package in your view model project and in your view project.
+The package carries the runtime library, the source generator and an analyzer. The analyzer reports
+binding calls that the generator cannot handle, as you type.
+
+```bash
+dotnet add package ReactiveUI.Binding
+```
+
+The example on this page shows a label from .NET MAUI, so its project also references the MAUI package,
+`ReactiveUI.Binding.Maui`. [Threading and platforms](threading.md) explains what the platform packages add.
+[Setup](setup.md) covers the builder, the analyzer and Native AOT.
+
+These examples use .NET 10 and C# 14. They run against a store that keeps its data in memory,
+so you can run them as they are.
+
+## Your first binding
+
+The walkthrough below uses a to-do screen. `TodoListViewModel` loads items from a store and counts how many
+are left to do. `TodoView` holds the controls, among them a `RemainingLabel` that should show that count.
+A real UI framework builds the controls from markup. The example view creates them in code.
+
+**1. Load a view model.** The code below creates the view model with an in-memory store and loads its items.
+A binding needs data to show, so this gives the later steps four to-do items to work with.
+
+```csharp
+var viewModel = new TodoListViewModel(InMemoryTodoStore.CreateSeeded());
+
+await viewModel.LoadAsync();
+
+Console.WriteLine(viewModel.Items.Count);
+```
+
+```text
+4
+```
+
+**2. Observe a property.** `WhenChanged` takes a lambda that names a property and returns a stream of that property's values.
+The stream is an `IObservable<T>`. Nothing happens until you **subscribe**. A subscription starts the listening and
+tells the stream what to do with each value.
+
+The code below watches the title of the first item and prints every title the stream delivers.
+It then renames the item, so you can see the stream report the change without any polling.
+
+```csharp
+var viewModel = new TodoListViewModel(InMemoryTodoStore.CreateSeeded());
+await viewModel.LoadAsync();
+var registration = viewModel.Items[0];
+
+using (registration.WhenChanged(static x => x.Title).Subscribe(Console.WriteLine))
+{
+    registration.Title = RenamedTitle;
+}
+```
+
+The first value is the current title. Later values arrive each time the title changes.
+The example prints the current title, then the new one.
+
+```text
+Renew car registration
+Renew car registration online
+```
+
+The lambda is `static x => x.Title`. Mark a lambda `static` when it uses nothing from the method around it.
+The generator reads the lambda's text at build time, so the lambda has to be written inline at the call.
+The `Subscribe` overload that takes a delegate comes from `ReactiveUI.Primitives`, which the example imports with a `using`.
+
+`Subscribe` returns an `IDisposable`. Disposing it ends the subscription. The `using` statement disposes it at the closing brace,
+so the subscription is gone when the block ends. Dispose every subscription you create.
+A subscription you keep alive holds the object it listens to in memory.
+
+The [Observing](observing.md) page covers watching one to sixteen properties at once, paths that cross several objects,
+and the before-change form, `WhenChanging`.
+
+**3. Bind a property to a control.** `BindOneWay` copies a view model property to a view property and keeps the copy up to date.
+The code below shows the number of unfinished items in a label, then finishes an item.
+You never write the update yourself: the label follows the view model.
+
+```csharp
+var viewModel = new TodoListViewModel(InMemoryTodoStore.CreateSeeded());
+var view = new TodoView();
+await viewModel.LoadAsync();
+
+using (viewModel.BindOneWay(view, static x => x.RemainingCount, static v => v.RemainingLabel.Text, static count => count.ToString(CultureInfo.InvariantCulture)))
+{
+    Console.WriteLine(view.RemainingLabel.Text);
+
+    viewModel.SelectedItem = viewModel.Items[0];
+    await viewModel.CompleteAsync();
+
+    Console.WriteLine(view.RemainingLabel.Text);
+}
+```
+
+The label shows the count the moment the binding is created. It shows a new count each time an item is finished.
+The example selects the first item and finishes it, so the count falls from three to two.
+
+```text
+3
+2
+```
+
+The call takes the view model, which is the source, and the view, which is the target.
+Two lambdas name the properties. `RemainingCount` is an `int` and the label's `Text` is a `string`, so
+the last argument converts one to the other. The example adds `using System.Globalization;` for `CultureInfo`.
+
+The target lambda, `static v => v.RemainingLabel.Text`, is a path. A **property path** is a chain of properties,
+here `RemainingLabel` and then `Text`. A binding follows each link of the chain. If a link on the way changes,
+the binding moves to the new object.
+
+The binding also picks the thread it writes on. A UI framework lets only one thread change a control.
+`BindOneWay` writes to the target on the thread that owns it. [Threading and platforms](threading.md) shows how.
+
+**4. Stop the binding.** `BindOneWay` returns an `IDisposable`, the same as `Subscribe`.
+Dispose it to stop the binding.
+The code below creates a binding, disposes it at once, and then finishes an item.
+It shows that a disposed binding stops writing to the view, so a screen that closes leaves nothing behind.
+
+```csharp
+var binding = viewModel.BindOneWay(view, static x => x.RemainingCount, static v => v.RemainingLabel.Text, static count => count.ToString(CultureInfo.InvariantCulture));
+binding.Dispose();
+
+viewModel.SelectedItem = viewModel.Items[0];
+await viewModel.CompleteAsync();
+
+Console.WriteLine(view.RemainingLabel.Text);
+```
+
+The label keeps the text it had when the binding was disposed. Finishing an item no longer changes it.
+
+```text
+3
+```
+
+## What happens at build time
+
+For each call to `WhenChanged`, `BindOneWay` and the other binding methods, the generator writes a method
+that does the work for that call. It reads the property names from your lambdas and picks the way to
+listen for changes from the types of the objects. A type that implements `INotifyPropertyChanged`
+announces a change by raising its `PropertyChanged` event. Other types announce changes in other ways.
+The [Mechanisms](mechanisms.md) page explains how the generator picks one.
+
+The generated method reaches your call in one of two ways. On a compiler that supports interceptors,
+the compiler replaces your call with the generated method. Otherwise the generator adds an overload
+that the compiler picks in place of the library's own method. Both ways run the generated code.
+Your source stays as you wrote it.
+
+The library's own methods, such as the `WhenChanged` you call, are stubs. A stub throws an
+`InvalidOperationException` when it runs, and the message names the `Unsafe` overload to use instead.
+You meet the stub when a call site is one the generator cannot read, for example when you pass a lambda that
+you built earlier and stored in a variable. The analyzer reports such a call while you edit,
+with a diagnostic whose id starts with `RXUIBIND`. [Setup](setup.md) lists the diagnostics.
+
+The `Unsafe` overloads find properties by reflection while the program runs. They accept expressions
+the generator cannot read, and they cost more and are not safe for trimming.
+[Unsafe twins and the runtime fallback](unsafe.md) covers them.
+
+## The five sample apps
+
+Every page in this section uses the same sample apps, so a type you meet on one page is the same type on the next.
+
+| App | What it models |
+| --- | --- |
+| To-do list | A list with a filter box, a count of unfinished items and commands to add and finish an item. |
+| GitHub issues | An issue board with repositories, issues, comments and users. |
+| Cloud storage | A storage browser with buckets, objects, uploads and a connection state. |
+| School | A gradebook with students, courses, enrolments, assignments and grades. |
+| Bank | Accounts, payees and transfers with validation. |
+
+The apps live in the [Common folder](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/tree/main/src/examples/Documentation/Common)
+of the examples. They talk to in-memory services, so no example needs a network or a database.
+
+## Find a topic
+
+| Page | What you can do |
+| --- | --- |
+| [Observing](observing.md) | Watch one to sixteen properties with `WhenChanged`, `WhenChanging`, `WhenAnyValue`, `WhenAny` and `WhenAnyObservable`. |
+| [Bindings](bindings.md) | Connect properties one way and two ways, bind to a command or an interaction, and handle errors. |
+| [Converters](converters.md) | Use the built-in converters for numbers, dates, booleans, strings and nullable values. |
+| [Custom converters](custom-converters.md) | Write and register your own converter and choose a fallback. |
+| [Mechanisms](mechanisms.md) | See how a type announces a change and how the generator picks a way to listen. |
+| [Views](views.md) | Use `IViewFor<T>`, the view locator and view mappings. |
+| [Threading and platforms](threading.md) | Write on the owning thread, choose a scheduler, and use the WPF, WinForms, MAUI and Avalonia packages. |
+| [Setup](setup.md) | Start the builder, choose the System.Reactive package, publish with Native AOT and read the analyzer's diagnostics. |
+| [Unsafe twins and the runtime fallback](unsafe.md) | Bind a call site that the generator cannot read. |
+| [API reference](api.md) | Look up every public type and member with its parameters and return value. |
+
+## Run the examples
+
+The [documentation examples](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/tree/main/src/examples/Documentation)
+live in folders named for their page. Each page links to its folder. Each folder is a small program that
+prints what the page shows. The page examples reference the library source projects, including the generator that writes the binding code.
+
+The code on a page is an excerpt of the real example. Setup and helper code stay in the project when a page does not need them.
+An example prints its results with `Console.WriteLine`, and the page shows those lines in a block under the code.
+
+From the repository's `src` folder, run the example for this page:
+
+```bash
+dotnet run --project examples/Documentation/Pages/index/index.csproj -c Release
+```
+
+## API reference
+
+| Member | What it does | Type and values | Notes |
+| --- | --- | --- | --- |
+| [`WhenChanged`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenChanged.WideArity.cs) | Watches a property. It delivers the current value when you subscribe, then the new value after each change. | Extension method on `TObj : class`. Takes `Expression<Func<TObj, T1>> property1`. Returns [`IObservable<T1>`](https://learn.microsoft.com/dotnet/api/system.iobservable-1). Other forms take up to 16 properties and return `PropertyValues<T1..T16>`. | The lambda has to be written inline at the call. A call the generator cannot read throws `InvalidOperationException` when it runs. The [Observing](observing.md) page covers the other forms. |
+| [`WhenChangedUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenChanged.WideArity.Unsafe.cs) | Watches a property by reflection, for a lambda the generator cannot read. | Extension method on `TObj : class`. Takes `Expression<Func<TObj, T1>> property1`. Returns `IObservable<T1>`. Other forms take up to 16 properties. | Carries `RequiresUnreferencedCode`. Throws `ArgumentNullException` for a null object or lambda. |
+| [`BindOneWay`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.Binding.cs) | Copies a source property to a target property, then again after each change. It writes on the thread that owns the target. | Extension method on `TSource : class`. Takes `TTarget : class target`, a source lambda and a target lambda. The target lambda may be a property path. Add a `Func<TSourceProp, TTargetProp> conversionFunc` when the two types differ. Returns [`IDisposable`](https://learn.microsoft.com/dotnet/api/system.idisposable). | Dispose the result to stop the binding. A call the generator cannot read throws `InvalidOperationException` when it runs. Forms that take an `ISequencer` scheduler or an `IBindingTypeConverter` are declared in [`ReactiveSchedulerExtensions`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveSchedulerExtensions.cs). The [Bindings](bindings.md) page covers them. |
+| [`BindOneWayUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.Binding.Unsafe.cs) | Binds one way by reflection, for a lambda the generator cannot read. | Extension method on `TSource : class`. Takes the same arguments as `BindOneWay`, with or without a `conversionFunc`. Returns `IDisposable`. | Carries `RequiresUnreferencedCode`. [Unsafe twins and the runtime fallback](unsafe.md) covers it. |
diff --git a/docs/documentation/binding/mechanisms.md b/docs/documentation/binding/mechanisms.md
new file mode 100644
index 00000000..7522d288
--- /dev/null
+++ b/docs/documentation/binding/mechanisms.md
@@ -0,0 +1,1519 @@
+---
+Order: 6
+---
+# Mechanisms
+
+[Run the complete page example](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/mechanisms/mechanisms.csproj).
+
+A property cannot tell you when it changes. The class that owns it has to announce the change, and classes announce in different ways. One class raises `PropertyChanged`. Another raises an event named after the property. A third raises nothing at all. When you observe or bind a property, the library must choose a way to listen for each of them.
+
+A **mechanism** is one way of receiving those announcements. A **provider** is a class that implements `ICreatesObservableForProperty`, and each provider supplies one mechanism. A provider reports an **affinity**, which is a score for a type and a property. Zero means the provider cannot observe that property, and the highest score wins. This page shows how the winner is chosen, how to add a provider for your own type, how command binders follow the same rules, and what the observable types deliver. [Observing](observing.md) explains observables and subscriptions, and the [index](index.md) explains the source generator.
+
+Start with the common case. When a class raises `PropertyChanged`, the generated code listens to that event, so you receive the current value and then each change. This excerpt observes the done flag of a to-do item and then sets it.
+
+```csharp
+using (item.WhenChanged(x => x.IsDone).Subscribe(Console.WriteLine))
+{
+    item.IsDone = true;
+}
+```
+
+```text
+False
+True
+```
+
+A plain class raises nothing, so no mechanism can tell you about a later edit. This excerpt sets the size of a stored object after subscribing. The edit never reaches the subscriber, which is why a class you observe should announce its changes.
+
+```csharp
+using (stored.WhenChanged(x => x.Size).Subscribe(Console.WriteLine))
+{
+    stored.Size = ResizedBytes;
+}
+```
+
+```text
+2411724
+```
+
+## Observe a type that announces changes its own way
+
+A `StorageConnection` raises a plain `StateChanged` event and implements no notification interface. No built-in provider can observe it, so you write one.
+
+**1. Write the provider.** `GetAffinityForObject` bids `BindingAffinity.WinFormsEvent` (8) for the `State` property of a `StorageConnection` and 0 for everything else. `GetNotificationForProperty` returns the stream of changes. `Signal.FromEventPattern` turns the event into a stream, and `Select` turns each event into an `ObservedChange` that names the sender, the expression and the current value. A before-change request or a different sender gets `ImmutableNeverSignal`, a stream that never delivers. See [creation factories](../primitives/creation-factories.md) and the [Primitives types](../primitives/types.md).
+
+```csharp
+public sealed class StorageConnectionObservableForProperty : ICreatesObservableForProperty
+{
+    public int GetAffinityForObject(Type type, string propertyName, bool beforeChanged) =>
+        !beforeChanged && type == typeof(StorageConnection) && propertyName == nameof(StorageConnection.State)
+            ? BindingAffinity.WinFormsEvent
+            : 0;
+
+    public IObservable<IObservedChange<object, object?>> GetNotificationForProperty(
+        object sender,
+        Expression expression,
+        string propertyName,
+        bool beforeChanged,
+        bool suppressWarnings)
+    {
+        if (beforeChanged || sender is not StorageConnection connection)
+        {
+            return ImmutableNeverSignal<IObservedChange<object, object?>>.Instance;
+        }
+
+        Console.WriteLine("The connection state is observed by the StateChanged provider");
+
+        return Signal.FromEventPattern(handler => connection.StateChanged += handler, handler => connection.StateChanged -= handler)
+            .Select(_ => new ObservedChange<object, object?>(connection, expression, connection.State));
+    }
+}
+```
+
+**2. Register it.** `WithRegistration` adds the provider to the service locator. `ObservationAffinityChecker.Refresh()` clears the cached scores so the next observation reads the new registration. `HasHigherAffinityPlugin` asks whether a registered provider outranks a given score, here the fallback score.
+
+```csharp
+var outranksBefore = ObservationAffinityChecker.HasHigherAffinityPlugin(typeof(StorageConnection), StatePropertyName, BindingAffinity.Fallback, false);
+
+Console.WriteLine($"Provider outranks the fallback before registering: {outranksBefore}");
+
+IReactiveUIBindingBuilder builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+
+_ = builder
+    .WithCoreServices()
+    .WithRegistration(resolver => resolver.RegisterConstant<ICreatesObservableForProperty>(provider))
+    .BuildApp();
+
+ObservationAffinityChecker.Refresh();
+
+Console.WriteLine($"Provider is registered: {AppLocator.Current.GetServices<ICreatesObservableForProperty>().Contains(provider)}");
+var outranksAfter = ObservationAffinityChecker.HasHigherAffinityPlugin(typeof(StorageConnection), StatePropertyName, BindingAffinity.Fallback, false);
+
+Console.WriteLine($"Provider outranks the fallback after registering: {outranksAfter}");
+```
+
+```text
+Provider outranks the fallback before registering: False
+Provider is registered: True
+Provider outranks the fallback after registering: True
+```
+
+**3. Observe the property.** `WhenChanged` works as it does for any other type. The provider serves the call. The first value is the current state, and each later value comes from the event.
+
+```csharp
+using (browser.Connection.WhenChanged(x => x.State).Subscribe(static state => Console.WriteLine(state)))
+{
+    storage.Disconnect();
+    storage.Connection.State = ConnectionState.Connected;
+}
+```
+
+```text
+The connection state is observed by the StateChanged provider
+Connected
+Disconnected
+Connected
+```
+
+## How affinity picks the winner
+
+Every mechanism uses the same scale. `BindingAffinity` holds the scores.
+
+| Score | Value | Meaning |
+| --- | --- | --- |
+| `Fallback` | 1 | The POCO provider, for a class that raises nothing. |
+| `DefaultInternalTypeConverter` | 2 | The built-in value and string converters. |
+| `DefaultEvent` | 3 | A conventional default event of a type. |
+| `WpfDependencyObject` | 4 | A WPF dependency property. |
+| `EventEnabledControl` | 4 | A command binding through an event on a control. |
+| `Explicit` | 5 | An interface such as `INotifyPropertyChanged`, or a named event. |
+| `WinUiDependencyObject` | 6 | A WinUI dependency property. |
+| `WinFormsEvent` | 8 | A WinForms event-based property observation. |
+| `ExactType` | 10 | A strong match, such as an `IReactiveObject`. |
+| `Kvo` | 15 | Apple key-value observing on an `NSObject`. |
+
+The source generator picks the best mechanism it can see when your project builds. A provider you register at run time replaces that choice only when its score is strictly higher. A tie keeps the generated mechanism. Among registered providers, the highest score wins and the first registered wins a tie. `ObservationAffinityChecker` reads the registrations on first use and caches the best score for each type, property and timing. Call `Refresh()` after you register a provider. The [threading](threading.md) page covers the platform mechanisms.
+
+This excerpt scores three properties and names the provider that wins each. The `PropertyChanged` provider bids 5 for a `TodoItem` and 0 for a plain `StorageObject`. The fallback provider bids 1 for both. `TodoPropertyObservableForProperty` is a provider in the example project that bids a chosen score for one `TodoItem` property.
+
+```csharp
+Console.WriteLine($"PropertyChanged provider, to-do item: {new INPCObservableForProperty().GetAffinityForObject(typeof(TodoItem), nameof(TodoItem.IsDone))}");
+Console.WriteLine($"PropertyChanged provider, stored object: {new INPCObservableForProperty().GetAffinityForObject(typeof(StorageObject), nameof(StorageObject.Size))}");
+Console.WriteLine($"Fallback provider, stored object: {new POCOObservableForProperty().GetAffinityForObject(typeof(StorageObject), nameof(StorageObject.Size))}");
+
+Console.WriteLine($"IsDone is observed by {SelectHighestAffinity(typeof(TodoItem), nameof(TodoItem.IsDone))?.GetType().Name}");
+Console.WriteLine($"Size is observed by {SelectHighestAffinity(typeof(StorageObject), nameof(StorageObject.Size))?.GetType().Name}");
+Console.WriteLine($"Title is observed by {SelectHighestAffinity(typeof(TodoItem), TitlePropertyName)?.GetType().Name}");
+```
+
+```text
+PropertyChanged provider, to-do item: 5
+PropertyChanged provider, stored object: 0
+Fallback provider, stored object: 1
+IsDone is observed by INPCObservableForProperty
+Size is observed by POCOObservableForProperty
+Title is observed by TodoPropertyObservableForProperty
+```
+
+The next excerpt shows a tie and an outranking bid. One provider bids `Explicit` for `Notes`, the same score as the `PropertyChanged` mechanism. Another bids one more for `Title`. The tied provider is never used, and the outranking one is.
+
+```csharp
+using (item.WhenChanged(x => x.Notes).Subscribe(Console.WriteLine))
+using (item.WhenChanged(x => x.Title).Subscribe(Console.WriteLine))
+{
+    item.Notes = EditedNotes;
+    item.Title = EditedTitle;
+}
+```
+
+```text
+Bring the old plate as well.
+Title is observed by the provider that bids 6
+Renew car registration by post
+Bring the insurance certificate and the old plate.
+Renew car registration online
+```
+
+This excerpt compares every score with a provider that bids `Explicit` for `Notes`. The provider outranks each score below its bid. It loses to its own score and to every score above it.
+
+```csharp
+(string Name, int Score)[] scores =
+[
+    (nameof(BindingAffinity.Fallback), BindingAffinity.Fallback),
+    (nameof(BindingAffinity.DefaultInternalTypeConverter), BindingAffinity.DefaultInternalTypeConverter),
+    (nameof(BindingAffinity.DefaultEvent), BindingAffinity.DefaultEvent),
+    (nameof(BindingAffinity.WpfDependencyObject), BindingAffinity.WpfDependencyObject),
+    (nameof(BindingAffinity.EventEnabledControl), BindingAffinity.EventEnabledControl),
+    (nameof(BindingAffinity.Explicit), BindingAffinity.Explicit),
+    (nameof(BindingAffinity.WinUiDependencyObject), BindingAffinity.WinUiDependencyObject),
+    (nameof(BindingAffinity.WinFormsEvent), BindingAffinity.WinFormsEvent),
+    (nameof(BindingAffinity.ExactType), BindingAffinity.ExactType),
+    (nameof(BindingAffinity.Kvo), BindingAffinity.Kvo),
+];
+
+foreach (var (name, score) in scores)
+{
+    var outranked = ObservationAffinityChecker.HasHigherAffinityPlugin(typeof(TodoItem), NotesPropertyName, score, false);
+
+    Console.WriteLine($"{name} ({score}): provider outranks it = {outranked}");
+}
+```
+
+```text
+Fallback (1): provider outranks it = True
+DefaultInternalTypeConverter (2): provider outranks it = True
+DefaultEvent (3): provider outranks it = True
+WpfDependencyObject (4): provider outranks it = True
+EventEnabledControl (4): provider outranks it = True
+Explicit (5): provider outranks it = False
+WinUiDependencyObject (6): provider outranks it = False
+WinFormsEvent (8): provider outranks it = False
+ExactType (10): provider outranks it = False
+Kvo (15): provider outranks it = False
+```
+
+## The built-in providers
+
+`INPCObservableForProperty` bids `Explicit` (5) for any type that implements `INotifyPropertyChanged`. It does not look at the property name. For before-change observation it needs `INotifyPropertyChanging` instead. A type without that interface, such as `TodoItem`, gets 0 for before-change requests.
+
+The excerpt asks the provider about a `TodoItem` and listens to it directly. Editing `Notes` raises `PropertyChanged` for another property, so the stream ignores it. Only the `Title` edit arrives, and the change names the item as its sender.
+
+```csharp
+INPCObservableForProperty provider = new();
+Expression<Func<TodoItem, string>> property = x => x.Title;
+
+Console.WriteLine($"Affinity: {provider.GetAffinityForObject(typeof(TodoItem), TitlePropertyName)}");
+Console.WriteLine($"Affinity after a change: {provider.GetAffinityForObject(typeof(TodoItem), TitlePropertyName, false)}");
+
+// TodoItem does not implement INotifyPropertyChanging, so the provider bids nothing for before-change observation.
+Console.WriteLine($"Affinity before a change: {provider.GetAffinityForObject(typeof(TodoItem), TitlePropertyName, true)}");
+
+List<IObservedChange<object, object?>> changes = [];
+using (provider.GetNotificationForProperty(item, property.Body, TitlePropertyName).Subscribe(changes.Add))
+{
+    item.Notes = EditedNotes;
+    item.Title = RetitledByPost;
+}
+
+Console.WriteLine($"Notifications: {changes.Count}");
+Console.WriteLine($"Sender is the item: {ReferenceEquals(item, changes[0].Sender)}");
+Console.WriteLine($"Property: {changes[0].GetPropertyName()}");
+```
+
+```text
+Affinity: 5
+Affinity after a change: 5
+Affinity before a change: 0
+Notifications: 1
+Sender is the item: True
+Property: Title
+```
+
+A plain class does not implement the interface, so this provider bids 0 and reports nothing. The excerpt shows why the fallback provider, not this one, serves such a class.
+
+```csharp
+INPCObservableForProperty provider = new();
+Expression<Func<StorageObject, long>> property = x => x.Size;
+
+Console.WriteLine($"Affinity: {provider.GetAffinityForObject(typeof(StorageObject), SizePropertyName)}");
+
+List<IObservedChange<object, object?>> changes = [];
+using (provider.GetNotificationForProperty(stored, property.Body, SizePropertyName).Subscribe(changes.Add))
+{
+    stored.Size = ResizedBytes;
+}
+
+Console.WriteLine($"Notifications: {changes.Count}");
+```
+
+```text
+Affinity: 0
+Notifications: 0
+```
+
+A MAUI control is a `BindableObject`, which implements `INotifyPropertyChanged`. `WhenChanged` delivers the text of an `Entry` at subscription and after each edit.
+
+```csharp
+TodoView view = new();
+
+using (view.NewTitleTextBox.WhenChanged(x => x.Text).Subscribe(static text => Console.WriteLine(text ?? "(none)")))
+{
+    view.NewTitleTextBox.Text = TypedTitle;
+}
+```
+
+```text
+(none)
+Call the plumber
+```
+
+The next excerpt asks both built-in providers about an `Entry`. The `PropertyChanged` provider bids 5 and the fallback provider bids 1, so the `PropertyChanged` mechanism wins for a MAUI control.
+
+```csharp
+INPCObservableForProperty propertyChanged = new();
+POCOObservableForProperty fallback = new();
+
+Console.WriteLine($"PropertyChanged provider: {propertyChanged.GetAffinityForObject(typeof(Entry), TextPropertyName)}");
+Console.WriteLine($"Fallback provider: {fallback.GetAffinityForObject(typeof(Entry), TextPropertyName)}");
+```
+
+```text
+PropertyChanged provider: 5
+Fallback provider: 1
+```
+
+`POCOObservableForProperty` bids `Fallback` (1) for every type and property. Its stream delivers one notification when observation starts and then stays silent. It writes a debug message the first time it observes a type and property, unless the caller suppresses warnings. The last argument of `GetNotificationForProperty` is `suppressWarnings`.
+
+```csharp
+POCOObservableForProperty provider = new();
+Expression<Func<StorageObject, long>> property = x => x.Size;
+
+Console.WriteLine($"Affinity for a stored object: {provider.GetAffinityForObject(typeof(StorageObject), SizePropertyName)}");
+Console.WriteLine($"Affinity for a to-do item: {provider.GetAffinityForObject(typeof(TodoItem), TitlePropertyName)}");
+
+List<IObservedChange<object, object?>> changes = [];
+using (provider.GetNotificationForProperty(stored, property.Body, SizePropertyName, false, true).Subscribe(changes.Add))
+{
+    Console.WriteLine($"Notifications at the start: {changes.Count}");
+
+    stored.Size = ResizedBytes;
+}
+
+Console.WriteLine($"Notifications after the change: {changes.Count}");
+Console.WriteLine($"Sender is the stored object: {ReferenceEquals(stored, changes[0].Sender)}");
+Console.WriteLine($"Property: {changes[0].GetPropertyName()}");
+```
+
+```text
+Affinity for a stored object: 1
+Affinity for a to-do item: 1
+Notifications at the start: 1
+Notifications after the change: 1
+Sender is the stored object: True
+Property: Size
+```
+
+The fallback does not look at timing, so it answers a before-change request as well as an after-change one. Its score is the lowest positive one, so any other provider outranks it. The excerpt asks for both timings.
+
+```csharp
+POCOObservableForProperty provider = new();
+
+Console.WriteLine($"Affinity after a change: {provider.GetAffinityForObject(typeof(StorageObject), SizePropertyName, false)}");
+Console.WriteLine($"Affinity before a change: {provider.GetAffinityForObject(typeof(StorageObject), SizePropertyName, true)}");
+```
+
+```text
+Affinity after a change: 1
+Affinity before a change: 1
+```
+
+You get both built-in providers when you call `WithCoreServices` on the builder, so an application that registers no provider of its own can observe any type. The loop lists the registered providers, `INPCObservableForProperty` first.
+
+```csharp
+IReactiveUIBindingBuilder builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+
+_ = builder.WithCoreServices().BuildApp();
+
+foreach (var provider in AppLocator.Current.GetServices<ICreatesObservableForProperty>())
+{
+    Console.WriteLine(provider.GetType().Name);
+}
+```
+
+```text
+INPCObservableForProperty
+POCOObservableForProperty
+```
+
+A path can pass through a notifying object to a plain one. This excerpt observes the selected object of a view model. The view model raises `PropertyChanged` for the selection, and the plain `Size` is read on each delivery. The first `Size` edit raises nothing, so it prints nothing.
+
+```csharp
+browser.SelectedObject = first;
+
+using (browser.WhenChanged(x => x.SelectedObject!).Subscribe(static selected => Console.WriteLine(selected.Size)))
+{
+    first.Size = ResizedBytes;
+    browser.SelectedObject = second;
+}
+```
+
+```text
+2411724
+5562368
+```
+
+A class that implements `INotifyPropertyChanging` lets you read a property before an edit replaces it. `DraftTodo` implements it, so `WhenChanging` delivers the title on subscription and before the edit. Editing `Notes` delivers nothing.
+
+```csharp
+DraftTodo draft = new() { Title = RegistrationTitle };
+
+using (draft.WhenChanging(x => x.Title).Subscribe(Console.WriteLine))
+{
+    draft.Title = RenamedTitle;
+    draft.Notes = RegistrationNotes;
+}
+```
+
+```text
+Renew car registration
+Renew car registration
+```
+
+The provider itself bids 5 for a before-change request on a `DraftTodo`. Its stream delivers the notification while the sender holds the old title.
+
+```csharp
+DraftTodo draft = new() { Title = RegistrationTitle };
+INPCObservableForProperty provider = new();
+Expression<Func<DraftTodo, string>> property = x => x.Title;
+
+Console.WriteLine($"Affinity before a change: {provider.GetAffinityForObject(typeof(DraftTodo), TitlePropertyName, true)}");
+
+List<string> titlesBefore = [];
+using (provider.GetNotificationForProperty(draft, property.Body, TitlePropertyName, true).Subscribe(change => titlesBefore.Add(((DraftTodo)change.Sender).Title)))
+{
+    draft.Title = RenamedTitle;
+}
+
+Console.WriteLine($"Titles read before the change: {string.Join(", ", titlesBefore)}");
+```
+
+```text
+Affinity before a change: 5
+Titles read before the change: Renew car registration
+```
+
+## Call a provider directly
+
+You can call a provider yourself. `CreatesObservableForPropertyMixins` adds overloads that default `beforeChanged` and `suppressWarnings` to `false`, so the short calls below ask about after-change observation. The last argument of the full `GetNotificationForProperty` call, `suppressWarnings`, silences the message the fallback provider writes. The provider reports its bid for the `State` property (8), for `Endpoint` (0) and for a before-change request (0). Its stream delivers one notification for each event and nothing on subscription.
+
+```csharp
+Expression<Func<StorageConnection, ConnectionState>> property = x => x.State;
+
+Console.WriteLine($"Affinity for State: {provider.GetAffinityForObject(typeof(StorageConnection), StatePropertyName)}");
+Console.WriteLine($"Affinity for Endpoint: {provider.GetAffinityForObject(typeof(StorageConnection), nameof(StorageConnection.Endpoint))}");
+Console.WriteLine($"Affinity for State before a change: {provider.GetAffinityForObject(typeof(StorageConnection), StatePropertyName, true)}");
+
+List<IObservedChange<object, object?>> after = [];
+using (provider.GetNotificationForProperty(connection, property.Body, StatePropertyName).Subscribe(after.Add))
+{
+    connection.State = ConnectionState.Connecting;
+    connection.State = ConnectionState.Connected;
+}
+
+Console.WriteLine($"Notifications: {after.Count}");
+Console.WriteLine($"Sender is the connection: {ReferenceEquals(connection, after[0].Sender)}");
+Console.WriteLine($"First value: {after[0].Value}");
+Console.WriteLine($"Second value: {after[1].Value}");
+
+List<IObservedChange<object, object?>> before = [];
+using (provider.GetNotificationForProperty(connection, property.Body, StatePropertyName, true).Subscribe(before.Add))
+{
+    connection.State = ConnectionState.Connecting;
+    connection.State = ConnectionState.Connected;
+}
+
+Console.WriteLine($"Notifications before a change: {before.Count}");
+```
+
+```text
+Affinity for State: 8
+Affinity for Endpoint: 0
+Affinity for State before a change: 0
+The connection state is observed by the StateChanged provider
+Notifications: 2
+Sender is the connection: True
+First value: Connecting
+Second value: Connected
+Notifications before a change: 0
+```
+
+The full interface call takes all five arguments. This excerpt picks the registered provider with the highest bid, as the run-time engine does, and calls it through `ICreatesObservableForProperty`. The last two arguments are `beforeChanged` and `suppressWarnings`. This provider delivers the two changes and nothing on subscription.
+
+```csharp
+var registered = AppLocator.Current
+    .GetServices<ICreatesObservableForProperty>()
+    .MaxBy(static candidate => candidate.GetAffinityForObject(typeof(StorageConnection), StatePropertyName, false))!;
+Expression<Func<StorageConnection, ConnectionState>> property = x => x.State;
+
+Console.WriteLine($"Affinity for State: {registered.GetAffinityForObject(typeof(StorageConnection), StatePropertyName, false)}");
+
+using (registered.GetNotificationForProperty(connection, property.Body, StatePropertyName, false, true).Subscribe(static change => Console.WriteLine(change.Value)))
+{
+    connection.State = ConnectionState.Connecting;
+    connection.State = ConnectionState.Connected;
+}
+```
+
+```text
+Affinity for State: 8
+The connection state is observed by the StateChanged provider
+Connecting
+Connected
+```
+
+## How generated code consults providers
+
+The `ObservableForProperty` extension method observes a property by asking the registered providers directly. It picks the provider with the highest affinity for the runtime type, and it throws `InvalidOperationException` when no provider bids above zero. It has overloads that take a property name or a lambda, and optional `beforeChange`, `skipInitial` and `isDistinct` arguments. It reads members by reflection, so it is not safe for trimming. The excerpt observes the connection state through the registered provider and prints every state the provider delivers.
+
+```csharp
+using (browser.Connection.ObservableForProperty(x => x.State, false).Subscribe(static change => Console.WriteLine(change.Value)))
+{
+    storage.Disconnect();
+    await browser.ConnectAsync().ConfigureAwait(false);
+}
+```
+
+```text
+The connection state is observed by the StateChanged provider
+Connected
+Disconnected
+Connecting
+Connected
+```
+
+Generated code makes a choice for each link of a property path. It asks `FindHigherAffinityPlugin` for a registered provider that outranks the score of the mechanism it was generated from. `HasHigherAffinityPlugin` gives the same answer as a `bool`. The excerpt asks at four generated scores. The provider outranks the fallback, and it is the provider that outranks the `PropertyChanged` score. An equal score and a higher score both keep the generated mechanism.
+
+```csharp
+var connectionType = typeof(StorageConnection);
+
+var outranksFallback = ObservationAffinityChecker.HasHigherAffinityPlugin(connectionType, StatePropertyName, BindingAffinity.Fallback, false);
+var winnerOverPropertyChanged = ObservationAffinityChecker.FindHigherAffinityPlugin(connectionType, StatePropertyName, BindingAffinity.Explicit, false);
+
+Console.WriteLine($"Outranks the fallback: {outranksFallback}");
+Console.WriteLine($"Outranks the PropertyChanged provider: {winnerOverPropertyChanged?.GetType().Name}");
+
+// A tie goes to the generated mechanism, and so does a higher generated score.
+var outranksEqual = ObservationAffinityChecker.HasHigherAffinityPlugin(connectionType, StatePropertyName, BindingAffinity.WinFormsEvent, false);
+var winnerOverHigher = ObservationAffinityChecker.FindHigherAffinityPlugin(connectionType, StatePropertyName, BindingAffinity.Kvo, false);
+
+Console.WriteLine($"Outranks an equal score: {outranksEqual}");
+Console.WriteLine($"Nothing outranks a higher score: {winnerOverHigher is null}");
+
+// The provider answers for one property and only after a change.
+var forEndpoint = ObservationAffinityChecker.FindHigherAffinityPlugin(connectionType, nameof(StorageConnection.Endpoint), BindingAffinity.Fallback, false);
+var beforeChange = ObservationAffinityChecker.FindHigherAffinityPlugin(connectionType, StatePropertyName, BindingAffinity.Fallback, true);
+
+Console.WriteLine($"Nothing answers for Endpoint: {forEndpoint is null}");
+Console.WriteLine($"Nothing answers before a change: {beforeChange is null}");
+```
+
+```text
+Outranks the fallback: True
+Outranks the PropertyChanged provider: StorageConnectionObservableForProperty
+Outranks an equal score: False
+Nothing outranks a higher score: True
+Nothing answers for Endpoint: True
+Nothing answers before a change: True
+```
+
+`PluginObservationSource.Choose` applies that rule to one link. You give it the source object, the expression, the property name, the before-change flag, the score of the generated mechanism, a getter and the generated observation. It returns the generated observation when no provider outranks the score.
+
+```csharp
+Expression<Func<TodoItem, bool>> isDone = x => x.IsDone;
+PropertyObservable<bool> generated = new(item, nameof(TodoItem.IsDone), static source => ((TodoItem)source).IsDone, true);
+
+var chosen = PluginObservationSource.Choose(
+    item,
+    isDone.Body,
+    nameof(TodoItem.IsDone),
+    false,
+    BindingAffinity.Explicit,
+    static source => ((TodoItem)source).IsDone,
+    generated);
+
+Console.WriteLine($"The generated observation is kept: {ReferenceEquals(generated, chosen)}");
+```
+
+```text
+The generated observation is kept: True
+```
+
+A provider that only ties the generated score does not take over either. Here the generated observation is an `EventObservable<ConnectionState>`, and the score comes from the provider's own bid.
+
+```csharp
+StorageConnection connection = new() { Endpoint = StorageEndpoint };
+Expression<Func<StorageConnection, ConnectionState>> state = x => x.State;
+EventObservable<ConnectionState> generated = new(
+    handler => connection.StateChanged += handler,
+    handler => connection.StateChanged -= handler,
+    () => connection.State,
+    true);
+
+var chosen = PluginObservationSource.Choose(
+    connection,
+    state.Body,
+    StateName,
+    false,
+    provider.GetAffinityForObject(typeof(StorageConnection), StateName, false),
+    static source => ((StorageConnection)source).State,
+    generated);
+
+Console.WriteLine($"The generated observation is kept: {ReferenceEquals(generated, chosen)}");
+```
+
+```text
+The generated observation is kept: True
+```
+
+A low generated score hands the observation to the provider, and a high one keeps the generated observation. `UnchangingPropertyObservable<T>` stands in for the generated observation here. Subscribing to the provider's observable prints the provider's message and then the states.
+
+```csharp
+Expression<Func<StorageConnection, ConnectionState>> property = x => x.State;
+UnchangingPropertyObservable<ConnectionState> generated = new(connection.State);
+
+var lowGenerated = PluginObservationSource.Choose(
+    connection,
+    property.Body,
+    StatePropertyName,
+    false,
+    BindingAffinity.Fallback,
+    static source => ((StorageConnection)source).State,
+    generated);
+var highGenerated = PluginObservationSource.Choose(
+    connection,
+    property.Body,
+    StatePropertyName,
+    false,
+    BindingAffinity.Kvo,
+    static source => ((StorageConnection)source).State,
+    generated);
+
+Console.WriteLine($"A low score hands over to the provider: {lowGenerated is PluginPropertyObservable<ConnectionState>}");
+Console.WriteLine($"A high score keeps the generated observation: {ReferenceEquals(generated, highGenerated)}");
+
+using (lowGenerated.Subscribe(static state => Console.WriteLine(state)))
+{
+    connection.State = ConnectionState.Disconnected;
+    connection.State = ConnectionState.Connected;
+}
+```
+
+```text
+A low score hands over to the provider: True
+A high score keeps the generated observation: True
+The connection state is observed by the StateChanged provider
+Connected
+Disconnected
+Connected
+```
+
+When a provider does win, `Choose` returns a `PluginPropertyObservable<T>`. The provider says when the property changed, and the getter reads the value, so the value never comes from the notification. The observable delivers the current value on subscription and again after each notification. The last two constructor arguments are the before-change flag and the flag that drops repeated values.
+
+```csharp
+Expression<Func<StorageConnection, ConnectionState>> property = x => x.State;
+PluginPropertyObservable<ConnectionState> observable = new(
+    provider,
+    connection,
+    property.Body,
+    StatePropertyName,
+    static source => ((StorageConnection)source).State,
+    false,
+    true);
+
+using (observable.Subscribe(static state => Console.WriteLine(state)))
+{
+    connection.State = ConnectionState.Disconnected;
+    connection.State = ConnectionState.Connected;
+}
+```
+
+```text
+The connection state is observed by the StateChanged provider
+Connected
+Disconnected
+Connected
+```
+
+`Subscribe` also takes an observer object. `Witness.Create<T>` builds one from a lambda. Every observable on this page takes one the same way.
+
+```csharp
+Expression<Func<StorageConnection, ConnectionState>> property = x => x.State;
+PluginPropertyObservable<ConnectionState> observable = new(
+    provider,
+    connection,
+    property.Body,
+    StatePropertyName,
+    static source => ((StorageConnection)source).State,
+    false,
+    true);
+var observer = Witness.Create<ConnectionState>(static state => Console.WriteLine(state));
+
+using (observable.Subscribe(observer))
+{
+    connection.State = ConnectionState.Disconnected;
+    connection.State = ConnectionState.Connected;
+}
+```
+
+```text
+The connection state is observed by the StateChanged provider
+Connected
+Disconnected
+Connected
+```
+
+`ObservableForPropertySink<TSender, TValue>` wraps a provider's notifications and reads the value on each one. Its last two arguments skip the initial value and drop repeated values.
+
+```csharp
+Expression<Func<StorageConnection, ConnectionState>> property = x => x.State;
+var notifications = provider.GetNotificationForProperty(connection, property.Body, StatePropertyName);
+ObservableForPropertySink<StorageConnection, ConnectionState> sink = new(
+    connection,
+    property.Body,
+    notifications,
+    () => connection.State,
+    false,
+    true);
+
+using (sink.Subscribe(static change => Console.WriteLine(change.Value)))
+{
+    connection.State = ConnectionState.Disconnected;
+    connection.State = ConnectionState.Connected;
+}
+```
+
+```text
+The connection state is observed by the StateChanged provider
+Connected
+Disconnected
+Connected
+```
+
+The sink also accepts an observer object. Use this form when you have an `IObserver<T>` in hand, as the excerpt does. The values it receives are the same.
+
+```csharp
+Expression<Func<StorageConnection, ConnectionState>> property = x => x.State;
+var notifications = provider.GetNotificationForProperty(connection, property.Body, StatePropertyName);
+ObservableForPropertySink<StorageConnection, ConnectionState> sink = new(
+    connection,
+    property.Body,
+    notifications,
+    () => connection.State,
+    false,
+    true);
+var observer = Witness.Create<IObservedChange<StorageConnection, ConnectionState>>(static change => Console.WriteLine(change.Value));
+
+using (sink.Subscribe(observer))
+{
+    connection.State = ConnectionState.Disconnected;
+    connection.State = ConnectionState.Connected;
+}
+```
+
+```text
+The connection state is observed by the StateChanged provider
+Connected
+Disconnected
+Connected
+```
+
+`ExpressionChainSink<TSender, TValue>` observes a whole path such as `x.Connection.State`. It observes each link on the value the previous link produced, and it attaches the deeper links again when a value in the middle changes. It delivers nothing while a value in the middle is null, and every change it delivers names the root object as its sender. `ExpressionChainParameters<TSender>` bundles the arguments. The chain engine reads members by reflection, so it is not safe for trimming.
+
+```csharp
+Expression<Func<StorageBrowserViewModel, ConnectionState>> property = x => x.Connection.State;
+Expression[] links = [.. Reflection.Rewrite(property.Body).GetExpressionChain()];
+ExpressionChainParameters<StorageBrowserViewModel> parameters = new(browser, property.Body, links, false, false, true, true);
+ExpressionChainSink<StorageBrowserViewModel, ConnectionState> sink = new(
+    parameters.Source,
+    parameters.Expression,
+    parameters.Links,
+    parameters.BeforeChange,
+    parameters.SkipInitial,
+    parameters.IsDistinct,
+    parameters.SuppressWarnings);
+
+using (sink.Subscribe(change => Console.WriteLine($"{change.Value}, sent by the browser: {ReferenceEquals(browser, change.Sender)}")))
+{
+    browser.Connection.State = ConnectionState.Disconnected;
+    browser.Connection.State = ConnectionState.Connected;
+}
+```
+
+```text
+The connection state is observed by the StateChanged provider
+Connected, sent by the browser: True
+Disconnected, sent by the browser: True
+Connected, sent by the browser: True
+```
+
+The sink constructor also takes the values directly, so you do not need the parameters record. This excerpt passes them in one call and reads the changes through an observer object. It matters when you write your own wiring, because the sink needs only the source, the expression and the links.
+
+```csharp
+Expression<Func<StorageBrowserViewModel, ConnectionState>> property = x => x.Connection.State;
+Expression[] links = [.. Reflection.Rewrite(property.Body).GetExpressionChain()];
+ExpressionChainSink<StorageBrowserViewModel, ConnectionState> sink = new(browser, property.Body, links, false, false, true, true);
+var observer = Witness.Create<IObservedChange<StorageBrowserViewModel, ConnectionState>>(static change => Console.WriteLine(change.Value));
+
+using (sink.Subscribe(observer))
+{
+    browser.Connection.State = ConnectionState.Disconnected;
+    browser.Connection.State = ConnectionState.Connected;
+}
+```
+
+```text
+The connection state is observed by the StateChanged provider
+Connected
+Disconnected
+Connected
+```
+
+## Command binders
+
+A command binder does for `BindCommand` what a provider does for observation. It implements `ICreatesCommandBinding`, and the binder with the highest affinity for a control type serves the call. Without a binder, the generated binding hands the view model's command to the button. This excerpt binds the add button before any binder is registered and checks who holds the command.
+
+```csharp
+using (view.BindCommand(viewModel, x => x.AddCommand, v => v.AddButton))
+{
+    Console.WriteLine($"The button has no command: {view.AddButton.Command is null}");
+    Console.WriteLine($"The button holds the view model's command: {ReferenceEquals(viewModel.AddCommand, view.AddButton.Command)}");
+}
+```
+
+```text
+The button has no command: False
+The button holds the view model's command: True
+```
+
+The interface has three `BindCommandToObject` overloads. One binds to the control's default event. One binds to an event you name. The third takes `addHandler` and `removeHandler` delegates and needs no event lookup. `GetAffinityForObject<T>` receives `hasEventTarget`, which is true when the caller names an event.
+
+### Write a command binder
+
+`ClickCommandBinder` serves a MAUI `Button`. It bids `ExactType` (10) for a `Button` and 0 for other controls. It returns null when there is no command or the target is not a button. Returning null means no binding was created. These two members are the first part of the binder, and they show how a binder claims a control type.
+
+```csharp
+public int GetAffinityForObject<T>(bool hasEventTarget) =>
+    typeof(Button).IsAssignableFrom(typeof(T)) ? BindingAffinity.ExactType : 0;
+
+public IDisposable? BindCommandToObject<T>(ICommand? command, T? target, IObservable<object?> commandParameter)
+    where T : class =>
+    command is null || target is not Button button
+        ? null
+        : AttachToClicks(command, button, commandParameter, ObserveClicks(button));
+```
+
+`AttachToClicks` builds the binding from Primitives parts. A `BehaviorSignal` keeps the latest command parameter, and it starts with null. The binder feeds it from the `commandParameter` stream. A click runs the command only when `CanExecute` accepts the parameter. `Merge` joins the parameter stream with each `CanExecuteChanged` event, which re-reads the parameter, so `button.IsEnabled` follows `CanExecute`. An `ActionDisposable` puts the original `IsEnabled` back. A `MultipleDisposable` bundles every part, so disposing the binding detaches all of them. See [signals](../primitives/signals.md) and [disposables](../primitives/disposables.md).
+
+```csharp
+var wasEnabled = button.IsEnabled;
+BehaviorSignal<object?> parameter = new(null);
+var canExecuteChanged = Signal.FromEventPattern(handler => command.CanExecuteChanged += handler, handler => command.CanExecuteChanged -= handler);
+
+return new(
+    commandParameter.Subscribe(parameter.OnNext),
+    clicks.Where(_ => command.CanExecute(parameter.Value)).Subscribe(_ => command.Execute(parameter.Value)),
+    parameter.Merge(canExecuteChanged.Select(_ => parameter.Value)).Select(command.CanExecute).Subscribe(canRun => button.IsEnabled = canRun),
+    new ActionDisposable(() => button.IsEnabled = wasEnabled),
+    parameter);
+```
+
+Register a binder with `WithCommandBinder`. `CommandBinderService.GetBinder<T>` returns the binder with the highest affinity for a control type. The first registered binder wins a tie, and the method returns null when every binder bids 0 or less.
+
+```csharp
+IReactiveUIBindingBuilder builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+
+_ = builder.WithCoreServices().WithCommandBinder(binder).BuildApp();
+
+Console.WriteLine($"Binder for a button: {ReferenceEquals(binder, CommandBinderService.GetBinder<Button>(false))}");
+Console.WriteLine($"Binder for a button with an event target: {ReferenceEquals(binder, CommandBinderService.GetBinder<Button>(true))}");
+Console.WriteLine($"No binder for an entry: {CommandBinderService.GetBinder<Entry>(false) is null}");
+```
+
+```text
+Binder for a button: True
+Binder for a button with an event target: True
+No binder for an entry: True
+```
+
+`CommandBindingAffinityChecker.HasHigherAffinityPlugin<T>` tells generated code whether a registered binder outranks the generated mechanism for a control type. It reads the registrations on every call, so it needs no `Refresh`. The loop below runs over every `BindingAffinity` score. The binder bids 10, so it outranks the scores from `Fallback` up to `WinFormsEvent`, and it loses at `ExactType` and `Kvo`. An `Entry` has no binder, so nothing outranks the fallback.
+
+```csharp
+foreach (var (name, score) in scores)
+{
+    Console.WriteLine($"{name} ({score}): binder outranks it = {CommandBindingAffinityChecker.HasHigherAffinityPlugin<Button>(score, false)}");
+}
+
+Console.WriteLine($"Binder outranks the fallback for an entry: {CommandBindingAffinityChecker.HasHigherAffinityPlugin<Entry>(BindingAffinity.Fallback, false)}");
+```
+
+```text
+Fallback (1): binder outranks it = True
+DefaultInternalTypeConverter (2): binder outranks it = True
+DefaultEvent (3): binder outranks it = True
+WpfDependencyObject (4): binder outranks it = True
+EventEnabledControl (4): binder outranks it = True
+Explicit (5): binder outranks it = True
+WinUiDependencyObject (6): binder outranks it = True
+WinFormsEvent (8): binder outranks it = True
+ExactType (10): binder outranks it = False
+Kvo (15): binder outranks it = False
+Binder outranks the fallback for an entry: False
+```
+
+With the binder registered, `BindCommand` never touches the button's own `Command` property. The binder enables the button while the command can run and runs the command on each click. A click after you dispose the binding does nothing. The binder prints a line each time it attaches.
+
+```csharp
+var added = viewModel.WhenChanged(x => x.SelectedItem).Where(static item => item is not null).Take(1).GetAwaiter();
+
+using (view.BindCommand(viewModel, x => x.AddCommand, v => v.AddButton))
+{
+    Console.WriteLine($"The button has no command: {view.AddButton.Command is null}");
+    Console.WriteLine($"Enabled with no title: {view.AddButton.IsEnabled}");
+
+    viewModel.NewTitle = PlumberTitle;
+
+    Console.WriteLine($"Enabled with a title: {view.AddButton.IsEnabled}");
+
+    ((IButtonController)view.AddButton).SendClicked();
+    await added;
+
+    Console.WriteLine(viewModel.Items[^1].Title);
+}
+
+var itemCount = viewModel.Items.Count;
+
+viewModel.NewTitle = PlumberTitle;
+((IButtonController)view.AddButton).SendClicked();
+
+Console.WriteLine($"A click after disposing adds nothing: {viewModel.Items.Count == itemCount}");
+```
+
+```text
+The click binder is attached to the Add button
+The button has no command: True
+Enabled with no title: False
+Enabled with a title: True
+Call the plumber
+A click after disposing adds nothing: True
+```
+
+A stream of parameters is another `BindCommand` argument. The binder passes the latest value to the command, and it enables the button only while the command accepts that value. Here the upload button stays disabled until the first file arrives on the stream. See [Bindings](bindings.md).
+
+```csharp
+var stored = browser.WhenChanged(x => x.Objects).Where(static objects => objects.Any(static item => item.Key == ScreenshotName)).Take(1).GetAwaiter();
+
+using (view.BindCommand(browser, x => x.UploadCommand, v => v.UploadButton, uploads))
+{
+    Console.WriteLine($"Enabled with no file: {view.UploadButton.IsEnabled}");
+
+    uploads.OnNext(new(ScreenshotName, ScreenshotBytes, PngType));
+
+    Console.WriteLine($"Enabled with a file: {view.UploadButton.IsEnabled}");
+
+    ((IButtonController)view.UploadButton).SendClicked();
+    await stored;
+}
+
+Console.WriteLine($"Objects: {browser.Objects.Count}");
+Console.WriteLine($"No error: {browser.ErrorMessage.Length == 0}");
+```
+
+```text
+The click binder is attached to the Upload button
+Enabled with no file: False
+Enabled with a file: True
+Objects: 6
+No error: True
+```
+
+Name an event and the binder receives the event name and the type of its event data. `ClickCommandBinder` serves only `Clicked` and returns null for any other name. This excerpt names the `Clicked` event, which lets a control offer several events and the view choose one.
+
+```csharp
+browser.CurrentPrefix = PhotoFolder;
+
+var listed = browser.WhenChanged(x => x.Objects).Skip(1).Take(1).GetAwaiter();
+
+using (view.BindCommand(browser, x => x.RefreshCommand, v => v.RefreshButton, nameof(Button.Clicked)))
+{
+    ((IButtonController)view.RefreshButton).SendClicked();
+    await listed;
+}
+
+Console.WriteLine(browser.Objects.Count);
+```
+
+```text
+The click binder is asked for the Clicked event, which carries EventArgs
+The click binder is attached to the Refresh button
+2
+```
+
+You can also call a binder yourself. The default-event overload takes the command, the target and a parameter stream. `ImmutableEmptySignal<object>` produces no values, so the parameter stays null.
+
+```csharp
+browser.CurrentPrefix = string.Empty;
+
+var listed = browser.WhenChanged(x => x.Objects).Skip(1).Take(1).GetAwaiter();
+
+using (binder.BindCommandToObject(browser.RefreshCommand, view.RefreshButton, ImmutableEmptySignal<object>.Instance))
+{
+    ((IButtonController)view.RefreshButton).SendClicked();
+    await listed;
+}
+
+Console.WriteLine(browser.Objects.Count);
+```
+
+```text
+The click binder is attached to the Refresh button
+6
+```
+
+The overload with `addHandler` and `removeHandler` names the event through two delegates. The binder subscribes and unsubscribes through them, so nothing is looked up by name and the call is compatible with Native AOT. The excerpt binds the reconnect button, which starts disabled-looking work only when the command can run, and prints the link state after the click.
+
+```csharp
+var button = view.ConnectButton;
+storage.Disconnect();
+
+var connected = browser.WhenChanged(x => x.ConnectionStatus).Where(static state => state == ConnectionState.Connected).Take(1).GetAwaiter();
+
+using (binder.BindCommandToObject<Button, EventArgs>(
+    browser.ConnectCommand,
+    button,
+    ImmutableEmptySignal<object>.Instance,
+    handler => button.Clicked += handler.Invoke,
+    handler => button.Clicked -= handler.Invoke))
+{
+    Console.WriteLine($"Enabled while disconnected: {button.IsEnabled}");
+
+    ((IButtonController)button).SendClicked();
+    await connected;
+}
+
+Console.WriteLine($"Connection: {storage.Connection.State}");
+```
+
+```text
+The click binder is attached to the Reconnect button
+Enabled while disconnected: True
+Connection: Connected
+```
+
+## Run a command for each value
+
+`CommandInvoker.Invoke` executes a command with each value a stream produces. It asks `CanExecute` for each value and drops a value the command refuses. An error from the stream is rethrown on the thread that raised it, and completion is ignored. The first overload takes one fixed command. Disposing the result stops the executions. This excerpt lists the objects again each time the prefix property changes, and it shows that a change after disposal lists nothing.
+
+```csharp
+browser.CurrentPrefix = string.Empty;
+
+var listed = browser.WhenChanged(x => x.Objects).Skip(1).Take(1).GetAwaiter();
+
+using (CommandInvoker.Invoke(browser.WhenChanged(x => x.CurrentPrefix), browser.RefreshCommand))
+{
+    await listed;
+
+    Console.WriteLine($"Objects in the whole bucket: {browser.Objects.Count}");
+
+    listed = browser.WhenChanged(x => x.Objects).Skip(1).Take(1).GetAwaiter();
+    browser.CurrentPrefix = PhotoFolder;
+    await listed;
+
+    Console.WriteLine($"Objects in the photo folder: {browser.Objects.Count}");
+}
+
+browser.CurrentPrefix = string.Empty;
+
+Console.WriteLine($"Objects after disposing: {browser.Objects.Count}");
+```
+
+```text
+Objects in the whole bucket: 6
+Objects in the photo folder: 2
+Objects after disposing: 2
+```
+
+The second overload takes a stream of commands and executes whichever command arrived last. It subscribes to the commands first, so a command the stream produces on subscription is held before any value can arrive. A null command drops the values that arrive while it is current, and a later command takes over from the next value. Replacing the command runs nothing by itself. The excerpt sends a file while the command is null, which drops it, and then sends a second file after a command arrives.
+
+```csharp
+browser.CurrentPrefix = string.Empty;
+await browser.LoadObjectsAsync().ConfigureAwait(false);
+
+var objectCount = browser.Objects.Count;
+var stored = browser.WhenChanged(x => x.Objects).Where(static objects => objects.Any(static item => item.Key == ThirdScreenshotName)).Take(1).GetAwaiter();
+
+using (CommandInvoker.Invoke(uploads, commands))
+{
+    commands.OnNext(null);
+    uploads.OnNext(new(SecondScreenshotName, ScreenshotBytes, PngType));
+
+    Console.WriteLine($"No command yet, nothing uploaded: {browser.Objects.Count == objectCount}");
+
+    commands.OnNext(browser.UploadCommand);
+    uploads.OnNext(new(ThirdScreenshotName, ScreenshotBytes, PngType));
+    await stored;
+}
+
+Console.WriteLine($"One file uploaded: {browser.Objects.Count == objectCount + 1}");
+Console.WriteLine($"The first file was dropped: {!browser.Objects.Any(static item => item.Key == SecondScreenshotName)}");
+```
+
+```text
+No command yet, nothing uploaded: True
+One file uploaded: True
+The first file was dropped: True
+```
+
+## The observable types
+
+Generated code and the run-time engine build the types below. You rarely build one yourself. The examples build each by hand to show what it delivers. Each type also accepts an observer object in `Subscribe`. `Witness.Create<T>` builds one from a lambda, as [Writing your own operator](../primitives/advanced.md) shows.
+
+| Type | What it delivers |
+| --- | --- |
+| `PropertyObservable<T>` | The value at subscription and after each `PropertyChanged` for one property. |
+| `PropertyChangingObservable<T>` | The value at subscription and before each `PropertyChanging` for one property. |
+| `NotifyPropertyChangedObservable` | An `IObservedChange` for each notification, with no value. |
+| `EventObservable<T>` | The value at subscription and after each raise of a plain event. |
+| `UnchangingPropertyObservable<T>` | One value, and then nothing. |
+| `AppliedChangeObservable` | Each `BindingChange` a binding writes. |
+| `CombineLatestObservable` | A result from the latest value of two to sixteen sources. |
+| `PluginPropertyObservable<T>` | The value read after each provider notification. |
+| `PluginObservationSource` | The choice between a generated observation and a provider. |
+
+`PropertyObservable<T>` takes the source, the property name, a getter and a flag. With the flag true it drops a value equal to the last one. A change notification with a null or empty property name applies to every property. This excerpt observes whether an item is urgent. Setting the priority to `Low` repeats `False`, so the observable drops it, and a subscriber never sees a change that is not one.
+
+```csharp
+TodoItem item = new() { Title = RegistrationTitle };
+PropertyObservable<bool> isUrgent = new(item, nameof(TodoItem.Priority), static source => ((TodoItem)source).Priority == TodoPriority.High, true);
+
+using (isUrgent.Subscribe(Console.WriteLine))
+{
+    item.Priority = TodoPriority.Low;
+    item.Priority = TodoPriority.High;
+}
+```
+
+```text
+False
+True
+```
+
+The next excerpt builds the same observable with the flag false. Use this form when every change matters, even one that repeats the last value. Each priority change delivers a value.
+
+```csharp
+TodoItem item = new() { Title = RegistrationTitle };
+PropertyObservable<bool> isUrgent = new(item, nameof(TodoItem.Priority), static source => ((TodoItem)source).Priority == TodoPriority.High, false);
+
+using (isUrgent.Subscribe(Console.WriteLine))
+{
+    item.Priority = TodoPriority.Low;
+    item.Priority = TodoPriority.High;
+}
+```
+
+```text
+False
+False
+True
+```
+
+Any of these observables also accepts an observer object in place of a lambda. An observer is an `IObserver<T>`, and `Witness.Create<T>` builds one from a lambda. The excerpt subscribes the first observable that way and prints the same values.
+
+```csharp
+TodoItem item = new() { Title = RegistrationTitle };
+PropertyObservable<bool> isUrgent = new(item, nameof(TodoItem.Priority), static source => ((TodoItem)source).Priority == TodoPriority.High, true);
+var observer = Witness.Create<bool>(Console.WriteLine);
+
+using (isUrgent.Subscribe(observer))
+{
+    item.Priority = TodoPriority.Low;
+    item.Priority = TodoPriority.High;
+}
+```
+
+```text
+False
+True
+```
+
+`PropertyChangingObservable<T>` reads the value before each edit. It does not drop repeats, because the value has not changed when the event fires. The first line is the value at subscription. The next two are the values before each edit.
+
+```csharp
+DraftTodo draft = new() { Title = RegistrationTitle };
+PropertyChangingObservable<string> beforeChange = new(draft, nameof(DraftTodo.Title), static source => ((DraftTodo)source).Title);
+
+using (beforeChange.Subscribe(Console.WriteLine))
+{
+    draft.Title = RenamedTitle;
+    draft.Title = FinalTitle;
+    draft.Notes = RegistrationNotes;
+}
+```
+
+```text
+Renew car registration
+Renew car registration
+Renew car registration online
+```
+
+The same observable works with an observer object. This excerpt reads the title before one edit and prints two lines, the value at subscription and the value before the edit.
+
+```csharp
+DraftTodo draft = new() { Title = RegistrationTitle };
+PropertyChangingObservable<string> beforeChange = new(draft, nameof(DraftTodo.Title), static source => ((DraftTodo)source).Title);
+var observer = Witness.Create<string>(Console.WriteLine);
+
+using (beforeChange.Subscribe(observer))
+{
+    draft.Title = RenamedTitle;
+}
+```
+
+```text
+Renew car registration
+Renew car registration
+```
+
+`NotifyPropertyChangedObservable` delivers no value on subscription. Each change names the sender and the expression, and you read the property from the sender. Pass `true` as the last argument to observe before the change. This excerpt observes after the change and prints the property name with the new title. The `Notes` edit is ignored, so the observable reports only the property you named.
+
+```csharp
+DraftTodo draft = new() { Title = RegistrationTitle };
+Expression<Func<DraftTodo, string>> title = x => x.Title;
+NotifyPropertyChangedObservable afterChange = new(draft, title.Body, nameof(DraftTodo.Title), false);
+
+using (afterChange.Subscribe(static change => Console.WriteLine($"{change.GetPropertyName()}: {((DraftTodo)change.Sender).Title}")))
+{
+    draft.Title = RenamedTitle;
+    draft.Notes = RegistrationNotes;
+}
+```
+
+```text
+Title: Renew car registration online
+```
+
+With `true` as the last argument, the observable reports before the change. Reading the property from the sender then gives the old title, which is useful when you want to keep the value that is about to be replaced. The `Notes` edit is ignored.
+
+```csharp
+DraftTodo draft = new() { Title = RegistrationTitle };
+Expression<Func<DraftTodo, string>> title = x => x.Title;
+NotifyPropertyChangedObservable beforeChange = new(draft, title.Body, nameof(DraftTodo.Title), true);
+
+using (beforeChange.Subscribe(static change => Console.WriteLine($"{change.GetPropertyName()}: {((DraftTodo)change.Sender).Title}")))
+{
+    draft.Title = RenamedTitle;
+    draft.Notes = RegistrationNotes;
+}
+```
+
+```text
+Title: Renew car registration
+```
+
+The next excerpt passes an observer object and prints only the property name of each change.
+
+```csharp
+DraftTodo draft = new() { Title = RegistrationTitle };
+Expression<Func<DraftTodo, string>> title = x => x.Title;
+NotifyPropertyChangedObservable afterChange = new(draft, title.Body, nameof(DraftTodo.Title), false);
+var observer = Witness.Create<IObservedChange<object, object?>>(static change => Console.WriteLine(change.GetPropertyName()));
+
+using (afterChange.Subscribe(observer))
+{
+    draft.Title = RenamedTitle;
+}
+```
+
+```text
+Title
+```
+
+`EventObservable<T>` observes a class that raises a plain event. It takes delegates that add and remove the handler, a getter and the flag that drops repeats. It ignores the event arguments and reads the getter on subscription and on each raise. It never completes. Use it for a class that offers only a plain event. This excerpt observes whether a connection is open. A repeated `False` is dropped, and the event after disposal delivers nothing.
+
+```csharp
+StorageConnection connection = new() { Endpoint = StorageEndpoint };
+EventObservable<bool> isOpen = new(
+    handler => connection.StateChanged += handler,
+    handler => connection.StateChanged -= handler,
+    () => connection.State == ConnectionState.Connected,
+    true);
+
+using (isOpen.Subscribe(Console.WriteLine))
+{
+    connection.State = ConnectionState.Connecting;
+    connection.State = ConnectionState.Connected;
+    connection.State = ConnectionState.Disconnected;
+}
+
+connection.State = ConnectionState.Connected;
+```
+
+```text
+False
+True
+False
+```
+
+With the flag false, every event delivers a value, including a repeat. This excerpt raises three events and receives the value at subscription plus one value for each event.
+
+```csharp
+StorageConnection connection = new() { Endpoint = StorageEndpoint };
+EventObservable<bool> isOpen = new(
+    handler => connection.StateChanged += handler,
+    handler => connection.StateChanged -= handler,
+    () => connection.State == ConnectionState.Connected,
+    false);
+
+using (isOpen.Subscribe(Console.WriteLine))
+{
+    connection.State = ConnectionState.Connecting;
+    connection.State = ConnectionState.Connected;
+    connection.State = ConnectionState.Disconnected;
+}
+```
+
+```text
+False
+False
+True
+False
+```
+
+The event observable also takes an observer object. This excerpt raises two events and prints two values, because the repeated `False` is dropped.
+
+```csharp
+StorageConnection connection = new() { Endpoint = StorageEndpoint };
+EventObservable<bool> isOpen = new(
+    handler => connection.StateChanged += handler,
+    handler => connection.StateChanged -= handler,
+    () => connection.State == ConnectionState.Connected,
+    true);
+var observer = Witness.Create<bool>(Console.WriteLine);
+
+using (isOpen.Subscribe(observer))
+{
+    connection.State = ConnectionState.Connecting;
+    connection.State = ConnectionState.Connected;
+}
+```
+
+```text
+False
+True
+```
+
+`UnchangingPropertyObservable<T>` observes a property whose owner raises no notification. It delivers the value once and stays silent. It never completes, so a binding that observes it stays subscribed. The error and completion handlers below never run.
+
+```csharp
+StorageObject file = new() { Key = "photos/2026/launch.png" };
+UnchangingPropertyObservable<string> key = new(file.Key);
+
+using (key.Subscribe(
+    Console.WriteLine,
+    static error => Console.WriteLine($"Failed: {error.Message}"),
+    static () => Console.WriteLine("Completed")))
+{
+    file.Key = "photos/2026/renamed.png";
+}
+```
+
+```text
+photos/2026/launch.png
+```
+
+With an observer object, the subscription delivers the same single value. Keep the returned subscription in a `using` variable so it is disposed at the end of the method.
+
+```csharp
+StorageObject file = new() { Key = "photos/2026/launch.png" };
+UnchangingPropertyObservable<string> key = new(file.Key);
+var observer = Witness.Create<string>(Console.WriteLine);
+
+using var subscription = key.Subscribe(observer);
+```
+
+```text
+photos/2026/launch.png
+```
+
+`AppliedChangeObservable` reports the changes a binding wrote. `OnNext` publishes a `BindingChange`, which carries the `Value` and a `FromViewModel` flag. The flag separates an edit from the echo of one. `HasObservers` tells you whether anyone is subscribed, and it turns false again when a subscriber disposes its subscription. The excerpt shows a subscriber that is counted while it listens and forgotten after it disposes its subscription. See [Bindings](bindings.md).
+
+```csharp
+AppliedChangeObservable applied = new();
+
+Console.WriteLine($"Observers at the start: {applied.HasObservers}");
+
+using (applied.Subscribe(static change => Console.WriteLine($"{change.Value}, from the view model: {change.FromViewModel}")))
+{
+    Console.WriteLine($"Observers while subscribed: {applied.HasObservers}");
+
+    applied.OnNext(new(RenamedTitle, true));
+    applied.OnNext(new(FinalTitle, false));
+}
+
+applied.OnNext(new(RegistrationTitle, true));
+
+Console.WriteLine($"Observers after disposing: {applied.HasObservers}");
+```
+
+```text
+Observers at the start: False
+Observers while subscribed: True
+Renew car registration online, from the view model: True
+Renew car registration by post, from the view model: False
+Observers after disposing: False
+```
+
+An observer object receives the same `BindingChange` values. This excerpt publishes one change and prints it.
+
+```csharp
+AppliedChangeObservable applied = new();
+var observer = Witness.Create<BindingChange>(static change => Console.WriteLine($"{change.Value}, from the view model: {change.FromViewModel}"));
+
+using (applied.Subscribe(observer))
+{
+    applied.OnNext(new(RenamedTitle, true));
+}
+```
+
+```text
+Renew car registration online, from the view model: True
+```
+
+A two-way `Bind` returns a binding whose `Changed` property is an `AppliedChangeObservable`. The next excerpt edits the entry, then the view model, and reads the side that produced each change. The `FromViewModel` flag lets a subscriber tell an edit from the echo of one, and the entry ends up showing the view model's value.
+
+```csharp
+TodoListViewModel viewModel = new(InMemoryTodoStore.CreateSeeded());
+TodoView view = new() { ViewModel = viewModel };
+
+using var binding = view.Bind(viewModel, x => x.NewTitle, v => v.NewTitleTextBox.Text);
+using var subscription = binding.Changed.Subscribe(static change => Console.WriteLine($"{change.Value}, from the view model: {change.FromViewModel}"));
+
+view.NewTitleTextBox.Text = RenamedTitle;
+viewModel.NewTitle = FinalTitle;
+
+Console.WriteLine($"The entry shows: {view.NewTitleTextBox.Text}");
+```
+
+```text
+Renew car registration online, from the view model: False
+Renew car registration by post, from the view model: True
+The entry shows: Renew car registration by post
+```
+
+## Combine several sources
+
+`CombineLatestObservable.Create` combines two to sixteen sources. It delivers a result once every source has produced a value, and again each time any source produces a new one. This excerpt joins the title and the done flag of an item into a checklist line. `Title(item)` and `IsDone(item)` are helpers in the example that return a `PropertyObservable<T>`.
+
+```csharp
+TodoItem item = new() { Title = RegistrationTitle };
+
+using (CombineLatestObservable
+    .Create(Title(item), IsDone(item), static (title, isDone) => (isDone ? DoneMark : OpenMark) + title)
+    .Subscribe(Console.WriteLine))
+{
+    item.IsDone = true;
+    item.Title = RenamedTitle;
+}
+```
+
+```text
+[ ] Renew car registration
+[x] Renew car registration
+[x] Renew car registration online
+```
+
+Three sources work the same way. This excerpt joins the title, the done flag and the priority into one summary. Changing only the priority delivers a new summary, because the other two sources keep their latest values.
+
+```csharp
+TodoItem item = new() { Title = RegistrationTitle };
+
+using (CombineLatestObservable
+    .Create(Title(item), IsDone(item), Priority(item), static (title, isDone, priority) => $"{title} {isDone} {priority}")
+    .Subscribe(Console.WriteLine))
+{
+    item.Priority = TodoPriority.High;
+}
+```
+
+```text
+Renew car registration False Normal
+Renew car registration False High
+```
+
+`CombineLatestObservable.Create` accepts up to sixteen sources and follows the same pattern for every count. You pass the sources and then a selector that takes one value for each source. The [example project](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/mechanisms/CombineLatestExamples.cs) has one method for each count from four to sixteen.
+
+## Where to go next
+
+- [Observing](observing.md) covers `WhenChanged` and the other observation methods.
+- [Bindings](bindings.md) covers `BindCommand` and the other binding methods.
+- [Threading and platforms](threading.md) covers the platform mechanisms.
+- [Setup](setup.md) covers the builder and `WithCoreServices`.
+- [Unsafe twins and the runtime fallback](unsafe.md) covers call sites the generator cannot read.
+- [API reference](api.md) lists every public type and member.
+
+## API reference
+
+| Member | What it does | Type and values | Notes |
+| --- | --- | --- | --- |
+| [`BindingAffinity`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingAffinity.cs) | Holds the scores that providers, command binders and converters share. | Static class of read-only `int` fields: `Fallback` 1, `DefaultInternalTypeConverter` 2, `DefaultEvent` 3, `WpfDependencyObject` 4, `EventEnabledControl` 4, `Explicit` 5, `WinUiDependencyObject` 6, `WinFormsEvent` 8, `ExactType` 10, `Kvo` 15. | A higher score wins. Zero means the candidate does not apply. |
+| [`ICreatesObservableForProperty`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/ICreatesObservableForProperty.cs) | Supplies one mechanism for observing properties, called a provider. | Interface with `GetAffinityForObject` and `GetNotificationForProperty`. | The registration with the highest affinity for a type and property serves the observation. |
+| [`ICreatesObservableForProperty.GetAffinityForObject`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/ICreatesObservableForProperty.cs) | Scores how well the provider can observe a property of a type. | `Type type`, `string propertyName`, `bool beforeChanged`. Returns `int`. | A positive score means the provider can observe the property. Zero or a negative score means it cannot. |
+| [`ICreatesObservableForProperty.GetNotificationForProperty`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/ICreatesObservableForProperty.cs) | Creates a stream that delivers each time the property changes. | `object sender`, `Expression expression`, `string propertyName`, `bool beforeChanged`, `bool suppressWarnings`. Returns `IObservable<IObservedChange<object, object?>>`. | Callers read the current value from `sender`, not from the change. `suppressWarnings` silences the warning for a property that cannot notify. |
+| [`CreatesObservableForPropertyMixins.GetAffinityForObject`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/CreatesObservableForPropertyMixins.cs) | Asks a provider for its after-change score. | Extension on `ICreatesObservableForProperty` with `Type type` and `string propertyName`. Returns `int`. | Passes `false` for `beforeChanged`. Throws `ArgumentNullException` when the provider is null. |
+| [`CreatesObservableForPropertyMixins.GetNotificationForProperty`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/CreatesObservableForPropertyMixins.cs) | Creates a change stream without naming the two flags. | Extension on `ICreatesObservableForProperty` with `object sender`, `Expression expression`, `string propertyName` and an optional `bool beforeChanged`. Returns `IObservable<IObservedChange<object, object?>>`. | Passes `false` for `suppressWarnings`, and for `beforeChanged` when you omit it. Throws `ArgumentNullException` when the provider is null. |
+| [`INPCObservableForProperty`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/INPCObservableForProperty.cs) | Provides the `PropertyChanged` mechanism. | Public class with a parameterless constructor. | `WithCoreServices` registers it. |
+| [`INPCObservableForProperty.GetAffinityForObject`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/INPCObservableForProperty.cs) | Scores a type by the notification interface it implements. | Returns `BindingAffinity.Explicit` (5) or 0. | Needs `INotifyPropertyChanged` for after-change requests and `INotifyPropertyChanging` for before-change requests. Ignores the property name. |
+| [`INPCObservableForProperty.GetNotificationForProperty`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/INPCObservableForProperty.cs) | Delivers a change each time the sender raises a notification for the property. | Returns `IObservable<IObservedChange<object, object?>>`. | Returns a stream that never delivers when the sender implements neither interface. A before-change request on a sender without `INotifyPropertyChanging` uses `PropertyChanged`. An indexer matches the name followed by `[]`. Ignores `suppressWarnings`. Throws `ArgumentNullException` when `expression` is null. |
+| [`POCOObservableForProperty`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/POCOObservableForProperty.cs) | Provides the fallback mechanism for a class that raises nothing. | Sealed public class with a parameterless constructor. | `WithCoreServices` registers it after `INPCObservableForProperty`. |
+| [`POCOObservableForProperty.GetAffinityForObject`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/POCOObservableForProperty.cs) | Scores every type and property at the lowest positive score. | Returns `BindingAffinity.Fallback` (1). | Ignores `beforeChanged`. Throws `ArgumentNullException` when `type` or `propertyName` is null. |
+| [`POCOObservableForProperty.GetNotificationForProperty`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/POCOObservableForProperty.cs) | Delivers one change on subscription and then nothing. | Returns `IObservable<IObservedChange<object, object?>>`. | Never completes, so a binding stays subscribed. Writes a debug message once for each type and property unless `suppressWarnings` is true. Ignores `beforeChanged`. Throws `ArgumentNullException` when `sender`, `expression` or `propertyName` is null. |
+| [`ObservationAffinityChecker`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/ObservationAffinityChecker.cs) | Finds a registered provider that outranks the mechanism the generator picked. | Static class. | Hidden from IntelliSense. Reads registrations on first use and caches the best score for each type, property and timing. |
+| [`ObservationAffinityChecker.FindHigherAffinityPlugin`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/ObservationAffinityChecker.cs) | Returns the provider that beats a given score. | `Type type`, `string propertyName`, `int generatedAffinity`, `bool beforeChanged`. Returns `ICreatesObservableForProperty?`. | Returns null when no provider scores strictly higher, so a tie keeps the generated mechanism. Throws `ArgumentNullException` when `type` or `propertyName` is null. |
+| [`ObservationAffinityChecker.HasHigherAffinityPlugin`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/ObservationAffinityChecker.cs) | Tells you whether a provider beats a given score. | Same four arguments as `FindHigherAffinityPlugin`. Returns `bool`. | True exactly when `FindHigherAffinityPlugin` returns a provider. |
+| [`ObservationAffinityChecker.Refresh`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/ObservationAffinityChecker.cs) | Clears the cached registrations and scores. | No arguments. | Call it after you register a provider. A lookup that runs at the same time can finish with the registrations it read. |
+| [`PluginObservationSource.Choose`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Observables/PluginObservationSource.cs) | Picks between a generated observation and a provider that outranks it. | `object source`, `Expression expression`, `string propertyName`, `bool beforeChange`, `int generatedAffinity`, `Func<object, T?> getter`, `IObservable<T> generated`. Returns `IObservable<T>`. | Returns `generated` when no provider outranks `generatedAffinity`. Otherwise it returns a `PluginPropertyObservable<T>` that keeps repeated values. Static class, hidden from IntelliSense. Throws `ArgumentNullException` when `source` or `generated` is null. |
+| [`PluginPropertyObservable<T>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Observables/PluginPropertyObservable.cs) | Observes one property through a provider. The provider says when the property changed and the getter reads the value. | Sealed class. Constructor: `ICreatesObservableForProperty plugin`, `object source`, `Expression expression`, `string propertyName`, `Func<object, T?> getter`, `bool beforeChange`, `bool distinctUntilChanged`. `Subscribe(IObserver<T>)` returns `IDisposable`. | Delivers the current value on subscription and after each notification. Passes on a provider error or completion after any value that waits to be read. Hidden from IntelliSense. Throws `ArgumentNullException` for a null reference argument. |
+| [`CommandBindingAffinityChecker.HasHigherAffinityPlugin<T>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/CommandBindingAffinityChecker.cs) | Tells you whether a registered binder outranks the generated command binding for a control type. | `T` is the control type. `int generatedAffinity`, `bool hasEventTarget`. Returns `bool`. | Reads the registrations on every call, so it needs no refresh. Static class, hidden from IntelliSense. |
+| [`CommandBinderService.GetBinder<T>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/CommandBinding/CommandBinderService.cs) | Returns the binder with the highest affinity for a control type. | `T` is the control type. `bool hasEventTarget`. Returns `ICreatesCommandBinding?`. | The first registered binder wins a tie. Returns null when every binder scores 0 or less. Static class, hidden from IntelliSense. |
+| [`CommandInvoker.Invoke`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/CommandBinding/CommandInvoker.cs) | Runs a command with each value a stream produces. | `IObservable<T> source` plus either an `ICommand` or an `IObservable<ICommand?>`. Returns `IDisposable`. | Skips a value that `CanExecute` refuses. With a stream of commands, a null command drops values and the latest command runs. A source error is rethrown on the thread that raised it, and completion is ignored. Throws `ArgumentNullException` for a null argument. Static class, hidden from IntelliSense. |
+| [`ICreatesCommandBinding`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/ICreatesCommandBinding.cs) | Binds an `ICommand` to a control. | Interface with `GetAffinityForObject<T>` and three `BindCommandToObject` overloads. | The binder with the highest affinity for a control type serves `BindCommand`. Register one with `WithCommandBinder`. |
+| [`ICreatesCommandBinding.GetAffinityForObject`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/ICreatesCommandBinding.cs) | Scores how well the binder fits a control type. | `T` is the control type. `bool hasEventTarget`. Returns `int`. | A positive score means the binder can bind the control. Zero or a negative score means it cannot. `hasEventTarget` is true when the caller names an event. |
+| [`ICreatesCommandBinding.BindCommandToObject`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/ICreatesCommandBinding.cs) | Binds a command to a control. | `ICommand? command`, `T? target`, `IObservable<object?> commandParameter`, and one of three forms: nothing (default event), `string eventName`, or `addHandler` and `removeHandler` delegates. Returns `IDisposable?`. | Returns null when no binding is created, and a null command creates none. The default-event and named-event forms carry `RequiresUnreferencedCode`. The delegate form needs no event lookup. |
+| [`AppliedChangeObservable`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Observables/AppliedChangeObservable.cs) | Carries the changes a two-way binding wrote. | Sealed class with a parameterless constructor. `Subscribe(IObserver<BindingChange>)` returns `IDisposable`. | Disposing the subscription removes the observer. Throws `ArgumentNullException` for a null observer. |
+| [`AppliedChangeObservable.OnNext`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Observables/AppliedChangeObservable.cs) | Reports a change the binding wrote. | `BindingChange value`, which holds `object? Value` and `bool FromViewModel`. | Reaches every observer subscribed at that moment. `FromViewModel` tells an edit from the echo of one. |
+| [`AppliedChangeObservable.HasObservers`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Observables/AppliedChangeObservable.cs) | Tells you whether anyone is subscribed. | Read-only `bool` property. | False again after the last subscriber disposes its subscription. |
+| [`CombineLatestObservable.Create`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Observables/CombineLatestObservable.cs) | Combines the latest value of several sources. | Two to sixteen sources, `IObservable<T1>` up to `IObservable<T16>`, and a `Func<T1, ..., T16, TResult>` selector. Returns `IObservable<TResult>`. | Delivers once every source has produced a value, then again on each new value from any source. Static class, hidden from IntelliSense. |
+| [`EventObservable<T>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Observables/EventObservable.cs) | Observes a value that changes when a plain event is raised. | Sealed class. Constructor: `Action<EventHandler> addHandler`, `Action<EventHandler> removeHandler`, `Func<T> getter`, `bool distinctUntilChanged`. `Subscribe(IObserver<T>)` returns `IDisposable`. | Reads the getter on subscription and on each raise, and ignores the event arguments. With the flag true it drops a value equal to the last one. Never completes. A getter that throws on subscription makes `Subscribe` throw after the handler is removed. Hidden from IntelliSense. Throws `ArgumentNullException` for a null argument. |
+| [`NotifyPropertyChangedObservable`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Observables/NotifyPropertyChangedObservable.cs) | Delivers an observed change for each notification about one property. | Sealed class. Constructor: `object sender`, `Expression expression`, `string expectedName`, `bool beforeChanged`. `Subscribe(IObserver<IObservedChange<object, object?>>)` returns `IDisposable`. | Delivers nothing on subscription, and a change carries no value. A null or empty notification name matches every property. Observes `PropertyChanging` when `beforeChanged` is true and the sender implements it, and `PropertyChanged` otherwise. Never completes. Hidden from IntelliSense. Throws `ArgumentNullException` for a null argument. |
+| [`PropertyChangingObservable<T>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Observables/PropertyChangingObservable.cs) | Reads a property before each change. | Sealed class. Constructor: `INotifyPropertyChanging source`, `string propertyName`, `Func<INotifyPropertyChanging, T?> getter`. `Subscribe(IObserver<T>)` returns `IDisposable`. | Delivers the current value on subscription. Keeps repeated values, because the value has not changed when the event fires. A null or empty notification name matches every property. Hidden from IntelliSense. Throws `ArgumentNullException` for a null argument. |
+| [`PropertyObservable<T>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Observables/PropertyObservable.cs) | Reads a property on subscription and after each change. | Sealed class. Constructor: `INotifyPropertyChanged source`, `string propertyName`, `Func<INotifyPropertyChanged, T?> getter`, `bool distinctUntilChanged`. `Subscribe(IObserver<T>)` returns `IDisposable`. | With the flag true it drops a value equal to the last one. A null or empty notification name matches every property. Hidden from IntelliSense. Throws `ArgumentNullException` for a null argument. |
+| [`UnchangingPropertyObservable<T>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Observables/UnchangingPropertyObservable.cs) | Observes a property whose owner raises no notification. | Sealed class. Constructor: `T value`. `Subscribe(IObserver<T>)` returns `IDisposable`. | Delivers the value once and then nothing. Never completes, so a binding that observes it stays subscribed. Hidden from IntelliSense. Throws `ArgumentNullException` for a null observer. |
diff --git a/docs/documentation/binding/observing.md b/docs/documentation/binding/observing.md
new file mode 100644
index 00000000..07cc3e4d
--- /dev/null
+++ b/docs/documentation/binding/observing.md
@@ -0,0 +1,1999 @@
+---
+Order: 2
+---
+# Observing
+
+[Run the complete page example](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/observing/observing.csproj).
+
+A screen shows values that live on an object or deep inside one: the title of a to-do item, the login of an issue's assignee, the balance of the selected account. When one of those values changes, the screen has to change with it, and you do not want to poll for it.
+
+Observing solves this. You write a lambda that names a property or a chain of properties, and the library gives you a stream of values. A stream is an `IObservable<T>`: a source of values that arrive over time. You subscribe to the stream to receive its values. A subscription is an `IDisposable`, so you dispose it to stop receiving values. The [first page](index.md) walks through a first binding.
+
+An operator is a method that takes a stream and returns another stream, such as `Where` or `Select`. A notification is the way an object announces that a property changed, such as the `PropertyChanged` event of `INotifyPropertyChanged`. [Mechanisms](mechanisms.md) lists the notifications the library understands. A property path is a lambda that names one property or a chain of properties, such as `x => x.SelectedIssue!.Assignee!.Login`.
+
+The source generator reads each property path while your project builds and writes the observation code for it, so nothing looks up a property by name at run time. If the generator cannot read a call, [Unsafe twins and the runtime fallback](unsafe.md) covers the `Unsafe` overload that finds properties by reflection.
+
+## Observe one property
+
+**1. Call `WhenChanged` on the object.** The lambda `x => x.Title` names the property. The object must be a reference type that announces changes, for example through `PropertyChanged`.
+
+**2. Subscribe.** The stream delivers the current title as soon as you subscribe. `using` disposes the subscription at the end of the method. `CreateRegistrationTask` is a helper in the example that returns the sample to-do item.
+
+**3. Change the property.** The subscriber receives the new title right after the setter runs. The example below performs all three steps and prints every title the subscriber receives.
+
+```csharp
+var item = CreateRegistrationTask();
+
+using var subscription = item.WhenChanged(x => x.Title).Subscribe(Console.WriteLine);
+
+item.Title = RenamedTitle;
+```
+
+```text
+Renew car registration
+Renew car registration online
+```
+
+The stream delivered two values: the title when you subscribed, and the title after the change. `WhenChanged` delivers a value only when the property changes to a different value. Setting a property to the value it holds delivers nothing.
+
+## Choose an API
+
+Six APIs observe properties. They differ in when they deliver and in what they deliver.
+
+| API | Most properties | Delivers |
+| --- | --- | --- |
+| `WhenChanged` | sixteen | The value, a `PropertyValues` for several properties, or the result of a selector |
+| `WhenChanging` | sixteen | The same as `WhenChanged`, just before each change |
+| `WhenAnyValue` | sixteen | The same as `WhenChanged` |
+| `WhenAny` | twelve | The result of a selector that receives one observed change per property |
+| `WhenAnyObservable` | twelve | The values of the streams that the properties hold |
+| `WhenAnyDynamic` | twelve | The result of a selector that receives one observed change per chain |
+
+`WhenChanged`, `WhenChanging` and `WhenAnyValue` take one to sixteen properties. `WhenAny`, `WhenAnyObservable` and `WhenAnyDynamic` take one to twelve. A selector is a lambda that turns the observed values into one result. Every API except `WhenAnyObservable` delivers once when you subscribe and again after each change.
+
+Follow these habits with every API. Mark a lambda `static` when it captures nothing, so the compiler reuses one delegate. Name an unused selector parameter `_`. Dispose every subscription. Write the property path inline: the generator reads a lambda written at the call site, and a path held in a variable is a call it cannot read.
+
+A property path is a lambda that C# turns into an expression tree, and C# does not allow the null-propagating operator `?.` in such a lambda. Use a trailing `!` on a nullable link instead, as in `x => x.Assignee!`. The `!` only satisfies the compiler, the generator reads through it, and it changes nothing at run time. The generator does not read through parentheses, so write `x => x.A.B` and not `x => (x.A).B`.
+
+## Observe several properties
+
+Two or more properties deliver a `PropertyValues`. It holds one member per property, named `Property1`, `Property2` and so on, in the order of the lambdas. [Read several values at once](#read-several-values-at-once) covers it in detail.
+
+```csharp
+var item = CreateRegistrationTask();
+
+using var subscription = item.WhenChanged(x => x.Title, x => x.IsDone).Subscribe(static values => Console.WriteLine(values.Property2));
+
+item.IsDone = true;
+```
+
+```text
+False
+True
+```
+
+Add a selector as the last argument to turn the values into one result. The selector receives the values directly, in the order of the lambdas.
+
+```csharp
+var item = CreateRegistrationTask();
+
+using var subscription = item
+    .WhenChanged(x => x.Title, x => x.IsDone, static (title, isDone) => (isDone ? DoneMark : OpenMark) + title)
+    .Subscribe(Console.WriteLine);
+
+item.IsDone = true;
+```
+
+```text
+[ ] Renew car registration
+[x] Renew car registration
+```
+
+## Observe before a change
+
+`WhenChanging` delivers the values just before a change replaces them. It delivers the current values when you subscribe, and again before each change with the values the change is about to replace. The object must raise `INotifyPropertyChanging.PropertyChanging`. The example type `ChangingObject` is a base class whose setters raise `PropertyChanging` before they store a value and `PropertyChanged` after it. The analyzer reports RXUIBIND004 when a type cannot raise `PropertyChanging`. See [Setup](setup.md) for the analyzers.
+
+The example prints the title again after the setter runs, so you can compare the value the subscriber saw with the value the property holds.
+
+```csharp
+var item = CreateRegistrationTask();
+
+using var subscription = item.WhenChanging(x => x.Title).Subscribe(Console.WriteLine);
+
+item.Title = RenamedTitle;
+
+Console.WriteLine(item.Title);
+```
+
+```text
+Renew car registration
+Renew car registration
+Renew car registration online
+```
+
+The first line is the value at subscription. The second is the value before the change. The third is the value after the change.
+
+`WhenChanging` takes several properties in the same way as `WhenChanged`. Each emission holds the values before the change.
+
+```csharp
+var item = CreateRegistrationTask();
+
+using var subscription = item.WhenChanging(x => x.Title, x => x.IsDone).Subscribe(static values => Console.WriteLine(values.Property2));
+
+item.IsDone = true;
+
+Console.WriteLine(item.IsDone);
+```
+
+```text
+False
+False
+True
+```
+
+A selector turns the values before the change into one result. This one prints the status line the item had before its done flag changed.
+
+```csharp
+var item = CreateRegistrationTask();
+
+using var subscription = item
+    .WhenChanging(x => x.Title, x => x.IsDone, static (title, isDone) => $"{title} ({(isDone ? DoneText : OpenText)})")
+    .Subscribe(Console.WriteLine);
+
+item.IsDone = true;
+```
+
+```text
+Renew car registration (open)
+Renew car registration (open)
+```
+
+## Observe with WhenAnyValue
+
+`WhenAnyValue` takes the same lambdas as `WhenChanged` and delivers the same values after each change. The selector receives the values directly, and several properties deliver a `PropertyValues`.
+
+```csharp
+var item = CreateRegistrationTask();
+
+using var subscription = item.WhenAnyValue(x => x.Title, static title => title.Length).Subscribe(Console.WriteLine);
+
+item.Title = RenamedTitle;
+```
+
+```text
+22
+29
+```
+
+## Follow a path of properties
+
+A property path can pass through several objects. The board below has a selected issue, the issue has an assignee, and the assignee has a login. The observation follows every link. It delivers no value until every link has an object, and then it delivers the current login.
+
+```csharp
+var board = await OpenWebshopBoardAsync();
+var checkoutBug = FindIssue(board, CheckoutBugNumber);
+
+List<string> logins = [];
+
+using (board.WhenChanged(x => x.SelectedIssue!.Assignee!.Login).Subscribe(logins.Add))
+{
+    // Nothing is selected yet, so the path has no value to read.
+    Console.WriteLine(logins.Count);
+
+    board.SelectedIssue = checkoutBug;
+
+    checkoutBug.Assignee!.Login = TomasLogin;
+}
+
+Console.WriteLine(string.Join(", ", logins));
+```
+
+```text
+0
+priya-nair, tomas-berg
+```
+
+**The observation moves with the objects.** When an object in the middle of the path is replaced, the observation attaches to the new object. It lets go of the old one.
+
+```csharp
+var board = await OpenWebshopBoardAsync();
+var checkoutBug = FindIssue(board, CheckoutBugNumber);
+var previousAssignee = checkoutBug.Assignee!;
+
+board.SelectedIssue = checkoutBug;
+
+List<string> logins = [];
+
+using (board.WhenChanged(x => x.SelectedIssue!.Assignee!.Login).Subscribe(logins.Add))
+{
+    User newAssignee = new() { Login = TomasLogin };
+
+    checkoutBug.Assignee = newAssignee;
+
+    // The previous assignee no longer belongs to the path, so its changes are not observed.
+    previousAssignee.Login = MariaLogin;
+
+    newAssignee.Login = MariaLogin;
+}
+
+Console.WriteLine(string.Join(", ", logins));
+```
+
+```text
+priya-nair, tomas-berg, maria-santos
+```
+
+**Only a changed final value is delivered.** A change elsewhere on the path, or a change to the same value, delivers nothing.
+
+```csharp
+var board = await OpenWebshopBoardAsync();
+var checkoutBug = FindIssue(board, CheckoutBugNumber);
+
+board.SelectedIssue = checkoutBug;
+
+List<string> logins = [];
+
+using (board.WhenChanged(x => x.SelectedIssue!.Assignee!.Login).Subscribe(logins.Add))
+{
+    // The same login again.
+    checkoutBug.Assignee!.Login = PriyaLogin;
+
+    // A different property of the assignee.
+    checkoutBug.Assignee.DisplayName = "Priya N.";
+
+    // A different object with the same login.
+    checkoutBug.Assignee = new User { Login = PriyaLogin };
+
+    // A property of the issue that is not on the path.
+    checkoutBug.Title = "Checkout button fails on Safari";
+
+    checkoutBug.Assignee.Login = TomasLogin;
+}
+
+Console.WriteLine(string.Join(", ", logins));
+```
+
+```text
+priya-nair, tomas-berg
+```
+
+**A null in the middle delivers nothing.** When an object in the middle of the path is null, there is no final value to report. The observation waits for the next object.
+
+```csharp
+var board = await OpenWebshopBoardAsync();
+var giftCards = FindIssue(board, GiftCardNumber);
+
+List<string> logins = [];
+
+using (board.WhenChanged(x => x.SelectedIssue!.Assignee!.Login).Subscribe(logins.Add))
+{
+    // The issue has no assignee, so there is no login to report.
+    board.SelectedIssue = giftCards;
+
+    giftCards.Assignee = new User { Login = TomasLogin };
+
+    // Removing the assignee does not emit a null login either.
+    giftCards.Assignee = null;
+
+    giftCards.Assignee = new User { Login = MariaLogin };
+
+    board.SelectedIssue = null;
+}
+
+Console.WriteLine(string.Join(", ", logins));
+```
+
+```text
+tomas-berg, maria-santos
+```
+
+**A null final value is delivered.** When the path ends at the property that is null, every object on the path exists, so the null is a real value. It delivers nothing when no issue is selected.
+
+```csharp
+var board = await OpenWebshopBoardAsync();
+var giftCards = FindIssue(board, GiftCardNumber);
+User tomas = new() { Login = TomasLogin };
+
+// The trailing ! only satisfies the compiler: the emitted values include null.
+List<string> assignees = [];
+
+using (board.WhenChanged(x => x.SelectedIssue!.Assignee!).Subscribe(assignee => assignees.Add(assignee?.Login ?? Unassigned)))
+{
+    board.SelectedIssue = giftCards;
+
+    giftCards.Assignee = tomas;
+
+    giftCards.Assignee = null;
+
+    // With nothing selected there is no issue to read the assignee from.
+    board.SelectedIssue = null;
+}
+
+Console.WriteLine(string.Join(", ", assignees));
+```
+
+```text
+unassigned, tomas-berg, unassigned
+```
+
+**The null rules in one place.** A null link and a null value are different cases:
+
+- **A null link before the last property.** The observation holds no value for the path. It drops its subscription on the detached objects and waits for a new object. The subscriber receives nothing, not a null.
+- **A null last property.** Every object on the path exists, so the null is a real value and the subscriber receives it. Declare the subscriber's parameter as nullable, and use `!` on the lambda only to satisfy the compiler.
+
+**Every object on the path must announce changes.** A storage object in the example raises no notification. The path `x.SelectedObject!.Key` would stop following at that object, and the analyzer reports RXUIBIND010. The generated observation reads such a link once and never again, and it writes no message. It delivers the value it read and then nothing, and it never completes, so the subscription stays open. End the path at the selection and read the key when a value arrives. A change to the key alone is not reported, and selecting the object again reads the key it has then.
+
+```csharp
+var browser = await OpenMediaBucketAsync();
+var launchBanner = browser.Objects[LaunchBannerIndex];
+var teamOffsite = browser.Objects[TeamOffsiteIndex];
+
+List<string> keys = [];
+
+browser.SelectedObject = launchBanner;
+
+using (browser.WhenChanged(x => x.SelectedObject!).Subscribe(selected => keys.Add(selected.Key)))
+{
+    // A plain setter raises nothing, so the subscriber is not told.
+    launchBanner.Key = RenamedLaunchBannerKey;
+
+    browser.SelectedObject = teamOffsite;
+
+    // Selecting the object again reads the key it has now.
+    browser.SelectedObject = launchBanner;
+}
+
+Console.WriteLine(string.Join(", ", keys));
+```
+
+```text
+photos/2026/launch-banner.png, photos/2026/team-offsite.jpg, photos/2026/launch-banner-v2.png
+```
+
+A path can also start on a plain property and reach a property of a property. This path reads the money available in the account a draft transfer pays from.
+
+```csharp
+var transfer = await OpenTransferScreenAsync();
+var everyday = transfer.Accounts[EverydayAccountIndex];
+var savings = transfer.Accounts[SavingsAccountIndex];
+
+List<decimal> available = [];
+
+using (transfer.WhenChanged(x => x.Draft.Source!.AvailableBalance).Subscribe(available.Add))
+{
+    transfer.Draft.Source = everyday;
+
+    everyday.Balance = EverydayBalanceAfterRent;
+
+    transfer.Draft.Source = savings;
+
+    // The everyday account is no longer the source, so its balance is no longer observed.
+    everyday.Balance = EverydayBalanceAfterBills;
+
+    savings.Balance = SavingsBalanceAfterWithdrawal;
+
+    Console.WriteLine(string.Join(", ", available));
+}
+```
+
+```text
+2950.75, 1750.75, 15230.00, 15000
+```
+
+## Read the sender with WhenAny
+
+`WhenAny` hands its selector an observed change for each property instead of the bare value. An observed change carries the object that changed (`Sender`), the property value (`Value`) and the property expression (`Expression`). `WhenAny` takes one to twelve properties and always takes a selector. An observation that the generator wrote has no expression tree to report, so `Expression` is `null`.
+
+```csharp
+var item = new TodoItem { Id = 1, Title = ReviewPrTitle };
+
+using var subscription = item.WhenAny(x => x.Title, static change => change)
+    .Subscribe(static change => Console.WriteLine($"Item {change.Sender.Id} is now '{change.Value}'"));
+
+item.Title = RenamedTitle;
+```
+
+```text
+Item 1 is now 'Review PR'
+Item 1 is now 'Review PR 204'
+```
+
+The next example prints whether the expression is `null`.
+
+```csharp
+var item = new TodoItem { Id = 1, Title = ReviewPrTitle };
+
+using var subscription = item.WhenAny(x => x.Title, static change => change)
+    .Subscribe(static change => Console.WriteLine(change.Expression is null));
+```
+
+```text
+True
+```
+
+A selector can also read the value alone. This one turns the title into its length, as a character counter does.
+
+```csharp
+var item = CreateRegistrationTask();
+
+using var subscription = item.WhenAny(x => x.Title, static title => title.Value.Length).Subscribe(Console.WriteLine);
+
+item.Title = RenamedTitle;
+```
+
+```text
+22
+29
+```
+
+With several properties, the selector receives one observed change per property, in order. Read `Value` from each one.
+
+```csharp
+var item = CreateRegistrationTask();
+
+using var subscription = item
+    .WhenAny(x => x.Title, x => x.IsDone, x => x.Priority, static (_, isDone, priority) => isDone.Value ? TodoPriority.Low : priority.Value)
+    .Subscribe(static priority => Console.WriteLine(priority));
+
+item.Priority = TodoPriority.High;
+item.IsDone = true;
+```
+
+```text
+Normal
+High
+Low
+```
+
+**A selector that throws ends the stream with an error.** `Catch` can replace the error with a value, but the stream ends after it, so later changes are never delivered.
+
+```csharp
+var server = InMemoryGitHubServer.CreateSeeded();
+IssueSearchViewModel viewModel = new(server, Webshop) { SearchTerm = FirstIssueNumber };
+
+using var subscription = viewModel
+    .WhenAny(x => x.SearchTerm, static term => int.Parse(term.Value, CultureInfo.InvariantCulture))
+    .Catch<int, FormatException>(static _ => Signal.Return(NotANumber))
+    .Subscribe(Console.WriteLine);
+
+viewModel.SearchTerm = SecondIssueNumber;
+viewModel.SearchTerm = "abc";
+
+// The pipeline has ended, so this number is never delivered.
+viewModel.SearchTerm = ThirdIssueNumber;
+```
+
+```text
+100
+101
+-1
+```
+
+Handle the failure inside the selector when the stream has to keep going.
+
+```csharp
+var server = InMemoryGitHubServer.CreateSeeded();
+IssueSearchViewModel viewModel = new(server, Webshop) { SearchTerm = FirstIssueNumber };
+
+using var subscription = viewModel
+    .WhenAny(x => x.SearchTerm, static term => int.TryParse(term.Value, CultureInfo.InvariantCulture, out var number) ? number : NotANumber)
+    .Subscribe(Console.WriteLine);
+
+viewModel.SearchTerm = SecondIssueNumber;
+viewModel.SearchTerm = "abc";
+viewModel.SearchTerm = ThirdIssueNumber;
+```
+
+```text
+100
+101
+-1
+102
+```
+
+## Work with an observed change
+
+`ObservedChange<TSender, TValue>` is the class behind `IObservedChange<TSender, TValue>`. The generator creates one for each notification, and you can create one yourself with a sender, an expression and a value. The expression may be `null`.
+
+```csharp
+var item = new TodoItem { Id = 1, Title = ReviewPrTitle };
+Expression<Func<TodoItem, string>> expression = x => x.Title;
+
+var change = new ObservedChange<TodoItem, string>(item, expression.Body, item.Title);
+
+Console.WriteLine(change.Sender.Title);
+Console.WriteLine(change.Expression);
+Console.WriteLine(change.Value);
+```
+
+```text
+Review PR
+x.Title
+Review PR
+```
+
+Pass `null` for the expression when the observation needs no expression tree.
+
+```csharp
+var item = new TodoItem { Id = 1, Title = ReviewPrTitle };
+
+var change = new ObservedChange<TodoItem, string>(item, null, item.Title);
+
+Console.WriteLine(change.Sender.Title);
+Console.WriteLine(change.Value);
+Console.WriteLine(change.Expression is null);
+```
+
+```text
+Review PR
+Review PR
+True
+```
+
+The helpers below read the expression, so they need one. They live in the `ReactiveUI.Binding.ObservableForProperty` namespace. Each reads properties by reflection and carries `RequiresUnreferencedCode`, so none is safe to trim. Read `change.Value` when you can.
+
+**`GetPropertyName` names the property.** It joins every step of the path with dots.
+
+```csharp
+var issue = new Issue { Number = CheckoutNumber, Title = CheckoutTitle, Assignee = new User { Login = "priya-nair" } };
+Expression<Func<Issue, string>> title = x => x.Title;
+Expression<Func<Issue, string>> assigneeLogin = x => x.Assignee!.Login;
+
+ObservedChange<Issue, string> titleChange = new(issue, title.Body, issue.Title);
+ObservedChange<Issue, string> loginChange = new(issue, assigneeLogin.Body, issue.Assignee!.Login);
+
+Console.WriteLine(titleChange.GetPropertyName());
+Console.WriteLine(loginChange.GetPropertyName());
+```
+
+```text
+Title
+Assignee.Login
+```
+
+**`GetValue` reads the value.** It returns the value the change carries. When the change carries the default value, it reads the value from the sender through the expression.
+
+```csharp
+var item = new TodoItem { Id = 1, Title = ReviewPrTitle };
+Expression<Func<TodoItem, string>> expression = x => x.Title;
+
+ObservedChange<TodoItem, string> carried = new(item, expression.Body, RenamedTitle);
+ObservedChange<TodoItem, string> empty = new(item, expression.Body, default!);
+
+Console.WriteLine(carried.GetValue());
+Console.WriteLine(empty.GetValue());
+```
+
+```text
+Review PR 204
+Review PR
+```
+
+When an object in the middle of the path is null, `GetValue` throws an `InvalidOperationException` and `GetValueOrDefault` returns the default.
+
+```csharp
+var issue = new Issue { Number = CheckoutNumber, Title = CheckoutTitle, Assignee = null };
+Expression<Func<Issue, string>> assigneeLogin = x => x.Assignee!.Login;
+
+ObservedChange<Issue, string> change = new(issue, assigneeLogin.Body, default!);
+
+Console.WriteLine(change.GetValueOrDefault() is null);
+
+try
+{
+    Console.WriteLine(change.GetValue());
+}
+catch (InvalidOperationException ex)
+{
+    Console.WriteLine(ex.Message);
+}
+```
+
+```text
+True
+One of the properties in the expression 'Assignee.Login' was null
+```
+
+**`Value()` turns a stream of changes into a stream of values.** It applies the same read to each change. 
+
+```csharp
+var item = new TodoItem { Id = 1, Title = ReviewPrTitle };
+
+using var subscription = item.WhenAny(x => x.Title, static change => change)
+    .Value()
+    .Subscribe(Console.WriteLine);
+
+item.Title = RenamedTitle;
+```
+
+```text
+Review PR
+Review PR 204
+```
+
+## Read several values at once
+
+An emission with two to sixteen properties is a `PropertyValues<T1, ..., T16>` with members `Property1` to `Property16`. It is a read-only record struct, so it supports deconstruction, value equality, `with` copies and a readable `ToString`.
+
+The examples read the first emission with `FirstAsync()`, which returns a `Task` that completes with the first value. Because the stream delivers the current values on subscription, that value is the current state.
+
+**Read the members and deconstruct.** Deconstruction returns one variable per member.
+
+```csharp
+var item = CreateRegistrationTask();
+
+var values = await item.WhenChanged(x => x.Title, x => x.IsDone, x => x.Priority).FirstAsync();
+
+Console.WriteLine(values.Property1);
+Console.WriteLine(values.Property2);
+Console.WriteLine(values.Property3);
+
+var (title, isDone, priority) = values;
+
+Console.WriteLine(values.Equals(new(title, isDone, priority)));
+```
+
+```text
+Renew car registration
+False
+Normal
+True
+```
+
+**Read in a subscription.** A subscriber reads the members it needs from each emission.
+
+```csharp
+var item = CreateRegistrationTask();
+List<string> lines = [];
+
+using (item
+    .WhenChanged(x => x.Title, x => x.IsDone, x => x.Priority)
+    .Subscribe(values => lines.Add($"{values.Property1} ({values.Property3}, done: {values.Property2})")))
+{
+    item.Priority = TodoPriority.High;
+}
+
+Console.WriteLine(string.Join(", ", lines));
+```
+
+```text
+Renew car registration (Normal, done: False), Renew car registration (High, done: False)
+```
+
+**Compare emissions.** Two emissions are equal when every member is equal, and equal emissions have the same hash code.
+
+```csharp
+var first = CreateRegistrationTask();
+var second = CreateRegistrationTask();
+
+var left = await first.WhenChanged(x => x.Title, x => x.IsDone).FirstAsync();
+var right = await second.WhenChanged(x => x.Title, x => x.IsDone).FirstAsync();
+var boxed = (object)right;
+
+Console.WriteLine(left == right);
+Console.WriteLine(left != right);
+Console.WriteLine(left.Equals(right));
+Console.WriteLine(left.Equals(boxed));
+Console.WriteLine(left.GetHashCode() == right.GetHashCode());
+
+second.IsDone = true;
+var finished = await second.WhenChanged(x => x.Title, x => x.IsDone).FirstAsync();
+
+Console.WriteLine(left == finished);
+```
+
+```text
+True
+False
+True
+True
+True
+False
+```
+
+**Copy with one member replaced.** `with` leaves the original unchanged.
+
+```csharp
+var item = CreateRegistrationTask();
+
+var original = await item.WhenChanged(x => x.Title, x => x.IsDone).FirstAsync();
+var finished = original with { Property2 = true };
+
+Console.WriteLine(original.Property2);
+Console.WriteLine(finished.Property2);
+```
+
+```text
+False
+True
+```
+
+**Print an emission.** `ToString` names each member.
+
+```csharp
+var item = CreateRegistrationTask();
+
+var values = await item.WhenChanged(x => x.Title, x => x.IsDone).FirstAsync();
+
+Console.WriteLine($"Emission: {values}.");
+```
+
+```text
+Emission: PropertyValues { Property1 = Renew car registration, Property2 = False }.
+```
+
+An emission holds up to sixteen properties and follows the same pattern at every size: `Property1` to `Property16`, deconstruction into one variable each, and equality over every member. `PropertyValuesExamples` in the example project has one method for each size from two to sixteen.
+
+`PropertyValuesComparisonExamples` compares and prints emissions of each size. The first prints an emission of two properties.
+
+```csharp
+var form = CreateTransferForm();
+
+var values = await form.WhenChanged(x => x.Amount, x => x.Reference).FirstAsync();
+
+var text = values.ToString();
+
+Console.WriteLine($"Emission: {text}.");
+```
+
+```text
+Emission: PropertyValues { Property1 = 250, Property2 = Rent March }.
+```
+
+Each larger size copies the emission, changes `Property1`, and checks equality, the hash code and the text. This proves that an emission behaves the same at every size. The first example below uses three properties.
+
+```csharp
+var form = CreateTransferForm();
+
+var values = await form
+    .WhenChanged(
+        x => x.Amount,
+        x => x.Reference,
+        x => x.SourceId)
+    .FirstAsync();
+var copy = values with { };
+var edited = values with { Property1 = default };
+
+Console.WriteLine(values == copy);
+Console.WriteLine(values != edited);
+Console.WriteLine(values.Equals((object)copy));
+Console.WriteLine(values.GetHashCode() == copy.GetHashCode());
+Console.WriteLine(values.ToString().Contains("Property3 = "));
+```
+
+```text
+True
+True
+True
+True
+True
+```
+
+The larger sizes run the same five checks on more properties, up to sixteen.
+
+## Follow a property that holds a stream
+
+Some properties hold a stream. The issue feed in the example has one property for each kind of activity, and every property is replaced when the user selects another repository. `WhenAnyObservable` subscribes to the stream a property holds. When the property changes, it drops the old stream and follows the new one.
+
+```csharp
+using RepositoryChannels webshop = new(_webshop);
+RepositoryFeedViewModel feed = new();
+feed.Follow(webshop);
+
+using var subscription = feed.WhenAnyObservable(x => x.IssueOpened).Subscribe(Console.WriteLine);
+
+webshop.IssueOpened.OnNext(IssueOpenedEvent);
+```
+
+```text
+#101 opened: Checkout button unresponsive
+```
+
+Selecting another repository replaces the stream. The first repository loses its subscriber, and the second gains one.
+
+```csharp
+using RepositoryChannels webshop = new(_webshop);
+using RepositoryChannels mobileApp = new(_mobileApp);
+RepositoryFeedViewModel feed = new();
+feed.Follow(webshop);
+
+using var subscription = feed.WhenAnyObservable(x => x.IssueOpened).Subscribe(Console.WriteLine);
+
+Console.WriteLine(webshop.IssueOpened.HasObservers);
+
+feed.Follow(mobileApp);
+
+Console.WriteLine(webshop.IssueOpened.HasObservers);
+Console.WriteLine(mobileApp.IssueOpened.HasObservers);
+
+webshop.IssueOpened.OnNext(StaleEvent);
+mobileApp.IssueOpened.OnNext(MobileAppEvent);
+```
+
+```text
+True
+False
+True
+#7 opened: App crashes on start
+```
+
+A property that holds no stream delivers nothing and keeps no subscription.
+
+```csharp
+using RepositoryChannels webshop = new(_webshop);
+RepositoryFeedViewModel feed = new();
+feed.Follow(webshop);
+
+using var subscription = feed.WhenAnyObservable(x => x.IssueOpened).Subscribe(Console.WriteLine);
+
+feed.Unfollow();
+
+Console.WriteLine(webshop.IssueOpened.HasObservers);
+
+webshop.IssueOpened.OnNext(StaleEvent);
+
+feed.Follow(webshop);
+webshop.IssueOpened.OnNext(IssueOpenedEvent);
+```
+
+```text
+False
+#101 opened: Checkout button unresponsive
+```
+
+**Name several properties to merge their streams.** `WhenAnyObservable` takes one to twelve properties that hold streams of the same element type. The result delivers the values of all of them in the order they arrive.
+
+```csharp
+using RepositoryChannels webshop = new(_webshop);
+RepositoryFeedViewModel feed = new();
+feed.Follow(webshop);
+
+using var subscription = feed
+    .WhenAnyObservable(x => x.IssueOpened, x => x.IssueClosed)
+    .Subscribe(Console.WriteLine);
+
+webshop.IssueClosed.OnNext(IssueClosedEvent);
+webshop.IssueOpened.OnNext(IssueOpenedEvent);
+```
+
+```text
+#98 closed: Cart total rounds down
+#101 opened: Checkout button unresponsive
+```
+
+Only the streams you name receive a subscriber. The repository in the example has more streams than the two named here.
+
+```csharp
+using RepositoryChannels webshop = new(_webshop);
+RepositoryFeedViewModel feed = new();
+feed.Follow(webshop);
+
+using var subscription = feed.WhenAnyObservable(x => x.IssueOpened, x => x.ReleasePublished).Subscribe(Console.WriteLine);
+
+Console.WriteLine(webshop.SubscribedStreamCount);
+```
+
+```text
+2
+```
+
+The twelve-stream form merges the issue, comment, milestone, pull request, review and release streams in one call. `MergeThreeStreams` to `MergeTwelveStreams` in the example project add one property at a time.
+
+**Add a selector to combine the latest values.** With a selector as the last argument, the result delivers the selector's result each time one stream delivers. It starts once every stream has delivered a value. `PublishNotice` sends one announcement on every stream, so each stream has a value before the closing event arrives.
+
+```csharp
+using RepositoryChannels webshop = new(_webshop);
+RepositoryFeedViewModel feed = new();
+feed.Follow(webshop);
+
+using var subscription = feed
+    .WhenAnyObservable(x => x.IssueOpened, x => x.IssueClosed, static (first, last) => $"{first} / {last}")
+    .Subscribe(Console.WriteLine);
+
+webshop.PublishNotice(MaintenanceNotice);
+webshop.IssueClosed.OnNext(IssueClosedEvent);
+```
+
+```text
+Maintenance starts at 22:00 UTC / Maintenance starts at 22:00 UTC
+Maintenance starts at 22:00 UTC / #98 closed: Cart total rounds down
+```
+
+## Shape a stream of property changes with Primitives operators
+
+The streams that observation returns are ordinary `IObservable<T>` streams, so any operator works on them. The operators come from [ReactiveUI.Primitives](../primitives/index.md), the package that `ReactiveUI.Binding` builds on. Add `using ReactiveUI.Primitives;` to use them.
+
+Primitives gives some operators two names. The examples use `Throttle`, `Sample`, `Scan` and `Window`. [Time operators](../primitives/time.md) and [aggregation](../primitives/aggregation.md) list both names of each.
+
+Two ideas recur in the examples:
+
+- **The first value is the current value.** `WhenChanged` delivers the current value when you subscribe. `Skip(1)` drops it when you want changes only.
+- **A time operator takes a sequencer.** A sequencer decides when and where work runs. The examples pass a `VirtualClock`, a sequencer that moves only when you call `AdvanceBy`, so each example runs at once and prints the same output every time. Leave the argument out and the operator measures time on a thread pool timer, and delivers on that timer's thread. `WitnessOn` below moves values to a sequencer such as the UI thread. [Scheduling](../primitives/scheduling.md) covers sequencers.
+
+To share one subscription among several subscribers, or to keep the latest value for a subscriber that joins late, use the sharing operators in [Sharing](../primitives/sharing.md). To defer building a stream until someone subscribes, use `Lazy` in [Creation factories](../primitives/creation-factories.md).
+
+### Build a search box
+
+A search box is the classic shaped stream. The user types, and a search should run once for each settled term. The view model in the example chains five operators on the term.
+
+- `Throttle` delivers a term only after the user stops typing for the quiet period.
+- `Select` trims each term.
+- `DistinctUntilChanged` drops a term that equals the term before it.
+- `Where` drops a blank term.
+- `SwitchMap` starts a search for each term and drops the search that is waiting when a newer term arrives. A slow response to an older term cannot overwrite the results of a newer one.
+
+The method below is the whole pipeline. It returns the subscription, so the caller can dispose it to stop the searching.
+
+```csharp
+public IDisposable StartSearching(ISequencer sequencer, TimeSpan quietPeriod) =>
+    this.WhenAnyValue(x => x.SearchTerm)
+        .Throttle(quietPeriod, sequencer)
+        .Select(static term => term.Trim())
+        .DistinctUntilChanged()
+        .Where(static term => term.Length > 0)
+        .SwitchMap(BeginSearch)
+        .Subscribe(EndSearch);
+```
+
+The first three operators on their own show what the pipeline does to typed text. Padding and blank input start no search, and the same term twice starts one search.
+
+```csharp
+const string PaddedCheckout = "  checkout ";
+
+var server = InMemoryGitHubServer.CreateSeeded();
+IssueSearchViewModel viewModel = new(server, Webshop);
+
+using var subscription = viewModel.WhenChanged(x => x.SearchTerm)
+    .Select(static term => term.Trim())
+    .DistinctUntilChanged()
+    .Where(static term => term.Length > 0)
+    .Subscribe(Console.WriteLine);
+
+viewModel.SearchTerm = PaddedCheckout;
+viewModel.SearchTerm = CheckoutTerm;
+viewModel.SearchTerm = "   ";
+viewModel.SearchTerm = GiftTerm;
+```
+
+```text
+checkout
+gift
+```
+
+`Throttle` needs time to pass. This example uses a `VirtualClock`, so every key press restarts the wait and only a pause delivers a term.
+
+```csharp
+VirtualClock clock = new();
+var server = InMemoryGitHubServer.CreateSeeded();
+IssueSearchViewModel viewModel = new(server, Webshop);
+
+using var subscription = viewModel.WhenAnyValue(x => x.SearchTerm)
+    .Throttle(_quietPeriod, clock)
+    .Subscribe(Console.WriteLine);
+
+viewModel.SearchTerm = "c";
+clock.AdvanceBy(_keyGap);
+viewModel.SearchTerm = "cr";
+clock.AdvanceBy(_keyGap);
+viewModel.SearchTerm = CraTerm;
+
+// Every key press restarts the wait, so nothing has settled yet.
+clock.AdvanceBy(_keyGap);
+Console.WriteLine("Still typing");
+
+clock.AdvanceBy(_quietPeriod);
+
+viewModel.SearchTerm = CrashTerm;
+clock.AdvanceBy(_quietPeriod);
+```
+
+```text
+Still typing
+cra
+crash
+```
+
+The whole view model searches once for each settled term and shows the matches. The request counter shows that a repeated term sends no request. The example uses the real clock, so it waits a short time for each search to finish.
+
+```csharp
+var server = await CreateSignedInServerAsync();
+IssueSearchViewModel viewModel = new(server, Webshop);
+
+using var subscription = viewModel.StartSearching(Sequencer.Default, _quietPeriod);
+
+var quotaAtStart = server.RateLimitRemaining;
+
+viewModel.SearchTerm = "  checkout ";
+await Task.Delay(_settle);
+
+Console.WriteLine(string.Join(", ", TitlesOf(viewModel.Results)));
+Console.WriteLine(viewModel.IsSearching);
+Console.WriteLine(quotaAtStart - server.RateLimitRemaining);
+
+// The same term without its padding trims to the term already searched, so no request goes out.
+viewModel.SearchTerm = CheckoutTerm;
+await Task.Delay(_settle);
+Console.WriteLine(quotaAtStart - server.RateLimitRemaining);
+
+viewModel.SearchTerm = "GIFT";
+await Task.Delay(_settle);
+
+Console.WriteLine(string.Join(", ", TitlesOf(viewModel.Results)));
+Console.WriteLine(quotaAtStart - server.RateLimitRemaining);
+```
+
+```text
+Checkout button unresponsive on Safari
+False
+1
+1
+Add gift-card support
+2
+```
+
+`SwitchMap` protects the results from a slow response. The first search below takes longer than the second, and its response is dropped when it arrives.
+
+```csharp
+var server = await CreateSignedInServerAsync();
+IssueSearchViewModel viewModel = new(server, Webshop);
+
+using var subscription = viewModel.StartSearching(Sequencer.Default, _quietPeriod);
+
+// The first response takes longer than the second.
+server.Latency = _slowResponse;
+viewModel.SearchTerm = CheckoutTerm;
+await Task.Delay(_settle);
+
+server.Latency = TimeSpan.Zero;
+viewModel.SearchTerm = GiftTerm;
+await Task.Delay(_settle);
+
+Console.WriteLine(string.Join(", ", TitlesOf(viewModel.Results)));
+Console.WriteLine(viewModel.IsSearching);
+
+// The response for "checkout" arrives now and is dropped.
+await Task.Delay(_slowResponse);
+
+Console.WriteLine(string.Join(", ", TitlesOf(viewModel.Results)));
+```
+
+```text
+Add gift-card support
+False
+Add gift-card support
+```
+
+The same pause works on a control. This example copies the amount box into the draft once the customer stops typing, without a two-way binding.
+
+```csharp
+VirtualClock clock = new();
+TransferViewModel screen = new(new InMemoryBankingBackend());
+TransferView view = new() { ViewModel = screen };
+
+using var subscription = view.AmountTextBox.WhenChanged(x => x.Text)
+    .Where(static text => !string.IsNullOrEmpty(text))
+    .Throttle(_quietPeriod, clock)
+    .Subscribe(text => screen.Draft.Amount = decimal.Parse(text, CultureInfo.InvariantCulture));
+
+view.AmountTextBox.Text = "1";
+clock.AdvanceBy(_keyGap);
+view.AmountTextBox.Text = "12";
+clock.AdvanceBy(_keyGap);
+view.AmountTextBox.Text = "125";
+
+Console.WriteLine(screen.Draft.Amount);
+
+clock.AdvanceBy(_quietPeriod);
+
+Console.WriteLine(screen.Draft.Amount);
+```
+
+```text
+0
+125
+```
+
+`BindSearchStateToView` in the example project binds the busy flag and the results to a view with the APIs that [Bindings](bindings.md) covers.
+
+### Slow a fast stream
+
+`Throttle` waits for a quiet moment. It delivers a value only after no newer value has arrived for the period you give, so every edit restarts the wait. The notes below save only after the user stops typing for 300 ms.
+
+```csharp
+VirtualClock clock = new();
+TodoItem item = new();
+
+using var subscription = item.WhenChanged(x => x.Notes)
+    .Skip(1)
+    .Throttle(_quietPeriod, clock)
+    .Subscribe(static notes => Console.WriteLine($"Saved: {notes}"));
+
+item.Notes = FirstNote;
+clock.AdvanceBy(_keyGap);
+item.Notes = SecondNote;
+clock.AdvanceBy(_keyGap);
+item.Notes = ThirdNote;
+clock.AdvanceBy(_quietPeriod);
+```
+
+```text
+Saved: Bring the plates, the receipt and a pen
+```
+
+`Sample` delivers the newest value on a fixed beat instead. Use it for a slider that redraws a preview while the user drags. A quiet period sends nothing.
+
+```csharp
+VirtualClock clock = new();
+TransferDraft draft = new();
+
+using var subscription = draft.WhenChanged(x => x.Amount)
+    .Skip(1)
+    .Sample(_sampleInterval, clock)
+    .Subscribe(static amount => Console.WriteLine($"Preview {amount}"));
+
+draft.Amount = FirstAmount;
+draft.Amount = SecondAmount;
+clock.AdvanceBy(_sampleInterval);
+draft.Amount = ThirdAmount;
+draft.Amount = LastAmount;
+clock.AdvanceBy(_sampleInterval);
+clock.AdvanceBy(_sampleInterval);
+```
+
+```text
+Preview 20
+Preview 40
+```
+
+### Collect changes into lists with Buffer
+
+`Buffer` gathers values into lists. Give it a count, and it delivers a list each time that many values have arrived. The fourth reference below waits for a list that is not full.
+
+```csharp
+TransferDraft draft = new();
+
+using var subscription = draft.WhenChanged(x => x.Reference)
+    .Skip(1)
+    .Buffer(EditsPerList)
+    .Subscribe(static edits => Console.WriteLine(string.Join(Separator, edits)));
+
+draft.Reference = FirstReference;
+draft.Reference = SecondReference;
+draft.Reference = ThirdReference;
+draft.Reference = FourthReference;
+```
+
+```text
+Rent | Rent March | Rent March 2026
+```
+
+A second count is the step: it starts a new list after that many values, so lists overlap. With a step of one, each list holds the last three edits.
+
+```csharp
+TransferDraft draft = new();
+
+using var subscription = draft.WhenChanged(x => x.Reference)
+    .Skip(1)
+    .Buffer(EditsPerList, EditsBetweenLists)
+    .Subscribe(static edits => Console.WriteLine(string.Join(Separator, edits)));
+
+draft.Reference = FirstReference;
+draft.Reference = SecondReference;
+draft.Reference = ThirdReference;
+draft.Reference = FourthReference;
+```
+
+```text
+Rent | Rent March | Rent March 2026
+Rent March | Rent March 2026 | Rent April 2026
+```
+
+A time period delivers one list for each period. The sequencer measures the period, so the example moves the clock to end each list.
+
+```csharp
+VirtualClock clock = new();
+TransferDraft draft = new();
+
+using var subscription = draft.WhenChanged(x => x.Reference)
+    .Skip(1)
+    .Buffer(_bufferLength, clock)
+    .Subscribe(static edits => Console.WriteLine($"Batch of {edits.Count}: {string.Join(Separator, edits)}"));
+
+draft.Reference = FirstReference;
+draft.Reference = SecondReference;
+clock.AdvanceBy(_bufferLength);
+draft.Reference = ThirdReference;
+clock.AdvanceBy(_bufferLength);
+```
+
+```text
+Batch of 2: Rent | Rent March
+Batch of 1: Rent March 2026
+```
+
+### Cut a stream into slices
+
+`Slice` cuts a stream into slices. Each slice is itself a stream that delivers the values of that slice. `Window` is the same operator under another name. Because a slice is a stream, you decide what to do with it: `ToList` collects it into a list, and `Count` counts it. `SelectMany` flattens the result back into one stream.
+
+A slice can end on a count, on time, on another stream, or on a mix of them.
+
+| Call | The slice ends |
+| --- | --- |
+| `Slice(count)` | After that many values |
+| `Slice(count, skip)` | After `count` values; a new slice starts every `skip` values, so slices overlap or leave gaps |
+| `Slice(timeSpan, sequencer)` | After the time span |
+| `Slice(timeSpan, timeShift, sequencer)` | After the time span; a new slice starts every `timeShift` |
+| `Slice(timeSpan, count, sequencer)` | After the time span or the count, whichever comes first |
+| `Slice(boundaries)` | Each time the boundary stream delivers |
+| `Slice(closingSelector)` | When the stream that the method returns delivers |
+| `Slice(openings, closingSelector)` | A slice opens for each opening value and ends with the stream the method returns for it |
+
+The examples below show each form in turn.
+
+**Slice by count.** Three edits make a slice. The fourth edit waits in a slice that is not full, so it is not delivered.
+
+```csharp
+TodoItem item = new() { Title = DraftTitle };
+
+using var subscription = item.WhenChanged(x => x.Title)
+    .Skip(1)
+    .Slice(EditsPerSlice)
+    .SelectMany(static slice => slice.ToList())
+    .Subscribe(static edits => Console.WriteLine(string.Join(Separator, edits)));
+
+item.Title = FirstTitle;
+item.Title = SecondTitle;
+item.Title = ThirdTitle;
+item.Title = FourthTitle;
+```
+
+```text
+Renew, Renew car, Renew car registration
+```
+
+**Slice by count with a step.** Slices of two that start after every edit pair each edit with the one before it. This example keeps the current value, so the first pair holds the title the task started with.
+
+```csharp
+TodoItem item = new() { Title = DraftTitle };
+
+using var subscription = item.WhenChanged(x => x.Title)
+    .Slice(EditsPerPair, EditsBetweenSlices)
+    .SelectMany(static slice => slice.ToList())
+    .Subscribe(static pair => Console.WriteLine(string.Join(" -> ", pair)));
+
+item.Title = FirstTitle;
+item.Title = SecondTitle;
+item.Title = ThirdTitle;
+```
+
+```text
+Draft -> Renew
+Renew -> Renew car
+Renew car -> Renew car registration
+```
+
+**Slice by time.** A time span ends each slice after that long. The sequencer measures the span, so the example moves the clock to end each slice.
+
+```csharp
+VirtualClock clock = new();
+TransferDraft draft = new();
+
+using var subscription = draft.WhenChanged(x => x.Amount)
+    .Skip(1)
+    .Slice(_sliceLength, clock)
+    .SelectMany(static slice => slice.ToList())
+    .Subscribe(static amounts => Console.WriteLine(string.Join(Separator, amounts)));
+
+draft.Amount = FirstAmount;
+clock.AdvanceBy(_editGap);
+draft.Amount = SecondAmount;
+clock.AdvanceBy(_sliceLength);
+draft.Amount = ThirdAmount;
+clock.AdvanceBy(_sliceLength);
+```
+
+```text
+10, 20
+30
+```
+
+**Slice by time or count.** A slice ends after the time span or after the count, whichever comes first. The first slice below fills up after three edits, and the fourth edit waits for the time span.
+
+```csharp
+VirtualClock clock = new();
+TransferDraft draft = new();
+
+using var subscription = draft.WhenChanged(x => x.Amount)
+    .Skip(1)
+    .Slice(_sliceLength, EditsPerSlice, clock)
+    .SelectMany(static slice => slice.ToList())
+    .Subscribe(static amounts => Console.WriteLine(string.Join(Separator, amounts)));
+
+draft.Amount = FirstAmount;
+draft.Amount = SecondAmount;
+draft.Amount = ThirdAmount;
+draft.Amount = FirstAmount + ThirdAmount;
+clock.AdvanceBy(_sliceLength);
+```
+
+```text
+10, 20, 30
+40
+```
+
+**Slice with overlapping time.** A second time span sets how often a new slice starts. Each slice lasts the first span, so slices overlap and an edit can land in two of them.
+
+```csharp
+VirtualClock clock = new();
+TransferDraft draft = new();
+
+using var subscription = draft.WhenChanged(x => x.Amount)
+    .Skip(1)
+    .Slice(_sliceLength, _sliceShift, clock)
+    .SelectMany(static slice => slice.ToList())
+    .Subscribe(static amounts => Console.WriteLine(string.Join(Separator, amounts)));
+
+clock.AdvanceBy(_editGap);
+draft.Amount = FirstAmount;
+clock.AdvanceBy(_editGap);
+draft.Amount = SecondAmount;
+clock.AdvanceBy(_sliceLength);
+```
+
+```text
+10, 20
+20
+```
+
+**Slice on another stream.** Give `Slice` a stream of boundaries. Each time it delivers, the current slice ends and the next one starts. `Signal.Every` delivers on a fixed period, like an autosave timer.
+
+```csharp
+VirtualClock clock = new();
+TodoItem item = new();
+
+using var subscription = item.WhenChanged(x => x.Notes)
+    .Skip(1)
+    .Slice(Signal.Every(_autosaveInterval, clock))
+    .SelectMany(static slice => slice.ToList())
+    .Subscribe(static notes => Console.WriteLine(string.Join(Separator, notes)));
+
+item.Notes = "Bring the old plates";
+item.Notes = "Bring the old plates and the receipt";
+clock.AdvanceBy(_autosaveInterval);
+item.Notes = "Bring the plates, the receipt and a pen";
+clock.AdvanceBy(_autosaveInterval);
+```
+
+```text
+Bring the old plates, Bring the old plates and the receipt
+Bring the plates, the receipt and a pen
+```
+
+**Slice until a stream fires.** Give `Slice` a method that returns the closing stream. It ends each slice with the stream it returns and starts the next slice. Here a tick of the checkbox ends a slice.
+
+```csharp
+TodoItem item = new() { Title = DraftTitle };
+
+using var subscription = item.WhenChanged(x => x.Title)
+    .Skip(1)
+    .Slice(() => item.WhenChanged(x => x.IsDone).Skip(1))
+    .SelectMany(static slice => slice.ToList())
+    .Subscribe(static titles => Console.WriteLine(string.Join(Separator, titles)));
+
+item.Title = FirstTitle;
+item.Title = SecondTitle;
+item.IsDone = true;
+item.Title = ThirdTitle;
+item.IsDone = false;
+```
+
+```text
+Renew, Renew car
+Renew car registration
+```
+
+**Slice while a condition holds.** Give `Slice` an opening stream and a method that returns the closing stream for each opening. Edits outside a slice are dropped. Here the slice opens when the task becomes urgent and closes when it stops being urgent.
+
+```csharp
+TodoItem item = new() { Title = DraftTitle };
+var becameUrgent = item.WhenChanged(x => x.Priority).Where(static priority => priority == TodoPriority.High);
+
+using var subscription = item.WhenChanged(x => x.Title)
+    .Skip(1)
+    .Slice(becameUrgent, _ => item.WhenChanged(x => x.Priority).Where(static priority => priority != TodoPriority.High))
+    .SelectMany(static slice => slice.ToList())
+    .Subscribe(static titles => Console.WriteLine(string.Join(Separator, titles)));
+
+item.Title = FirstTitle;
+item.Priority = TodoPriority.High;
+item.Title = SecondTitle;
+item.Title = ThirdTitle;
+item.Priority = TodoPriority.Normal;
+item.Title = FourthTitle;
+```
+
+```text
+Renew car, Renew car registration
+```
+
+### Count changes in a window
+
+`Window` takes the same arguments as `Slice`. A time window opens even when nothing happens in it, so a quiet window counts zero.
+
+```csharp
+VirtualClock clock = new();
+TodoItem item = new();
+
+using var subscription = item.WhenChanged(x => x.Notes)
+    .Skip(1)
+    .Window(_windowLength, clock)
+    .SelectMany(static window => window.Count())
+    .Subscribe(static count => Console.WriteLine($"Edits in the window: {count}"));
+
+item.Notes = FirstNote;
+item.Notes = SecondNote;
+item.Notes = ThirdNote;
+clock.AdvanceBy(_windowLength);
+item.Notes = FirstNote;
+clock.AdvanceBy(_windowLength);
+clock.AdvanceBy(_windowLength);
+```
+
+```text
+Edits in the window: 3
+Edits in the window: 1
+Edits in the window: 0
+```
+
+A method that returns a closing stream ends each window in the same way. Here a change of the checkbox ends the window, and the example counts the edits made before it.
+
+```csharp
+TodoItem item = new();
+
+using var subscription = item.WhenChanged(x => x.Notes)
+    .Skip(1)
+    .Window(() => item.WhenChanged(x => x.IsDone).Skip(1))
+    .SelectMany(static window => window.Count())
+    .Subscribe(static count => Console.WriteLine($"Edits before the checkbox changed: {count}"));
+
+item.Notes = FirstNote;
+item.Notes = SecondNote;
+item.IsDone = true;
+item.Notes = ThirdNote;
+item.IsDone = false;
+```
+
+```text
+Edits before the checkbox changed: 2
+Edits before the checkbox changed: 1
+```
+
+### Keep a running value with Scan
+
+`Scan` folds each value into a running value and delivers the running value after every value. The first argument is the starting value, and the second is a lambda that combines the running value with the next one.
+
+```csharp
+TodoItem item = new();
+
+using var subscription = item.WhenChanged(x => x.Notes)
+    .Skip(1)
+    .Scan(0, static (count, _) => count + 1)
+    .Subscribe(static count => Console.WriteLine($"Edits: {count}"));
+
+item.Notes = FirstNote;
+item.Notes = SecondNote;
+item.Notes = ThirdNote;
+```
+
+```text
+Edits: 1
+Edits: 2
+Edits: 3
+```
+
+The next example keeps the highest amount the customer has typed. This stream keeps its current value, so the first delivery is the starting value.
+
+```csharp
+TransferDraft draft = new();
+
+using var subscription = draft.WhenChanged(x => x.Amount)
+    .Scan(0M, Math.Max)
+    .Subscribe(static highest => Console.WriteLine($"Highest: {highest}"));
+
+draft.Amount = FirstAmount;
+draft.Amount = SecondAmount;
+draft.Amount = ThirdAmount;
+```
+
+```text
+Highest: 0
+Highest: 250
+Highest: 250
+Highest: 400
+```
+
+### Group changes by key
+
+`GroupBy` splits a stream into one stream for each key. A group arrives when its first value arrives, and it keeps delivering the values with that key. `ObserveEdits` in the example merges the title edits and the notes edits into one stream of field and value pairs. The example below counts the edits of each field with `Scan`, one group per field.
+
+```csharp
+TodoItem item = new();
+
+using var subscription = ObserveEdits(item)
+    .GroupBy(static edit => edit.Field, static edit => edit.Value)
+    .SelectMany(static group => group.Scan(0, static (count, _) => count + 1).Select(count => $"{group.Key} edit {count}"))
+    .Subscribe(Console.WriteLine);
+
+item.Title = FirstTitle;
+item.Notes = FirstNote;
+item.Title = SecondTitle;
+item.Notes = SecondNote;
+```
+
+```text
+Title edit 1
+Notes edit 1
+Title edit 2
+Notes edit 2
+```
+
+A key comparer decides which values share a group, and an initial capacity sizes the table of groups. Here the comparer ignores case, so "Car" and "car" are one tag. The group keeps the spelling of its first value.
+
+```csharp
+TodoItem item = new();
+
+using var subscription = item.WhenChanged(x => x.Tags)
+    .Skip(1)
+    .SelectMany(static tags => tags)
+    .GroupBy(static tag => tag, ExpectedTagCount, StringComparer.OrdinalIgnoreCase)
+    .SelectMany(static group => group.Scan(0, static (count, _) => count + 1).Select(count => $"{group.Key}: {count}"))
+    .Subscribe(Console.WriteLine);
+
+item.Tags = ["Car", "Errands"];
+item.Tags = ["car", "admin"];
+```
+
+```text
+Car: 1
+Errands: 1
+Car: 2
+admin: 1
+```
+
+`GroupByUntil` also ends each group. It takes a method that returns the closing stream for a group, and the next value with that key opens a new group. Here a group ends when its field has stayed quiet for 300 ms, and the example reports what was typed in it.
+
+```csharp
+VirtualClock clock = new();
+TodoItem item = new();
+
+using var subscription = ObserveEdits(item)
+    .GroupByUntil(static edit => edit.Field, static edit => edit.Value, group => group.Throttle(_quietPeriod, clock))
+    .SelectMany(static group => group.ToList().Select(values => $"{group.Key}: {string.Join(Separator, values)}"))
+    .Subscribe(Console.WriteLine);
+
+item.Title = FirstTitle;
+clock.AdvanceBy(_editGap);
+item.Notes = FirstNote;
+clock.AdvanceBy(_editGap);
+item.Title = SecondTitle;
+clock.AdvanceBy(_quietPeriod);
+item.Notes = SecondNote;
+clock.AdvanceBy(_quietPeriod);
+```
+
+```text
+Notes: Bring the old plates
+Title: Renew, Renew car registration
+Notes: Bring the plates and the receipt
+```
+
+### Deliver on a sequencer
+
+`WitnessOn` delivers each value on a sequencer that you name, in order. The example uses a `VirtualClock` as the UI thread. The three amounts wait in its queue, and `Start` runs the queue, so all three previews print after the typing.
+
+```csharp
+VirtualClock uiThread = new();
+TransferDraft draft = new();
+
+using var subscription = draft.WhenChanged(x => x.Amount)
+    .Skip(1)
+    .WitnessOn(uiThread)
+    .Subscribe(static amount => Console.WriteLine($"Preview {amount}"));
+
+draft.Amount = FirstAmount;
+draft.Amount = SecondAmount;
+draft.Amount = ThirdAmount;
+Console.WriteLine("Typed three amounts");
+uiThread.Start();
+```
+
+```text
+Typed three amounts
+Preview 10
+Preview 20
+Preview 30
+```
+
+`WitnessLatestOn` delivers on the sequencer and keeps only the newest value that is waiting. Use it when the consumer needs the latest state and not every step, such as a preview that redraws. The same three amounts produce one preview.
+
+```csharp
+VirtualClock uiThread = new();
+TransferDraft draft = new();
+
+using var subscription = draft.WhenChanged(x => x.Amount)
+    .Skip(1)
+    .WitnessLatestOn(uiThread)
+    .Subscribe(static amount => Console.WriteLine($"Preview {amount}"));
+
+draft.Amount = FirstAmount;
+draft.Amount = SecondAmount;
+draft.Amount = ThirdAmount;
+Console.WriteLine("Typed three amounts");
+uiThread.Start();
+```
+
+```text
+Typed three amounts
+Preview 30
+```
+
+Bindings use the same rule for view writes: only the latest value waits. [Threading and platforms](threading.md) explains it.
+
+## Observe an expression built at run time
+
+The APIs above read property paths that you write in your code. Sometimes a program builds the path itself, for example from a column name the user picks. Then the path is an `Expression` value made at run time, and the generator has nothing to read. The three APIs in this section take such expressions.
+
+They read the chain by reflection and carry `RequiresUnreferencedCode`, so none is safe to trim. They use the observation providers registered in the service locator, so register the providers first. [Setup](setup.md) covers the builder, and [Mechanisms](mechanisms.md) covers providers. Prefer `WhenChanged` whenever the path is known when you write the code.
+
+```csharp
+IReactiveUIBindingBuilder builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+
+_ = builder.WithCoreServices().BuildApp();
+```
+
+### WhenAnyDynamic
+
+`WhenAnyDynamic` takes one to twelve chains and a selector that receives an observed change for each chain. It works like `WhenAny` for chains built at run time. A final `bool` argument sets `isDistinct`. It is `true` by default, so a chain reports only when its value changes. Pass `false` to report every notification.
+
+The first example observes the amount of a transfer form. The chain is built with `Expression.Property`, so the compiler never sees a lambda, and the selector turns each observed change into text.
+
+```csharp
+var form = CreateTransferForm();
+var root = Expression.Parameter(typeof(TransferForm), "x");
+
+using (form
+    .WhenAnyDynamic(
+        Expression.Property(root, nameof(TransferForm.Amount)),
+        static amount => $"{amount.Value}")
+    .Subscribe(Console.WriteLine))
+{
+    form.Amount = RevisedAmount;
+}
+```
+
+```text
+250
+300
+```
+
+The second example observes two chains, the amount and the reference, and passes `false` for `isDistinct`. The selector receives one observed change for each chain and joins their values.
+
+```csharp
+var form = CreateTransferForm();
+var root = Expression.Parameter(typeof(TransferForm), "x");
+
+using (form
+    .WhenAnyDynamic(
+        Expression.Property(root, nameof(TransferForm.Amount)),
+        Expression.Property(root, nameof(TransferForm.Reference)),
+        static (amount, reference) => $"{amount.Value} {reference.Value}",
+        false)
+    .Subscribe(Console.WriteLine))
+{
+    form.Amount = RevisedAmount;
+}
+```
+
+```text
+250 Rent March
+300 Rent March
+```
+
+### ObservableForProperty
+
+`ObservableForProperty` observes one property and delivers an observed change for each change. Pass a lambda, or pass the property name as a string. Your editor does not list it, so type the call yourself. If no registered provider can observe the property, it throws an `InvalidOperationException`.
+
+Three arguments control the observation. `SubscribeToExpressionChain`, described below, adds a fourth. Each short overload leaves out the arguments it fixes at the default.
+
+| Argument | Meaning | Default |
+| --- | --- | --- |
+| `beforeChange` | Deliver just before the property changes | `false` |
+| `skipInitial` | Skip the current value that arrives on subscription | `true` |
+| `isDistinct` | Drop a value equal to the one before it | `true` |
+| `suppressWarnings` | Observe a property that cannot notify without a warning; only `SubscribeToExpressionChain` takes it | `false` |
+
+The default skips the current value, so only changes arrive. The example below observes the amount by lambda and prints only the value after the change.
+
+```csharp
+TransferForm form = new() { Amount = RentAmount };
+
+using (form.ObservableForProperty(x => x.Amount).Subscribe(static change => Console.WriteLine(change.Value)))
+{
+    form.Amount = RevisedAmount;
+}
+```
+
+```text
+300
+```
+
+Pass `true` for all three arguments to receive the value before each change.
+
+```csharp
+TransferForm form = new() { Amount = RentAmount };
+
+using (form.ObservableForProperty(x => x.Amount, true, true, true).Subscribe(static change => Console.WriteLine(change.Value)))
+{
+    form.Amount = RevisedAmount;
+}
+```
+
+```text
+250
+```
+
+By name, write both type arguments and pass the property name. This call observes the reference.
+
+```csharp
+TransferForm form = new() { Reference = RentReference };
+
+using (form.ObservableForProperty<TransferForm, string>(nameof(TransferForm.Reference)).Subscribe(static change => Console.WriteLine(change.Value)))
+{
+    form.Reference = RevisedReference;
+}
+```
+
+```text
+Rent March, paid early
+```
+
+A second argument of `false` keeps the current value, so the subscriber receives the reference at once and again after the change.
+
+```csharp
+TransferForm form = new() { Reference = RentReference };
+
+using (form.ObservableForProperty<TransferForm, string>(nameof(TransferForm.Reference), false).Subscribe(static change => Console.WriteLine(change.Value)))
+{
+    form.Reference = RevisedReference;
+}
+```
+
+```text
+Rent March
+Rent March, paid early
+```
+
+The long form by name takes all three arguments too. This call asks for the reference before it changes, and it skips the current value, so it prints the value the change replaces.
+
+```csharp
+TransferForm form = new() { Reference = RentReference };
+
+using (form.ObservableForProperty<TransferForm, string>(nameof(TransferForm.Reference), true, true, true).Subscribe(static change => Console.WriteLine(change.Value)))
+{
+    form.Reference = RevisedReference;
+}
+```
+
+```text
+Rent March
+```
+
+### SubscribeToExpressionChain
+
+`SubscribeToExpressionChain` observes a chain that you built as an expression. It takes an `Expression` and the same arguments as `ObservableForProperty`, and its longest overload adds `suppressWarnings`, which turns off the warning the engine writes when it cannot observe a link. It delivers the value at the end of the chain and follows each link as the objects on the chain change.
+
+```csharp
+TransferForm form = new() { Amount = RentAmount };
+Expression<Func<TransferForm, decimal>> amount = x => x.Amount;
+
+using (form.SubscribeToExpressionChain<TransferForm, decimal>(amount.Body, false).Subscribe(static change => Console.WriteLine(change.Value)))
+{
+    form.Amount = RevisedAmount;
+}
+```
+
+```text
+250
+300
+```
+
+Pass `true` for `beforeChange`, `skipInitial` and `isDistinct` to receive the value before each change.
+
+```csharp
+TransferForm form = new() { Amount = RentAmount };
+Expression<Func<TransferForm, decimal>> amount = x => x.Amount;
+
+using (form.SubscribeToExpressionChain<TransferForm, decimal>(amount.Body, true, true, true).Subscribe(static change => Console.WriteLine(change.Value)))
+{
+    form.Amount = RevisedAmount;
+}
+```
+
+```text
+250
+```
+
+The five-argument overload adds `suppressWarnings`. Pass `true` to observe a link that cannot notify without a warning.
+
+```csharp
+TransferForm form = new() { Amount = RentAmount };
+Expression<Func<TransferForm, decimal>> amount = x => x.Amount;
+
+using (form.SubscribeToExpressionChain<TransferForm, decimal>(amount.Body, false, true, true, true).Subscribe(static change => Console.WriteLine(change.Value)))
+{
+    form.Amount = RevisedAmount;
+}
+```
+
+```text
+300
+```
+
+A link that is a plain class has no notification of its own. The fallback provider observes it: it delivers the current value once and then nothing, and the subscription stays open. It writes a debug message the first time it observes each type and property, and `suppressWarnings` set to `true` skips that message. A chain over such a link can deliver a value twice although `isDistinct` is `true`.
+
+The run-time engine follows the same null rules as generated code. It delivers nothing while an object before the last property is null, and it delivers a null last property as a value. If a value cannot be cast to the value type you asked for, the stream ends with an `InvalidCastException`.
+
+## Small value types
+
+Two record structs carry the settings and results of observation. Both are read-only, so two values are equal when every member is equal.
+
+`ExpressionChainParameters<TSender>` bundles what the run-time engine needs to observe one chain: the object, the chain as an expression, its links and the four options. Its text names each member, like `PropertyValues`.
+
+```csharp
+TransferForm form = new() { Amount = RentAmount };
+Expression<Func<TransferForm, decimal>> amount = x => x.Amount;
+Expression[] links = [amount.Body];
+ExpressionChainParameters<TransferForm> parameters = new(form, amount.Body, links, false, true, true, false);
+
+var (source, expression, chain, beforeChange, skipInitial, isDistinct, suppressWarnings) = parameters;
+
+Console.WriteLine(source?.Amount);
+Console.WriteLine(expression);
+Console.WriteLine(chain.Length);
+Console.WriteLine(beforeChange);
+Console.WriteLine(skipInitial);
+Console.WriteLine(isDistinct);
+Console.WriteLine(suppressWarnings);
+```
+
+```text
+250
+x.Amount
+1
+False
+True
+True
+False
+```
+
+Two bundles are equal when every member is equal, and equal bundles have the same hash code.
+
+```csharp
+TransferForm form = new() { Amount = RentAmount };
+Expression<Func<TransferForm, decimal>> amount = x => x.Amount;
+Expression[] links = [amount.Body];
+ExpressionChainParameters<TransferForm> after = new(form, amount.Body, links, false, true, true, false);
+ExpressionChainParameters<TransferForm> sameAfter = new(form, amount.Body, links, false, true, true, false);
+ExpressionChainParameters<TransferForm> before = new(form, amount.Body, links, true, true, true, false);
+
+Console.WriteLine(after == sameAfter);
+Console.WriteLine(after != before);
+Console.WriteLine(after.Equals(sameAfter));
+Console.WriteLine(after.Equals((object)before));
+Console.WriteLine(after.GetHashCode() == sameAfter.GetHashCode());
+```
+
+```text
+True
+True
+True
+False
+True
+```
+
+The text of a bundle names each member. The example splits the text at each comma to print one member per line.
+
+```csharp
+TransferForm form = new() { Amount = RentAmount };
+Expression<Func<TransferForm, decimal>> amount = x => x.Amount;
+Expression[] links = [amount.Body];
+ExpressionChainParameters<TransferForm> parameters = new(form, amount.Body, links, false, true, true, false);
+
+var text = parameters.ToString();
+
+foreach (var member in text.TrimEnd(' ', '}').Split(", "))
+{
+    Console.WriteLine(member);
+}
+```
+
+```text
+ExpressionChainParameters { Source = ReactiveUI.Binding.Documentation.Observing.TransferForm
+Expression = x.Amount
+Links = System.Linq.Expressions.Expression[]
+BeforeChange = False
+SkipInitial = True
+IsDistinct = True
+SuppressWarnings = False
+```
+
+`BindingChange` is the value a binding reports each time it writes. It holds the value written and whether the write went from the view model to the view. [Bindings](bindings.md) shows where a binding reports it. Two changes are equal when both members are equal. The example below compares three changes, and only the change that went the other way differs.
+
+```csharp
+BindingChange fromViewModel = new(RenamedTitle, true);
+BindingChange sameChange = new(RenamedTitle, true);
+BindingChange fromView = new(RenamedTitle, false);
+
+Console.WriteLine(fromViewModel == sameChange);
+Console.WriteLine(fromViewModel != fromView);
+Console.WriteLine(fromViewModel.Equals(sameChange));
+Console.WriteLine(fromViewModel.Equals((object)fromView));
+Console.WriteLine(fromViewModel.GetHashCode() == sameChange.GetHashCode());
+```
+
+```text
+True
+True
+True
+False
+True
+```
+
+The text of a change names each member. The example prints one change so you can see the member names.
+
+```csharp
+BindingChange change = new(RenamedTitle, true);
+
+var text = change.ToString();
+
+Console.WriteLine($"Change: {text}.");
+```
+
+```text
+Change: BindingChange { Value = Renew car registration online, FromViewModel = True }.
+```
+
+## Where to go next
+
+- [Bindings](bindings.md) copies observed values into views.
+- [Mechanisms](mechanisms.md) explains how a type announces a change and how the generator picks a way to listen.
+- [Threading and platforms](threading.md) explains where observed values are delivered.
+- [Unsafe twins and the runtime fallback](unsafe.md) covers calls the generator cannot read.
+- [API reference](api.md) lists every public type and member.
+
+## API reference
+
+The [full API reference](api.md) lists every overload. Each row below covers one member, and a member with many overloads by property count appears once with its largest form.
+
+| Member | What it does | Type and values | Notes |
+| --- | --- | --- | --- |
+| [`WhenChanged`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenChanged.WideArity.cs) | Observes properties and delivers their values on subscription and after each change that alters them. | Extension method on a reference type. One to sixteen properties. Returns `IObservable<T1>` for one property and `IObservable<PropertyValues<...>>` for two or more. A selector as the last argument returns `IObservable<TReturn>`. | The stub throws `InvalidOperationException` when no generated dispatch matches the call site. See [Unsafe twins](unsafe.md). |
+| [`WhenChanging`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenChanging.WideArity.cs) | Observes properties and delivers their values on subscription and just before each change. | Same shapes as `WhenChanged`: one to sixteen properties, with or without a selector. | The object must raise `INotifyPropertyChanging.PropertyChanging`. The analyzer reports RXUIBIND004 when it cannot. |
+| [`WhenAnyValue`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenAnyValue.WideArity.cs) | Observes properties and delivers their values on subscription and after each change that alters them. | Same shapes as `WhenChanged`: one to sixteen properties, with or without a selector. | Delivers the same values as `WhenChanged`. |
+| [`WhenAny`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenAny.WideArity.cs) | Observes properties and delivers the result of a selector that receives one observed change per property. | One to twelve properties. The selector is required. Returns `IObservable<TRet>`. | A change from generated code has a null `Expression`. |
+| [`WhenAnyDynamic`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenAnyDynamic.WideArity.cs) | Observes property chains that a program built as `Expression` values, and delivers the selector's result. | One to twelve `Expression?` chains and a selector. The optional `isDistinct` argument is `true` by default. | Reads by reflection and carries `RequiresUnreferencedCode`. Not safe to trim. |
+| [`WhenAnyObservable`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenAnyObservable.WideArity.cs) | Observes properties that hold `IObservable<T>` and delivers the values of the streams they hold. | One to twelve properties. Streams of one element type merge. A selector as the last argument combines the latest value of each. | A property that holds null delivers nothing. When a property changes, the old stream is dropped and the new one is followed. A selector result starts once every stream has delivered. |
+| [`PropertyValues<T1, ..., T16>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Observables/Values/PropertyValues%7BT1,%20T2,%20T3,%20T4,%20T5,%20T6,%20T7,%20T8,%20T9,%20T10,%20T11,%20T12,%20T13,%20T14,%20T15,%20T16%7D.cs) | Holds the values of several observed properties as one emission. | Read-only record struct with members `Property1` to `Property16`. Two to sixteen type arguments. | Supports deconstruction, value equality, `with` copies and a `ToString` that names each member. |
+| [`IObservedChange<TSender, TValue>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IObservedChange.cs) | Describes one property change. | Read-only members `Sender` (`TSender`), `Expression` (`Expression?`) and `Value` (`TValue`). | `Value` is the default when a source raises a notification without reading the property. |
+| [`ObservedChange<TSender, TValue>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/ObservedChange.cs) | The class behind `IObservedChange`. | Constructor takes `sender`, `expression` (`Expression?`) and `value`. | Pass a null expression when no expression tree is needed. |
+| [`GetPropertyName`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/ObservedChangedMixins.cs) | Returns the dotted path of the property a change describes, such as `A.B[0].C`. | Extension on `IObservedChange<TSender, TValue>`. Returns `string`. | Throws `ArgumentNullException` when the change or its expression is null. |
+| [`GetValue`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/ObservedChangedMixins.cs) | Returns the value a change carries, or reads it from the sender when the carried value is the default. | Extension on `IObservedChange<TSender, TValue>`. Returns `TValue`. | Throws `InvalidOperationException` when an object in the middle of the path is null. Carries `RequiresUnreferencedCode`. |
+| [`GetValueOrDefault`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/ObservedChangedMixins.cs) | Returns what `GetValue` returns, or the default when an object in the middle of the path is null. | Extension on `IObservedChange<TSender, TValue>`. Returns `TValue?`. | Carries `RequiresUnreferencedCode`. |
+| [`Value()`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/ObservedChangedMixins.cs) | Turns a stream of observed changes into a stream of current values. | Extension on `IObservable<IObservedChange<TSender, TValue>>`. Returns `IObservable<TValue>`. | A change whose expression cannot be followed ends the stream with `InvalidOperationException`. Carries `RequiresUnreferencedCode`. |
+| [`ObservableForProperty`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/ReactiveNotifyPropertyChangedMixins.cs) | Observes one property by lambda or by name through the highest-affinity provider registered. | Optional `beforeChange`, `skipInitial` and `isDistinct` arguments. The short forms use `false`, `true` and `true`. | Throws `ArgumentNullException` for a null object, lambda or name, and `InvalidOperationException` when no provider bids. Hidden from IntelliSense. Carries `RequiresUnreferencedCode`. |
+| [`SubscribeToExpressionChain`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/ReactiveNotifyPropertyChangedMixins.cs) | Observes a property chain built as an `Expression`, and follows each link as objects on the chain change. | Optional `beforeChange`, `skipInitial`, `isDistinct` and `suppressWarnings` arguments. The defaults are `false`, `true`, `true` and `false`. | Delivers nothing while an object before the last property is null. A value that cannot be cast to `TValue` ends the stream with `InvalidCastException`. |
+| [`ExpressionChainParameters<TSender>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/ExpressionChainParameters.cs) | Bundles what the run-time engine needs to observe one chain. | Read-only record struct: `Source`, `Expression`, `Links`, `BeforeChange`, `SkipInitial`, `IsDistinct`, `SuppressWarnings`. | Hidden from IntelliSense. Two bundles are equal when every member is equal. |
+| [`ExpressionChainSink<TSender, TValue>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/ExpressionChainSink.cs) | The observable behind a chain: it delivers the value of the last link each time any link changes. | Sealed class implementing `IObservable<IObservedChange<TSender, TValue>>`. | Returned by `SubscribeToExpressionChain` and by the expression forms of `ObservableForProperty`. |
+| [`ObservableForPropertySink<TSender, TValue>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/ObservableForProperty/ObservableForPropertySink.cs) | The observable behind one property: it delivers the value on subscription, unless skipped, and on each notification. | Sealed class implementing `IObservable<IObservedChange<TSender, TValue>>`. | Returned by the by-name forms of `ObservableForProperty`. It reads the value on every notification and ignores the notification's own value. A read that throws reaches the observer as an error. |
+| [`ExpressionMixins`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/ExpressionMixins.cs) | Takes property-access expression trees apart. | Extension members on `Expression`: `GetExpressionChain`, `GetMemberInfo`, `GetParent`, `GetArgumentsArray`. | `GetParent` returns null for a static member. `GetArgumentsArray` returns null when the expression is not an index expression. |
+| [`Reflection`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/Reflection.cs) | Reads and writes members along a property expression chain by reflection. | Static methods: `ExpressionToPropertyNames`, `Rewrite`, value fetchers and setters, and `TryGet` and `TrySet` chain methods. | The `OrThrow` forms throw when a member is not a field or property. |
diff --git a/docs/documentation/binding/setup.md b/docs/documentation/binding/setup.md
new file mode 100644
index 00000000..d14b0cd2
--- /dev/null
+++ b/docs/documentation/binding/setup.md
@@ -0,0 +1,1236 @@
+---
+Order: 9
+---
+# Setup
+
+[Run the complete page example](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/setup/setup.csproj).
+Two more projects cover the [Native AOT program](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/setup/aot/aot.csproj)
+and the [System.Reactive flavour](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/setup/reactive/reactive.csproj).
+
+A binding call such as `item.WhenChanged(x => x.Title)` has to do real work when the program runs. Something must
+watch the property, convert values, write to controls and find views. This page shows how to install the package
+and how to start the library when your program starts.
+It also shows how to read the build messages that say a call cannot get generated code.
+
+One package brings the generator and the calls. A program that has its own converters, observation providers,
+command binders, platform modules or view mappings also builds a *builder* at startup and registers them.
+Later sections cover the System.Reactive package, Native AOT, two build properties and every analyzer message.
+
+## Get started
+
+**1. Add the package.** One reference brings the runtime library, the source generator and the analyzer.
+A *source generator* is a compiler add-on that writes C# code while your project builds. The generator writes
+one method for every binding call in your code, and the analyzer reports the calls it cannot handle.
+
+```bash
+dotnet add package ReactiveUI.Binding
+```
+
+**2. Import the namespace.** A global using in the project file makes the library available in every file.
+You can write `using ReactiveUI.Binding;` at the top of each file instead. Import `ReactiveUI.Binding`, not
+`ReactiveUI`; the [analyzer section](#keep-dispatch-in-reach) shows why.
+
+```xml
+<ItemGroup>
+  <Using Include="ReactiveUI.Binding" />
+</ItemGroup>
+```
+
+**3. Write a call.** The snippet below watches the title of a to-do item and prints it each time it changes. The lambda
+`x => x.Title` is the *property path*: the properties the call follows, from the object to the value. `WhenChanged`
+delivers the current value first and then every new one, and the `using` block disposes the subscription when you are done.
+
+```csharp
+var item = new TodoItem { Title = "Renew car registration" };
+
+using (item.WhenChanged(x => x.Title).Subscribe(Console.WriteLine))
+{
+    item.Title = RenamedTitle;
+}
+```
+
+```text
+Renew car registration
+Renew car registration online
+```
+
+[Observing properties](observing.md) covers `WhenChanged` and its relatives. [Binding](bindings.md) covers the calls that
+write to a control.
+
+**4. Build the builder at startup.** The snippet below registers every kind of service this page covers in one chain.
+Do this once, when the program starts, because a converting binding reads the converters that `BuildApp()` publishes.
+The chain starts with `RxBindingBuilder.CreateReactiveUIBindingBuilder()` and ends with `BuildApp()`. Each `With` method adds one
+piece of configuration and returns the builder, so the calls chain.
+
+```csharp
+IReactiveUIBindingBuilder builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+
+return builder
+    .WithCoreServices()
+    .WithMaui()
+    .WithPlatformModule(new TodoModule())
+    .WithConverter(new TagListToStringConverter())
+    .WithFallbackConverter(new EnumNameFallbackConverter())
+    .WithSetMethodConverter(new TagListSetMethodConverter())
+    .WithCommandBinder(binder)
+    .WithRegistration(resolver => resolver.RegisterLazySingleton<ICreatesObservableForProperty>(() => provider))
+    .ConfigureViewLocator(static mappings => mappings.Map<TodoListViewModel, TodoView>())
+    .BuildApp();
+```
+
+The next sections take these calls one at a time. `BuildApp()` finishes the work. It does three things:
+
+- It builds the configured services.
+- It publishes the converters to `BindingConverters.Current`, the store that every binding reads. That store is empty until `BuildApp` runs.
+- It marks the library as started, which is what `EnsureInitialized` checks.
+
+`BuildApp()` returns an `IReactiveUIBindingInstance`. Its `Current` property is the resolver that reads the configured services.
+Keep the instance if later code reads services from it, as the sections below do.
+
+**5. Check that the library has started.** `RxBindingBuilder.EnsureInitialized()` throws an `InvalidOperationException` when
+`BuildApp` has not run. The snippet below calls it too early and catches the exception, so you can see the guard work.
+No binding call runs this check for you, so use it at the top of startup code that must not run early.
+
+```csharp
+try
+{
+    RxBindingBuilder.EnsureInitialized();
+}
+catch (InvalidOperationException)
+{
+    Console.WriteLine("Call BuildApp first");
+}
+```
+
+```text
+Call BuildApp first
+```
+
+After `BuildApp`, the same call returns and does nothing. The snippet below makes the call after the build and checks
+that the built application holds a resolver, which shows startup finished.
+
+```csharp
+RxBindingBuilder.EnsureInitialized();
+
+Console.WriteLine(app.Current is not null);
+```
+
+```text
+True
+```
+
+## Create the builder
+
+The builder is a `ReactiveUIBindingBuilder`. It configures a Splat dependency resolver, which is the container that
+holds the library's services. `RxBindingBuilder.CreateReactiveUIBindingBuilder()` uses the application-wide resolver.
+The builder owns a `ConverterService` that holds the three converter registries. The snippet below creates a builder and asks
+for an `int` to `string` converter. The lookup finds nothing, which shows that a new builder registers no converters until
+`WithCoreServices` runs.
+
+```csharp
+var builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+
+Console.WriteLine(builder.ConverterService.TypedConverters.TryGetConverter(typeof(int), typeof(string)) is null);
+```
+
+```text
+True
+```
+
+To configure a resolver you own, call the `CreateReactiveUIBindingBuilder` extension on it, or pass the resolver to the
+`ReactiveUIBindingBuilder` constructor. The builder's `CurrentMutable` is that resolver. The snippet below tries both routes
+and checks that the builder configures the resolver you passed. Use this in a test or in a program that keeps its own container,
+so the configuration never touches the shared resolver.
+
+```csharp
+using ModernDependencyResolver resolver = new();
+var fromResolver = resolver.CreateReactiveUIBindingBuilder();
+
+Console.WriteLine(ReferenceEquals(resolver, fromResolver.CurrentMutable));
+
+using ModernDependencyResolver other = new();
+ReactiveUIBindingBuilder direct = new(other, null);
+
+Console.WriteLine(ReferenceEquals(other, direct.CurrentMutable));
+```
+
+```text
+True
+True
+```
+
+The second constructor argument is the resolver that reads the configured services. It may be `null`.
+
+### Register the core services
+
+`WithCoreServices()` registers the default converters, two observation providers and a default view locator.
+The providers watch types that raise `PropertyChanged` and plain types with a `{PropertyName}Changed` event.
+Calling `WithCoreServices` a second time registers nothing more. Call it first in the chain.
+
+`ReactiveUIBindingModule` registers only the two providers, `INPCObservableForProperty` and `POCOObservableForProperty`.
+Use it on its own when you configure a resolver without a builder. The snippet below runs the module against an empty
+resolver and lists the providers that appear. It shows that these two are the whole of the core observation support.
+
+```csharp
+using ModernDependencyResolver resolver = new();
+ReactiveUIBindingModule module = new();
+
+module.Configure(resolver);
+
+var providers = resolver.GetServices<ICreatesObservableForProperty>().Select(static service => service.GetType()).ToList();
+
+Console.WriteLine(providers.Count);
+Console.WriteLine(providers.Contains(typeof(INPCObservableForProperty)));
+Console.WriteLine(providers.Contains(typeof(POCOObservableForProperty)));
+```
+
+```text
+2
+True
+True
+```
+
+### Chain from the app builder interface
+
+A builder that you hold as Splat's `IAppBuilder` has none of the binding methods. The
+`BuilderMixins` extension methods on `IAppBuilder` add them. `BuildApp`, `WithPlatformModule`, `WithRegistration`,
+`WithConverter`, `WithFallbackConverter`, `WithSetMethodConverter` and `ConfigureViewLocator` all exist on `IAppBuilder`. Each one
+throws an `InvalidOperationException` when the builder behind the interface is not a ReactiveUI.Binding builder.
+The snippet below holds the builder as an `IAppBuilder` and builds through the extension. It shows that `BuildApp` finds the
+binding builder behind the interface and still returns a working application.
+
+```csharp
+using ModernDependencyResolver resolver = new();
+IAppBuilder appBuilder = resolver.CreateReactiveUIBindingBuilder();
+
+var app = appBuilder.BuildApp();
+
+Console.WriteLine(app.Current is not null);
+```
+
+```text
+True
+```
+
+A builder that you hold as `ReactiveUIBindingBuilder` has every method as a member. Each call returns the builder itself, and
+`WithRegistration` runs its action against the resolver at once. The snippet below configures the builder one member at a time,
+builds the application, and then checks each result. The class member `WithCoreServices` returns `IAppBuilder`, so the
+snippet casts to the interface to get the binding builder back. The nine `True` lines show that every registration reached the
+resolver and that the builder returned itself each time.
+
+```csharp
+using ModernDependencyResolver resolver = new();
+var builder = resolver.CreateReactiveUIBindingBuilder();
+TodoItemObservableForProperty provider = new();
+ButtonCommandBinder binder = new();
+
+var core = ((IReactiveUIBindingBuilder)builder).WithCoreServices();
+var module = builder.WithPlatformModule(new TodoModule());
+_ = builder.WithFallbackConverter(new EnumNameFallbackConverter());
+_ = builder.WithSetMethodConverter(new TagListSetMethodConverter());
+_ = builder.WithCommandBinder(binder);
+_ = builder.WithRegistration(registry => registry.RegisterLazySingleton<ICreatesObservableForProperty>(() => provider));
+_ = builder.ConfigureViewLocator(static mappings => mappings.Map<TodoListViewModel, TodoView>());
+
+var app = builder.BuildApp();
+
+TodoListViewModel viewModel = new(InMemoryTodoStore.CreateSeeded());
+
+Console.WriteLine(ReferenceEquals(core, builder));
+Console.WriteLine(ReferenceEquals(module, builder));
+Console.WriteLine(builder.ConverterService.TypedConverters.TryGetConverter(typeof(int), typeof(string)) is not null);
+Console.WriteLine(builder.ConverterService.FallbackConverters.TryGetConverter(typeof(TodoPriority), typeof(string)) is EnumNameFallbackConverter);
+Console.WriteLine(builder.ConverterService.SetMethodConverters.TryGetConverter(typeof(List<string>), typeof(string)) is TagListSetMethodConverter);
+Console.WriteLine(ReferenceEquals(resolver.GetService<ICreatesCommandBinding>(), binder));
+Console.WriteLine(resolver.GetServices<ICreatesObservableForProperty>().Any(service => ReferenceEquals(service, provider)));
+Console.WriteLine(resolver.GetService<IViewLocator>()!.ResolveView(viewModel) is TodoView);
+Console.WriteLine(app.Current is not null);
+```
+
+```text
+True
+True
+True
+True
+True
+True
+True
+True
+True
+```
+
+## Register converters
+
+A *converter* turns a value of one type into a value of another. A label shows text, so a binding from a list of
+tags to a label needs a converter from the list to `string`. The builder holds three kinds. The
+[converters](converters.md) page covers the built-in ones. [Custom converters](custom-converters.md) shows how to write your own.
+
+| Method | Registers | Use it for |
+|--------|-----------|------------|
+| `WithConverter` | An `IBindingTypeConverter` | One pair of types, such as a list of tags to `string` |
+| `WithFallbackConverter` | An `IBindingFallbackConverter` | A rule checked at run time that covers many types, such as any enumeration to its name |
+| `WithSetMethodConverter` | An `ISetMethodBindingConverter` | Writing a value into an indexed position, such as one item of a list |
+
+The snippet below registers one converter of each kind through the `IAppBuilder` extensions. It then asks each registry
+for a converter by its types and checks that the answer is the one you registered. This shows the three registries are
+separate, and that a lookup finds your converter by the pair of types.
+
+```csharp
+using ModernDependencyResolver resolver = new();
+var builder = resolver.CreateReactiveUIBindingBuilder();
+IAppBuilder appBuilder = builder;
+
+_ = appBuilder
+    .WithConverter(new TagListToStringConverter())
+    .WithFallbackConverter(new EnumNameFallbackConverter())
+    .WithSetMethodConverter(new TagListSetMethodConverter());
+
+Console.WriteLine(builder.ConverterService.TypedConverters.TryGetConverter(typeof(IReadOnlyList<string>), typeof(string)) is TagListToStringConverter);
+Console.WriteLine(builder.ConverterService.FallbackConverters.TryGetConverter(typeof(TodoPriority), typeof(string)) is EnumNameFallbackConverter);
+Console.WriteLine(builder.ConverterService.SetMethodConverters.TryGetConverter(typeof(List<string>), typeof(string)) is TagListSetMethodConverter);
+```
+
+```text
+True
+True
+True
+```
+
+The fallback and set-method methods return the builder itself, so you can chain from them too. The snippet below registers
+the two converters one call at a time and checks that each call returned the builder, and that each registry holds its
+converter afterwards.
+
+```csharp
+using ModernDependencyResolver resolver = new();
+var builder = resolver.CreateReactiveUIBindingBuilder();
+IAppBuilder appBuilder = builder;
+
+var fallback = appBuilder.WithFallbackConverter(new EnumNameFallbackConverter());
+var setMethod = appBuilder.WithSetMethodConverter(new TagListSetMethodConverter());
+
+Console.WriteLine(ReferenceEquals(builder, fallback));
+Console.WriteLine(ReferenceEquals(builder, setMethod));
+Console.WriteLine(builder.ConverterService.FallbackConverters.TryGetConverter(typeof(TodoPriority), typeof(string)) is EnumNameFallbackConverter);
+Console.WriteLine(builder.ConverterService.SetMethodConverters.TryGetConverter(typeof(List<string>), typeof(string)) is TagListSetMethodConverter);
+```
+
+```text
+True
+True
+True
+True
+```
+
+After `BuildApp`, a binding uses the registered converter. The snippet below binds the tags of the selected item to a label
+with no converter argument. The registered typed converter turns the list into text, so the label reads `car, admin`. This is
+why you register a converter once at startup instead of at every call.
+
+```csharp
+viewModel.SelectedItem = viewModel.Items[0];
+
+using var binding = view.OneWayBind(viewModel, x => x.SelectedItem!.Tags, v => v.TagsLabel.Text);
+
+Console.WriteLine(view.TagsLabel.Text);
+```
+
+```text
+car, admin
+```
+
+You can also read a converter back from the published store and use it yourself. The snippet below finds the fallback converter
+for an enumeration and converts `TodoPriority.High` to its name. It shows that the converter `BuildApp` published is the one you
+registered.
+
+```csharp
+var converter = BindingConverters.Current.FallbackConverters.TryGetConverter(typeof(TodoPriority), typeof(string));
+
+Console.WriteLine(converter is EnumNameFallbackConverter);
+
+_ = converter!.TryConvert(typeof(TodoPriority), TodoPriority.High, typeof(string), null, out var name);
+
+Console.WriteLine(name);
+```
+
+```text
+True
+High
+```
+
+A set-method converter writes one item of a collection by index. `ResolveSetMethodConverter` finds the one for a collection type
+and an item type. The snippet below resolves the converter for `List<string>` and uses it to replace the item at index 1.
+The list changes in place, and no new list is built.
+
+```csharp
+var converter = BindingConverters.Current.ResolveSetMethodConverter(typeof(List<string>), typeof(string));
+
+Console.WriteLine(converter is TagListSetMethodConverter);
+
+List<string> tags = ["car", "admin"];
+_ = converter!.PerformSet(tags, "money", [1]);
+
+Console.WriteLine(string.Join(", ", tags));
+```
+
+```text
+True
+car, money
+```
+
+## Register observation providers
+
+An *observation provider* tells the library how to watch a property. It implements `ICreatesObservableForProperty`.
+Each provider answers with an *affinity*, a score for a type and property. A higher score means a better fit.
+The [mechanisms](mechanisms.md) page explains the scores and how to write a provider.
+
+The generator picks a provider at build time from the types it can see. A provider registered at run time can outrank that choice.
+When a registered provider scores above the generated mechanism, it watches the property. The generated mechanism wins ties.
+
+The snippet below is the one method that gives this provider its weight. It returns 100 for a `TodoItem` and 0 for every other
+type, which is above the score of an ordinary `PropertyChanged` type, so this provider wins for a `TodoItem`.
+
+```csharp
+public int GetAffinityForObject(Type type, string propertyName, bool beforeChanged) =>
+    type == typeof(TodoItem) && !beforeChanged ? TodoItemAffinity : 0;
+```
+
+Register it with `WithRegistration`. The action receives the resolver, so this is also how you register any other service.
+The snippet below counts the providers in the built application. The three are the two core ones and this one, which shows
+the registration reached the resolver.
+
+```csharp
+Console.WriteLine(app.Current!.GetServices<ICreatesObservableForProperty>().Count());
+```
+
+```text
+3
+```
+
+The snippet below observes the title of an item, changes it, and then prints how many observations the provider served. The
+`1` shows the `WhenChanged` call went through your registered provider and not through the generated observation, so a provider
+you register changes how existing calls watch a type.
+
+```csharp
+using (item.WhenChanged(x => x.Title).Subscribe(Console.WriteLine))
+{
+    item.Title = RenamedTitle;
+}
+
+Console.WriteLine(provider.ObservationCount);
+```
+
+```text
+Renew car registration
+Renew car registration online
+1
+```
+
+## Register platform modules
+
+A *platform module* is an `IModule` that registers the services of one UI framework. The builder's `WithPlatformModule`
+runs a module against the resolver. Each platform package also has a shortcut.
+
+| Method | Package namespace | What the module adds |
+|--------|-------------------|----------------------|
+| `WithWpf` | `ReactiveUI.Binding.Wpf.Builder` | Dependency-property observation and the dispatcher view thread invoker |
+| `WithWinForms` | `ReactiveUI.Binding.WinForms.Builder` | Event-based property observation and the control view thread invoker |
+| `WithMaui` | `ReactiveUI.Binding.Maui.Builder` | The MAUI view thread invoker and the Visibility converters |
+
+A *view thread invoker* moves a write onto the thread that owns a control. [Threading](threading.md) explains how the library
+uses it. `WithMaui` registers the invoker into the built application. The snippet below asks the built application for the
+invoker and checks its type, which shows the MAUI invoker is in place for writes to reach a control's owning thread.
+
+```csharp
+Console.WriteLine(app.Current!.GetService<IViewThreadInvoker>() is DispatcherViewThreadInvoker);
+```
+
+```text
+True
+```
+
+Write a module of your own by implementing `IModule.Configure`. It receives the resolver and registers what your screen needs.
+The snippet below registers the to-do database as a lazy singleton, which the resolver creates the first time something asks
+for it. A module keeps the registrations of one screen in one place instead of spread through startup code.
+
+```csharp
+public void Configure(IMutableDependencyResolver resolver) =>
+    resolver.RegisterLazySingleton<ITodoStore>(static () => InMemoryTodoStore.CreateSeeded());
+```
+
+After `BuildApp`, ask the built application for the service. The snippet below does that. It fails with a clear message if
+the module did not run, so a missing registration shows up at startup and not deep inside a binding.
+
+```csharp
+if (app.Current?.GetService<ITodoStore>() is not InMemoryTodoStore store)
+{
+    throw new InvalidOperationException("The module did not register the to-do database.");
+}
+
+return store;
+```
+
+Registering a module and a plain service through the `IAppBuilder` extensions works the same way. The snippet below registers
+the module and checks that `WithPlatformModule` returned the builder itself. It registers a ready-made store as a
+constant, which is a service that already exists and is handed out as is. It then maps a view model to a view and asks the
+locator for the view, which shows that the whole chain works through the interface.
+
+```csharp
+using ModernDependencyResolver resolver = new();
+var builder = resolver.CreateReactiveUIBindingBuilder();
+IAppBuilder appBuilder = builder;
+
+Console.WriteLine(ReferenceEquals(builder, appBuilder.WithPlatformModule(new TodoModule())));
+
+_ = appBuilder
+    .WithRegistration(static registry => registry.RegisterConstant(InMemoryTodoStore.CreateSeeded()))
+    .ConfigureViewLocator(static mappings => mappings.Map<TodoListViewModel, TodoView>());
+
+var locator = resolver.GetService<IViewLocator>();
+TodoListViewModel viewModel = new(resolver.GetService<InMemoryTodoStore>()!);
+
+Console.WriteLine(locator!.ResolveView(viewModel) is TodoView);
+```
+
+```text
+True
+True
+```
+
+## Register command binders
+
+A *command binder* attaches a command to a control. The generator writes the common patterns itself: a `Command`
+property and a button event. Register a binder for a control that has neither. A binder implements `ICreatesCommandBinding`.
+Its `GetAffinityForObject` method scores the control type, and the highest score attaches the command.
+
+The snippet below is the binder's scoring method. It returns 100 for a MAUI `Button` and 0 for any other control, so this
+binder wins whenever a button is bound.
+
+```csharp
+public int GetAffinityForObject<T>(bool hasEventTarget) => typeof(T) == typeof(Button) ? ButtonAffinity : 0;
+```
+
+Register it with `WithCommandBinder`. The snippet below binds the add command to the add button. The count shows the binder
+attached the command once, and the last line shows the button now holds the view model's own command.
+
+```csharp
+using var binding = view.BindCommand(viewModel, x => x.AddCommand, v => v.AddButton);
+
+Console.WriteLine(binder.BindCount);
+Console.WriteLine(ReferenceEquals(viewModel.AddCommand, view.AddButton.Command));
+```
+
+```text
+1
+True
+```
+
+See [mechanisms](mechanisms.md) for how to write a binder.
+
+## Map view models to views
+
+The *view locator* finds the view for a view model. `ConfigureViewLocator` creates a locator that holds the mappings
+you list and registers it as the application's `IViewLocator`. Call it after `WithCoreServices`, which registers a default locator.
+`Map<TViewModel, TView>` adds one pair. The snippet below asks the locator for the view of a view model and checks the type
+of the answer. It shows that the mapping you registered reaches the locator the rest of the library uses.
+
+```csharp
+var view = ViewLocator.GetCurrent().ResolveView(viewModel);
+
+Console.WriteLine(view is TodoView);
+```
+
+```text
+True
+```
+
+[Views](views.md) covers the locator, view contracts and generated view dispatch.
+
+## Choose the System.Reactive package
+
+The package you reference decides which scheduling type a binding takes. The lean `ReactiveUI.Binding` package uses a
+*sequencer*, the object from `ReactiveUI.Primitives` that decides which thread runs a piece of work. System.Reactive
+uses its own `IScheduler` for the same job. If your program already schedules with System.Reactive, reference the second package.
+
+```bash
+dotnet add package ReactiveUI.Binding.Reactive
+```
+
+`ReactiveUI.Binding.Reactive` is the same library compiled against System.Reactive. Everything that takes an `ISequencer` in the
+lean package takes an `IScheduler` here. The two packages share no type names. Every type in `ReactiveUI.Binding`
+lives in `ReactiveUI.Binding.Reactive` in this package, and the same holds for the platform namespaces. Import the shifted namespace.
+
+```xml
+<ItemGroup>
+  <Using Include="ReactiveUI.Binding.Reactive" />
+</ItemGroup>
+```
+
+The snippet below prints the namespace of the builder type. It shows why you import the shifted namespace: the builder is in
+`ReactiveUI.Binding.Reactive.Builder`, not in `ReactiveUI.Binding.Builder`.
+
+```csharp
+Console.WriteLine(typeof(ReactiveUIBindingBuilder).Namespace);
+```
+
+```text
+ReactiveUI.Binding.Reactive.Builder
+```
+
+The generator detects which package you reference and writes code for it. Reference one runtime package, not both. Each carries
+the generator, and two copies write the same files twice. The platform packages have a `.Reactive` twin as well, such as `ReactiveUI.Binding.Maui.Reactive`.
+
+The startup chain is the same. The snippet below builds an application with the shifted `WithMaui` module and asks it for the
+view thread invoker. The `True` shows the shifted MAUI module registered its invoker, just as the lean one does.
+
+```csharp
+IReactiveUIBindingBuilder builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+
+var app = builder
+    .WithCoreServices()
+    .WithMaui()
+    .BuildApp();
+
+Console.WriteLine(app.Current!.GetService<IViewThreadInvoker>() is DispatcherViewThreadInvoker);
+```
+
+```text
+True
+```
+
+The binding calls read the same as in the lean package. The snippet below binds the count of unfinished items to a label
+and prints the label before and after one item is completed. It shows that the same call, written against the shifted
+namespace, keeps the label in step with the view model.
+
+```csharp
+var viewModel = new TodoListViewModel(InMemoryTodoStore.CreateSeeded());
+var view = new TodoView();
+await viewModel.LoadAsync();
+
+using (viewModel.BindOneWay(view, x => x.RemainingCount, v => v.RemainingLabel.Text, static count => count.ToString(CultureInfo.InvariantCulture)))
+{
+    Console.WriteLine(view.RemainingLabel.Text);
+
+    viewModel.SelectedItem = viewModel.Items[0];
+    await viewModel.CompleteAsync();
+
+    Console.WriteLine(view.RemainingLabel.Text);
+}
+```
+
+```text
+3
+2
+```
+
+A binding writes to the control on the thread that owns it. A call that takes a scheduler takes any System.Reactive
+`IScheduler`, so you can choose where the write runs instead. `ImmediateScheduler.Instance` runs the write at once. The snippet
+below passes it as the last argument, so the label already holds the count when the `using` block starts.
+
+```csharp
+var viewModel = new TodoListViewModel(InMemoryTodoStore.CreateSeeded());
+var view = new TodoView();
+await viewModel.LoadAsync();
+
+using (viewModel.BindOneWay(view, x => x.RemainingCount, v => v.RemainingLabel.Text, static count => count.ToString(CultureInfo.InvariantCulture), ImmediateScheduler.Instance))
+{
+    Console.WriteLine(view.RemainingLabel.Text);
+}
+```
+
+```text
+3
+```
+
+`NewThreadScheduler` starts a thread of its own for the write. The snippet below waits for the label to change, then compares
+the writer thread with the caller thread. The `True` shows the write did not happen on the calling thread, which is what you
+choose a scheduler for.
+
+```csharp
+var viewModel = new TodoListViewModel(InMemoryTodoStore.CreateSeeded());
+var view = new TodoView();
+await viewModel.LoadAsync();
+
+var written = new TaskCompletionSource<int>(TaskCreationOptions.RunContinuationsAsynchronously);
+view.RemainingLabel.PropertyChanged += (_, e) =>
+{
+    if (e.PropertyName == nameof(Label.Text))
+    {
+        _ = written.TrySetResult(Environment.CurrentManagedThreadId);
+    }
+};
+
+var callerThread = Environment.CurrentManagedThreadId;
+
+using (viewModel.BindOneWay(view, x => x.RemainingCount, v => v.RemainingLabel.Text, static count => count.ToString(CultureInfo.InvariantCulture), NewThreadScheduler.Default))
+{
+    var writerThread = await written.Task;
+
+    Console.WriteLine(view.RemainingLabel.Text);
+    Console.WriteLine(writerThread != callerThread);
+}
+```
+
+```text
+3
+True
+```
+
+A `null` scheduler means the thread that owns the target, as if you named none. [Threading](threading.md) covers the choices.
+
+## Publish with Native AOT and trimming
+
+*Native AOT* compiles your program to machine code when you publish it. *Trimming* removes code the publisher cannot see a use for.
+Both work poorly with reflection, because reflection finds types and members by name at run time, and the publisher cannot see those uses.
+
+A generated binding uses no reflection. The generator reads your property paths at build time and writes the exact calls that watch,
+convert and write each property. The published program has nothing to look up by name, so a Native AOT program
+needs no extra configuration for it. The sample project turns on the switches a Native AOT app uses.
+
+```xml
+<PublishAot>true</PublishAot>
+<IsAotCompatible>true</IsAotCompatible>
+<InvariantGlobalization>true</InvariantGlobalization>
+<IlcDisableReflection>true</IlcDisableReflection>
+```
+
+`IlcDisableReflection` removes reflection metadata from the published program, so a binding that needed reflection would fail.
+The program runs three calls. The first observes a title with `WhenChanged`, as in the first walkthrough. It shows that the
+simplest call works in a published program.
+
+```csharp
+var item = new TodoItem { Title = "Renew car registration" };
+
+using (item.WhenChanged(x => x.Title).Subscribe(Console.WriteLine))
+{
+    item.Title = RenamedTitle;
+}
+```
+
+```text
+Renew car registration
+Renew car registration online
+```
+
+The second call turns a flag into words. The snippet below binds the finished flag of an item to the status text of a row, and
+the `static` lambda is the conversion. The row shows `Open` at first and `Done` after the flag changes, so a converting binding
+also works without reflection.
+
+```csharp
+var item = new TodoItem { Title = "File quarterly tax return" };
+var row = new TodoRowView();
+
+using (item.BindOneWay(row, x => x.IsDone, v => v.StatusText, static done => done ? DoneText : OpenText))
+{
+    Console.WriteLine(row.StatusText);
+
+    item.IsDone = true;
+
+    Console.WriteLine(row.StatusText);
+}
+```
+
+```text
+Open
+Done
+```
+
+The third call is a two-way binding, `BindTwoWay`, which carries a value in both directions. The snippet below binds the
+title of an item to the title text of a row. Writing to the row then changes the item, so edits made on the screen reach the
+data without reflection too.
+
+```csharp
+var item = new TodoItem { Title = "Book dentist appointment" };
+var row = new TodoRowView();
+
+using (item.BindTwoWay(row, x => x.Title, v => v.TitleText))
+{
+    Console.WriteLine(row.TitleText);
+
+    row.TitleText = "Book dentist appointment for Friday";
+
+    Console.WriteLine(item.Title);
+}
+```
+
+```text
+Book dentist appointment
+Book dentist appointment for Friday
+```
+
+Publish the program and run the executable to see that no code is generated at run time. The snippet below prints whether the
+runtime can generate code. In a published Native AOT program `RuntimeFeature.IsDynamicCodeSupported` is `false`, so every binding
+above ran from code written at build time. A normal `dotnet run` prints `True`.
+
+```csharp
+Console.WriteLine(RuntimeFeature.IsDynamicCodeSupported);
+```
+
+```text
+False
+```
+
+Every generated binding is safe under trimming and Native AOT. The exception is a call you name with the `Unsafe`
+suffix. Those overloads read the path at run time and carry `RequiresUnreferencedCode`, so the trimmer warns at the call.
+Keep them out of a program that you publish this way. [Unsafe bindings](unsafe.md) lists them.
+
+## Set build properties
+
+Two MSBuild properties change what the generator writes. Set them in the project file. The defaults suit most projects.
+
+### Choose how calls reach generated code
+
+A *dispatch* sends a call to the code the generator wrote for it. There are two ways to do it.
+
+- **An interceptor.** The generator writes a method that the compiler puts in place of your call. This needs Roslyn 4.13 or newer. The call site does not change and the file's namespace does not matter.
+- **A concrete overload.** The generator writes an overload of the binding method that wins method lookup over the runtime stub.
+  Roslyn 4.8 and newer can use it. From C# 10 the generator matches your call by the text of its lambdas. Before C# 10 it matches by file and line.
+
+The package picks the generator for the compiler that builds your project. Set `ReactiveUIBindingUseInterceptors`
+to `false` to keep concrete overloads on a compiler that could intercept.
+
+```xml
+<PropertyGroup>
+  <ReactiveUIBindingUseInterceptors>false</ReactiveUIBindingUseInterceptors>
+</PropertyGroup>
+```
+
+The interceptors live in the `ReactiveUI.Binding.Generated.Interceptors` namespace. The compiler accepts an interceptor only from a namespace
+the project lists in `InterceptorsNamespaces`. The package adds `ReactiveUI.Binding.Generated.Interceptors` to
+that list, after any namespaces you listed, so you do nothing.
+
+### Mark generated files
+
+The generator starts each file it writes with an `<auto-generated/>` comment and a `#pragma warning disable` line. Coverage tools,
+formatters and other analyzers skip files that carry them. Set `ReactiveUIBindingEmitGeneratedCodeMarkers` to `false` to drop
+both lines, for example to read diagnostics that point into the generated code.
+
+```xml
+<PropertyGroup>
+  <ReactiveUIBindingEmitGeneratedCodeMarkers>false</ReactiveUIBindingEmitGeneratedCodeMarkers>
+</PropertyGroup>
+```
+
+### Root namespace and language version
+
+Concrete overloads have to be in a namespace that the call site can see. From C# 10 the generator writes them into the
+project's `RootNamespace` and adds a `global using` of it, so files outside the root namespace reach them. Before C# 10 there are no
+global usings, so the overloads sit in `ReactiveUI.Binding`. A project below C# 10 that grants `InternalsVisibleTo` gets them in its root
+namespace instead, and a file outside it cannot reach them. The analyzer reports that case as RXUIBIND009.
+
+## Read the analyzer messages
+
+The analyzer checks every binding call while you type and while you build. A *diagnostic* is one message with an id, a
+severity, some text and a location. Every id starts with `RXUIBIND`. A diagnostic never stops the build. It tells you that
+a call gets no generated code. That call runs the runtime path, or throws when the runtime stub finds nothing. The stub's message names
+the `Unsafe` overload that resolves the path with reflection.
+
+| Id | Severity | Meaning | Fix |
+|----|----------|---------|-----|
+| RXUIBIND001 | Info | The expression is not an inline lambda | [Write the path in the call](#write-the-path-in-the-call) |
+| RXUIBIND002 | Warning | The observed type raises no notification | [Observe types that raise notifications](#observe-types-that-raise-notifications) |
+| RXUIBIND003 | Warning | The path names a private or protected member | [Write the path in the call](#write-the-path-in-the-call) |
+| RXUIBIND004 | Warning | `WhenChanging` targets a type with no before-change notification | [Observe types that raise notifications](#observe-types-that-raise-notifications) |
+| RXUIBIND005 | Info | The source type implements `INotifyDataErrorInfo` | [Bind the shapes the generator reads](#bind-the-shapes-the-generator-reads) |
+| RXUIBIND006 | Warning | The path has an indexer, a field or a method call | [Write the path in the call](#write-the-path-in-the-call) |
+| RXUIBIND007 | Warning | `BindCommand` finds no event on the control | [Bind the shapes the generator reads](#bind-the-shapes-the-generator-reads) |
+| RXUIBIND008 | Warning | The property is not an interaction | [Bind the shapes the generator reads](#bind-the-shapes-the-generator-reads) |
+| RXUIBIND009 | Warning | The call site cannot reach the generated dispatch | [Keep dispatch in reach](#keep-dispatch-in-reach) |
+| RXUIBIND010 | Warning | The path passes through a type that raises no notification | [Observe types that raise notifications](#observe-types-that-raise-notifications) |
+| RXUIBIND011 | Warning | The call resolved to ReactiveUI's own mixin | [Keep dispatch in reach](#keep-dispatch-in-reach) |
+
+`RXUIBIND100` is an MSBuild error, not an analyzer message. It appears when the compiler is older than Roslyn 4.8 and reads:
+"ReactiveUI.Binding's source generator requires Roslyn 4.8 or later (Visual Studio 2022 17.8+, or .NET SDK 8.0.100+)". Upgrade the build tools.
+
+RXUIBIND002 and RXUIBIND004 are reported only when the generator uses interceptors. On a compiler older than Roslyn 4.13, or with
+`ReactiveUIBindingUseInterceptors` set to `false`, those two do not appear.
+
+### Write the path in the call
+
+The generator reads a lambda written in the call: `x => x.Title`. RXUIBIND001 reports a path held in a variable, because the
+generator cannot see into a variable.
+
+```text
+Expression<Func<TodoItem, string>> titlePath = x => x.Title;
+item.WhenChanged(titlePath);
+
+info RXUIBIND001: Expression must be inline lambda
+```
+
+Write the lambda in the call. The snippet below does, so the generator can read `x.Title` at build time. It prints the current
+title and then the new one, exactly as in the first walkthrough.
+
+```csharp
+var item = new TodoItem { Title = "Renew car registration" };
+
+using (item.WhenChanged(x => x.Title).Subscribe(Console.WriteLine))
+{
+    item.Title = RenamedTitle;
+}
+```
+
+```text
+Renew car registration
+Renew car registration online
+```
+
+The generated method is a separate method in another class, so it cannot read a private or protected member.
+RXUIBIND003 reports a path that names one.
+
+```text
+this.WhenChanged(x => x.Draft)
+
+warning RXUIBIND003: Expression contains private or protected member
+```
+
+Make the property public and observe it. The snippet below observes `NewTitle`, a public property of the view model. The
+title is set before the subscription, so the first line is the value that was already there and the second is the change.
+
+```csharp
+var viewModel = new TodoListViewModel(InMemoryTodoStore.CreateSeeded());
+
+viewModel.NewTitle = DentistTitle;
+
+using (viewModel.WhenChanged(x => x.NewTitle).Subscribe(Console.WriteLine))
+{
+    viewModel.NewTitle = "Buy birthday present for Sam";
+}
+```
+
+```text
+Book dentist appointment
+Buy birthday present for Sam
+```
+
+A path follows properties. An indexer, a field or a method call has no notification to follow, so RXUIBIND006 reports it.
+It reports all three shapes.
+
+```text
+viewModel.WhenChanged(x => x.Items[0].Title)
+viewModel.WhenChanged(x => x.SelectedItem!.Title.ToUpperInvariant())
+this.WhenChanged(x => x.Query)
+
+warning RXUIBIND006: Expression contains unsupported path segment
+```
+
+The last line names `Query`, a public field. Replace each with a property. The snippet below follows two properties,
+`SelectedItem` and then its `Title`. When `SelectedItem` changes, the observation moves to the new item's `Title`, so the
+output shows both titles.
+
+```csharp
+var viewModel = new TodoListViewModel(InMemoryTodoStore.CreateSeeded());
+await viewModel.LoadAsync();
+viewModel.SelectedItem = viewModel.Items[0];
+
+using (viewModel.WhenChanged(x => x.SelectedItem!.Title).Subscribe(Console.WriteLine))
+{
+    viewModel.SelectedItem = viewModel.Items[1];
+}
+```
+
+```text
+Renew car registration
+Book dentist appointment
+```
+
+### Observe types that raise notifications
+
+A type raises a *notification* when a property changes, for example a `PropertyChanged` event. A type that raises
+nothing never reports a change. RXUIBIND002 reports a call on such a type. Here `stored` is a `StorageObject`, a plain class.
+
+```text
+stored.WhenChanged(x => x.Size)
+
+warning RXUIBIND002: Type has no observable properties
+```
+
+Observe a type that raises `PropertyChanged`. The snippet below observes `IsDone` on a `TodoItem`, which does. The output shows
+the value at subscription and then the change, so you see every value the flag takes.
+
+```csharp
+var item = new TodoItem { Title = "File quarterly tax return" };
+
+using (item.WhenChanged(x => x.IsDone).Subscribe(Console.WriteLine))
+{
+    item.IsDone = true;
+}
+```
+
+```text
+False
+True
+```
+
+A silent type in the middle of a path is a different problem. The observation reads the silent object once and never follows the path
+past it. RXUIBIND010 reports it. Here `Connection` is a `StorageConnection` that raises nothing.
+
+```text
+viewModel.WhenChanged(x => x.Connection.State)
+
+warning RXUIBIND010: Type 'StorageConnection' raises no notification, so 'x.Connection' is read once and the observation stops following the path there
+```
+
+Observe a property of the view model that mirrors the state instead. The snippet below observes `ConnectionStatus` on a browser
+view model. The view model raises the notification, so the output follows the link going down and coming back up.
+
+```csharp
+var storage = InMemoryObjectStorage.CreateSeeded();
+var browser = new StorageBrowserViewModel(storage);
+
+using (browser.WhenChanged(x => x.ConnectionStatus).Subscribe(static state => Console.WriteLine(state)))
+{
+    storage.Disconnect();
+    await browser.ConnectAsync();
+}
+```
+
+```text
+Connected
+Disconnected
+Connecting
+Connected
+```
+
+`WhenChanging` needs a type that raises `PropertyChanging`. On a type that raises only `PropertyChanged`, RXUIBIND004
+reports the call, and the observation reads the value once and stays silent.
+
+```text
+item.WhenChanging(x => x.Title)
+
+warning RXUIBIND004: Type does not support before-change notifications
+```
+
+Observe a type that raises `PropertyChanging`. The snippet below uses `EditableTodo`, which raises it before each change.
+`WhenChanging` prints the current title when you subscribe and again just before the change replaces it, so the same text
+appears twice.
+
+```csharp
+var todo = new EditableTodo { Title = DentistTitle };
+
+using (todo.WhenChanging(x => x.Title).Subscribe(Console.WriteLine))
+{
+    todo.Title = "Book dentist appointment for Friday";
+}
+```
+
+```text
+Book dentist appointment
+Book dentist appointment
+```
+
+### Bind the shapes the generator reads
+
+The generator writes a `BindCommand` binding for a control that has an event to listen to. RXUIBIND007 reports a control without one.
+Here the control is an `Entry`.
+
+```text
+view.BindCommand(viewModel, x => x.AddCommand, v => v.NewTitleTextBox)
+
+warning RXUIBIND007: Control type 'Entry' has no default bindable event (Click, TouchUpInside, Pressed) and no 'toEvent' was specified
+```
+
+Bind to a button, or name the event in the `toEvent` argument. The snippet below binds the add command to the add button and
+prints whether the command can run, before and after the view model gets a title. The button follows the view model's
+`CanExecute`, so the answer changes from `False` to `True`.
+
+```csharp
+var viewModel = new TodoListViewModel(InMemoryTodoStore.CreateSeeded());
+var view = new TodoView { ViewModel = viewModel };
+
+using (view.BindCommand(viewModel, x => x.AddCommand, v => v.AddButton))
+{
+    Console.WriteLine(view.AddButton.Command!.CanExecute(null));
+
+    viewModel.NewTitle = DentistTitle;
+
+    Console.WriteLine(view.AddButton.Command.CanExecute(null));
+}
+```
+
+```text
+False
+True
+```
+
+A view model that implements `INotifyDataErrorInfo` raises RXUIBIND005 when you bind a value from it. The generator writes the value
+binding. It does not carry the validation state.
+
+```text
+viewModel.BindTwoWay(view, x => x.AmountText, v => v.NewTitleTextBox.Text)
+
+info RXUIBIND005: Validation binding not generated
+```
+
+Expose the errors as a property of the view model and bind that property. The snippet below binds `ValidationSummary` to a
+label, then sets an amount and prints the label. The label shows the summary text, so validation messages reach the screen
+without the generator reading `INotifyDataErrorInfo`.
+
+```csharp
+var viewModel = new TransferViewModel(new InMemoryBankingBackend());
+var view = new TransferView { ViewModel = viewModel };
+
+using (viewModel.BindOneWay(view, x => x.ValidationSummary, v => v.ValidationLabel.Text))
+{
+    viewModel.Draft.Amount = SmallAmount;
+
+    Console.WriteLine(view.ValidationLabel.Text);
+}
+```
+
+```text
+Choose the account to pay from. Choose who to pay.
+```
+
+`BindInteraction` needs a property that is an interaction. RXUIBIND008 reports a property of another type. The compiler
+rejects most such calls first, so this message is rare.
+
+```text
+view.BindInteraction(viewModel, x => x.ErrorMessage, context => Task.CompletedTask)
+
+warning RXUIBIND008: Property is not an IInteraction
+```
+
+Bind a handler to a property that is an interaction. The snippet below answers the interaction with `SetOutput(true)`, then
+asks the question through `Handle` and prints the answer. The `True` shows a property of the right type gets a generated
+binding that works.
+
+```csharp
+var viewModel = new IssueBoardViewModel(InMemoryGitHubServer.CreateSeeded());
+var view = new IssueBoardView { ViewModel = viewModel };
+
+using (view.BindInteraction(viewModel, x => x.ConfirmClose, static context =>
+{
+    context.SetOutput(true);
+    return Task.CompletedTask;
+}))
+{
+    var confirmed = await viewModel.ConfirmClose.Handle(new Issue { Title = "Crash on startup" });
+
+    Console.WriteLine(confirmed);
+}
+```
+
+```text
+True
+```
+
+### Keep dispatch in reach
+
+A call has to reach the code the generator wrote. Two mistakes send it somewhere else.
+
+**Import the right namespace.** A file that imports `ReactiveUI` but not `ReactiveUI.Binding` binds the call to ReactiveUI's
+own `WhenAnyValue`. That method knows nothing of the generator. The call runs the runtime expression engine, and the generator writes no code for it.
+RXUIBIND011 reports this.
+
+```text
+viewModel.WhenAnyValue(x => x.RemainingCount)
+
+warning RXUIBIND011: Binding call resolved to ReactiveUI's own mixin
+```
+
+Import `ReactiveUI.Binding`, as in step 2 of [Get started](#get-started). The snippet below is a file that does, so
+`WhenAnyValue` reaches this package. It prints the count of unfinished items, first `3` and then `2` after one item is completed.
+
+```csharp
+var viewModel = new TodoListViewModel(InMemoryTodoStore.CreateSeeded());
+await viewModel.LoadAsync();
+
+using (viewModel.WhenAnyValue(x => x.RemainingCount).Subscribe(Console.WriteLine))
+{
+    viewModel.SelectedItem = viewModel.Items[0];
+    await viewModel.CompleteAsync();
+}
+```
+
+```text
+3
+2
+```
+
+**Put the file under the root namespace.** RXUIBIND009 needs three things at once. The build uses concrete overloads.
+The project sets `LangVersion` below 10, such as 7.3. The assembly grants `InternalsVisibleTo` to another assembly, such as its test project.
+A file outside the project's root namespace then cannot see the overloads. The call binds to the stub and throws when it runs.
+
+```text
+[assembly: InternalsVisibleTo("TodoApp.Tests")]
+viewModel.WhenChanged(x => x.RemainingCount)
+
+warning RXUIBIND009: Generated binding dispatch is out of reach here
+```
+
+There are three fixes: move the file under the root namespace, raise the language version to 10 or later, or use a compiler
+that intercepts. The snippet below sits under the root namespace of the sample project, `ReactiveUI.Binding.Documentation`,
+so it reaches the dispatch. It prints the count of unfinished items before and after one item is completed.
+
+```csharp
+var viewModel = new TodoListViewModel(InMemoryTodoStore.CreateSeeded());
+await viewModel.LoadAsync();
+
+using (viewModel.WhenChanged(x => x.RemainingCount).Subscribe(Console.WriteLine))
+{
+    viewModel.SelectedItem = viewModel.Items[0];
+    await viewModel.CompleteAsync();
+}
+```
+
+```text
+3
+2
+```
+
+## Where to go next
+
+- [Observing properties](observing.md) covers `WhenChanged`, `WhenChanging`, `WhenAnyValue` and the other observation calls.
+- [Bindings](bindings.md) covers one-way, two-way, command and interaction bindings.
+- [Converters](converters.md) and [custom converters](custom-converters.md) cover what the `With...Converter` methods register.
+- [Mechanisms](mechanisms.md) covers providers, affinity and command binders.
+- [Views](views.md) covers the view locator, and [threading](threading.md) covers invokers and schedulers.
+- [Unsafe bindings](unsafe.md) covers the reflection overloads. The [API reference](api.md) lists every type on this page.
+
+## API reference
+
+| Member | What it does | Type and values | Notes |
+| --- | --- | --- | --- |
+| [`IReactiveUIBindingBuilder`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/IReactiveUIBindingBuilder.cs) | Describes a builder that configures the library's services, converters and platform modules. | Interface that extends Splat's `IAppBuilder`. | Its methods return `IReactiveUIBindingBuilder`, so calls chain. |
+| [`IReactiveUIBindingInstance`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/IReactiveUIBindingInstance.cs) | Represents a configured application. | Interface that extends Splat's `IAppInstance`. | The inherited `Current` property is the resolver that reads the configured services. |
+| [`ReactiveUIBindingBuilder`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingBuilder.cs) | Configures the library on a Splat resolver. The constructor prepares Splat on that resolver and registers the `ConverterService` with it. | Sealed class. Constructor takes `IMutableDependencyResolver resolver` and `IReadonlyDependencyResolver? current`. | `current` may be `null`. `CurrentMutable` is the resolver you passed in. |
+| [`ReactiveUIBindingBuilder.ConverterService`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingBuilder.cs) | Holds the typed, fallback and set-method converter registries that this builder fills. | Read-only `ConverterService`. | Empty until `WithCoreServices` or a `With...Converter` call adds converters. `BuildApp` publishes it to `BindingConverters.Current`. |
+| [`WithCoreServices`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingBuilder.cs) | Registers the default converters, the `PropertyChanged` and plain-object observation providers, and a default view locator. | No parameters. Returns `IAppBuilder` on the class and `IReactiveUIBindingBuilder` on the interface. | A second call registers nothing more. |
+| [`WithPlatformModule`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingBuilder.cs) | Runs a platform module against the resolver. | `T module`, where `T : IModule`. Returns the builder. | Throws `ArgumentNullException` when `module` is `null`. |
+| [`WithRegistration`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingBuilder.cs) | Runs your action against the mutable resolver at the moment of the call. | `Action<IMutableDependencyResolver> configureAction`. Returns the builder. | Throws `ArgumentNullException` when the action is `null`. |
+| [`WithConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingBuilder.cs) | Adds a typed converter for one pair of types. | `IBindingTypeConverter converter`. Returns the builder. | Throws `ArgumentNullException` when `converter` is `null`. |
+| [`WithFallbackConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingBuilder.cs) | Adds a converter that checks types at run time. | `IBindingFallbackConverter converter`. Returns the builder. | Throws `ArgumentNullException` when `converter` is `null`. |
+| [`WithSetMethodConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingBuilder.cs) | Adds a converter that writes a value into an indexed position. | `ISetMethodBindingConverter converter`. Returns the builder. | Throws `ArgumentNullException` when `converter` is `null`. |
+| [`WithCommandBinder`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingBuilder.cs) | Registers a binder that attaches a command to a control. | `ICreatesCommandBinding binder`. Returns the builder. | Registered as a lazy singleton. Throws `ArgumentNullException` when `binder` is `null`. |
+| [`ConfigureViewLocator`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingBuilder.cs) | Creates a `DefaultViewLocator` that holds the mappings you list and registers it as the `IViewLocator`. | `Action<ViewMappingBuilder> configure`. Returns the builder. | Call it after `WithCoreServices`. Throws `ArgumentNullException` when `configure` is `null`. |
+| [`BuildApp`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingBuilder.cs) | Builds the application, publishes the converter service to `BindingConverters.Current` and marks the library as started. | No parameters. Returns `IReactiveUIBindingInstance`. | `RxBindingBuilder.EnsureInitialized` passes after this call. Throws `InvalidOperationException` when the build produces no usable instance. |
+| [`RxBindingBuilder.CreateReactiveUIBindingBuilder`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/RxBindingBuilder.cs) | Creates a builder over the application-wide Splat resolver. | No parameters. Returns `ReactiveUIBindingBuilder`. | Reads services from `AppLocator.Current`. |
+| [`RxBindingBuilder.EnsureInitialized`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/RxBindingBuilder.cs) | Checks that a builder's `BuildApp` has completed. | No parameters. Returns nothing. | Throws `InvalidOperationException` when `BuildApp` has not run. No binding call runs this check. |
+| [`RxBindingBuilderMixins.CreateReactiveUIBindingBuilder`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/RxBindingBuilderMixins.cs) | Creates a builder over a resolver you own. Called on the resolver. | Receiver `IMutableDependencyResolver`. Returns `ReactiveUIBindingBuilder`. | Reads services from the resolver when it is also an `IReadonlyDependencyResolver`, and from `AppLocator.Current` otherwise. Throws `ArgumentNullException` when the resolver is `null`. |
+| [`ReactiveUIBindingModule`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingModule.cs) | Registers the two core observation providers, `INPCObservableForProperty` and `POCOObservableForProperty`. | Sealed class that implements `IModule`. `Configure(IMutableDependencyResolver resolver)` does the work. | Registers both as lazy singletons. Throws `ArgumentNullException` when `resolver` is `null`. |
+| [`BuilderMixins.BuildApp`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/BuilderMixins.cs) | Builds the application from an `IAppBuilder`. | Receiver `IAppBuilder`. Returns `IReactiveUIBindingInstance`. | Throws `ArgumentNullException` for a `null` receiver and `InvalidOperationException` when the receiver is not a binding builder. |
+| [`BuilderMixins.WithPlatformModule`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/BuilderMixins.cs) | Registers a platform module from an `IAppBuilder`. | Receiver `IAppBuilder`; `T module`, where `T : IModule`. Returns `IReactiveUIBindingBuilder`. | Same exceptions as `BuilderMixins.BuildApp`. |
+| [`BuilderMixins.WithRegistration`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/BuilderMixins.cs) | Runs a registration action from an `IAppBuilder`. | Receiver `IAppBuilder`; `Action<IMutableDependencyResolver> configureAction`. Returns `IReactiveUIBindingBuilder`. | Same exceptions as `BuilderMixins.BuildApp`. |
+| [`BuilderMixins.WithConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/BuilderMixins.cs) | Registers a typed converter from an `IAppBuilder`. | Receiver `IAppBuilder`; `IBindingTypeConverter converter`. Returns `IReactiveUIBindingBuilder`. | Same exceptions as `BuilderMixins.BuildApp`. |
+| [`BuilderMixins.WithFallbackConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/BuilderMixins.cs) | Registers a fallback converter from an `IAppBuilder`. | Receiver `IAppBuilder`; `IBindingFallbackConverter converter`. Returns `IReactiveUIBindingBuilder`. | Same exceptions as `BuilderMixins.BuildApp`. |
+| [`BuilderMixins.WithSetMethodConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/BuilderMixins.cs) | Registers a set-method converter from an `IAppBuilder`. | Receiver `IAppBuilder`; `ISetMethodBindingConverter converter`. Returns `IReactiveUIBindingBuilder`. | Same exceptions as `BuilderMixins.BuildApp`. |
+| [`BuilderMixins.ConfigureViewLocator`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/BuilderMixins.cs) | Configures the view locator from an `IAppBuilder`. | Receiver `IAppBuilder`; `Action<ViewMappingBuilder> configure`. Returns `IReactiveUIBindingBuilder`. | Same exceptions as `BuilderMixins.BuildApp`. |
+| [`WithMaui`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Maui.Shared/Builder/MauiBindingBuilderExtensions.cs) | Registers the MAUI module. | Receiver `IAppBuilder` or `IReactiveUIBindingBuilder`. Returns `IReactiveUIBindingBuilder`. | Lives in `ReactiveUI.Binding.Maui.Builder`. The `IAppBuilder` form casts the receiver to `IReactiveUIBindingBuilder`. The interface form throws `ArgumentNullException` for a `null` receiver. |
+| [`WithWpf`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Wpf.Shared/Builder/WpfBindingBuilderExtensions.cs) | Registers the WPF module. | Receiver `IAppBuilder` or `IReactiveUIBindingBuilder`. Returns `IReactiveUIBindingBuilder`. | Lives in `ReactiveUI.Binding.Wpf.Builder`. Same receiver rules as `WithMaui`. |
+| [`WithWinForms`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.WinForms.Shared/Builder/WinFormsBindingBuilderExtensions.cs) | Registers the WinForms module. | Receiver `IAppBuilder` or `IReactiveUIBindingBuilder`. Returns `IReactiveUIBindingBuilder`. | Lives in `ReactiveUI.Binding.WinForms.Builder`. Same receiver rules as `WithMaui`. |
+| [`MauiBindingModule`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Maui.Shared/MauiBindingModule.cs) | Registers the MAUI view thread invoker and the Visibility converters. | Sealed class that implements `IModule`. | The Visibility converters are registered with the resolver only. Throws `ArgumentNullException` when the resolver is `null`. |
+| [`WpfBindingModule`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Wpf.Shared/WpfBindingModule.cs) | Registers dependency-property observation and the dispatcher view thread invoker. | Sealed class that implements `IModule`. | Throws `ArgumentNullException` when the resolver is `null`. |
+| [`WinFormsBindingModule`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.WinForms.Shared/WinFormsBindingModule.cs) | Registers event-based property observation and the control view thread invoker. | Sealed class that implements `IModule`. | Throws `ArgumentNullException` when the resolver is `null`. |
+| [`ReactiveUIBindingUseInterceptors`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/build/ReactiveUI.Binding.SourceGenerators.targets) | Chooses whether the generator replaces each call with an interceptor. | MSBuild property. `true` when unset; set `false` to use concrete overloads. | Interceptors need Roslyn 4.13 or newer. |
+| [`ReactiveUIBindingEmitGeneratedCodeMarkers`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/build/ReactiveUI.Binding.SourceGenerators.props) | Chooses whether generated files start with the `<auto-generated/>` comment and a `#pragma warning disable` line. | MSBuild property. `true` when unset; set `false` to drop both lines. | Visible to the generator through the compiler's property list. |
+| [`InterceptorsNamespaces`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/build/ReactiveUI.Binding.SourceGenerators.targets) | Lists the namespaces the compiler accepts interceptors from. | MSBuild property with `;`-separated names. | The package adds `ReactiveUI.Binding.Generated.Interceptors` after your entries when interceptors are in use. |
+| [`RXUIBIND001`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/DiagnosticWarnings.cs) | Reports a path that is not an inline lambda. | Info. | The call gets no generated code. The `Unsafe` overload reads the path at run time. |
+| [`RXUIBIND002`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/DiagnosticWarnings.cs) | Reports an observed type that raises no notification. | Warning. | Does not appear when concrete overloads dispatch the call. |
+| [`RXUIBIND003`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/DiagnosticWarnings.cs) | Reports a path that names a private or protected member. | Warning. | The call gets no generated code. Make the member public. |
+| [`RXUIBIND004`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/DiagnosticWarnings.cs) | Reports `WhenChanging` on a type with no before-change notification. | Warning. | The observation reads the value once and then stays silent. Does not appear when concrete overloads dispatch the call. |
+| [`RXUIBIND005`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/DiagnosticWarnings.cs) | Reports a source type that implements `INotifyDataErrorInfo`. | Info. | The generated binding carries the value and not the validation state. |
+| [`RXUIBIND006`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/DiagnosticWarnings.cs) | Reports a path with an indexer, a field or a method call. | Warning. | The call gets no generated code. Use properties in the path. |
+| [`RXUIBIND007`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/DiagnosticWarnings.cs) | Reports a `BindCommand` control with no default bindable event. | Warning. | Default events are `Click`, `TouchUpInside` and `Pressed`. Name another event in `toEvent`. |
+| [`RXUIBIND008`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/DiagnosticWarnings.cs) | Reports a `BindInteraction` property that is not an `IInteraction<TInput, TOutput>`. | Warning. | Bind a property of the interaction type. |
+| [`RXUIBIND009`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/DiagnosticWarnings.cs) | Reports a call site the generated dispatch cannot reach. | Warning. | Needs concrete overloads, C# 9 or lower, and `InternalsVisibleTo`. The file must sit under the root namespace. |
+| [`RXUIBIND010`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/DiagnosticWarnings.cs) | Reports a path that passes through a type that raises no notification. | Warning. | The observation reads that link once and stops following the path there. |
+| [`RXUIBIND011`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/DiagnosticWarnings.cs) | Reports a binding call that resolved to ReactiveUI's own mixin. | Warning. | The call generates nothing and uses the runtime expression engine. Import `ReactiveUI.Binding`. |
+| [`RXUIBIND100`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.SourceGenerators/build/ReactiveUI.Binding.SourceGenerators.targets) | Stops the build when the compiler is older than Roslyn 4.8. | Error from MSBuild, not from the analyzer. | The message asks for Visual Studio 2022 17.8 or .NET SDK 8.0.100 or later. |
diff --git a/docs/documentation/binding/threading.md b/docs/documentation/binding/threading.md
new file mode 100644
index 00000000..03d318d5
--- /dev/null
+++ b/docs/documentation/binding/threading.md
@@ -0,0 +1,1551 @@
+---
+Order: 8
+---
+# Threading
+
+[Run the complete page example](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/threading/threading.csproj).
+
+A UI framework lets only one thread touch a control. That thread is the control's **owning thread**. A view model often changes on another thread: a background sync delivers a new title, or an upload reports its progress from a pool thread. If a binding wrote that value to the control from the wrong thread, the framework would throw.
+
+Every binding API that writes to a view keeps the write on the owning thread. This page shows how the engine finds that thread, how you choose where waiting writes run, and what each platform module adds. The observing APIs, such as `WhenChanged`, do not move anything. They deliver on the thread that raised the change, and you decide where to observe. See [observing](observing.md).
+
+The WPF and WinForms examples need Windows and run from the `net10.0-windows10.0.19041.0` build. The Avalonia, MAUI and sequencer examples run on any operating system from the `net10.0` build. [Run the examples](#run-the-examples) shows the commands.
+
+Start with the walkthrough, which uses Avalonia. Later sections cover the invoker contract, the delivery rules, the schedulers you can set, the sequencer overloads and the WPF, WinForms and MAUI modules.
+
+## Write to a control from any thread
+
+**1. See what the framework refuses.** Avalonia throws `InvalidOperationException` when a thread other than the UI thread sets a control property. The control stays as it was. A binding has to avoid this call. The example below sets `Text` from a worker thread and records whether Avalonia refused. It shows the failure that every later step avoids.
+
+```csharp
+TextBlock titleLabel = new();
+var refused = false;
+
+var worker = new Thread(() =>
+{
+    try
+    {
+        titleLabel.Text = RenamedTitle;
+    }
+    catch (InvalidOperationException)
+    {
+        refused = true;
+    }
+});
+worker.Start();
+worker.Join();
+
+Console.WriteLine(refused);
+Console.WriteLine(titleLabel.Text ?? NoText);
+```
+
+```text
+True
+(no text)
+```
+
+**2. Write an invoker.** An **invoker** is a small object that tells the engine which thread owns a control and how to reach it. It implements `IViewThreadInvoker`, which has three members. `Claims` says whether the object belongs to this invoker's platform. `CheckAccess` says whether the calling thread may write to the object directly. `Post` queues a callback on the owning thread. Avalonia has one UI thread for every control, so the invoker asks Avalonia's `Dispatcher`, the queue that runs work on that thread. The class below is the whole invoker. Each member is one line, because every Avalonia object belongs to that one thread.
+
+```csharp
+public sealed class AvaloniaViewThreadInvoker : IViewThreadInvoker
+{
+    public bool Claims(object target) => target is AvaloniaObject;
+
+    public bool CheckAccess(object target) => Dispatcher.UIThread.CheckAccess();
+
+    public void Post(object target, Action<object?> callback, object? state) =>
+        Dispatcher.UIThread.Post(callback.Invoke, state, DispatcherPriority.Default);
+}
+```
+
+`Post` hands `state` to the callback unchanged. The engine passes its own object as `state`, so the callback needs no captured variables.
+
+**3. Register the invoker.** Register one instance as an `IViewThreadInvoker` service, then call `ViewThreadInvokers.Refresh`. The engine reads the registered invokers once and keeps them. `Refresh` makes it read them again, so call it when you register an invoker after the first binding exists. The example below registers the Avalonia invoker, then asks `ForTarget` about an Avalonia control, a MAUI label and `null`. The answers show which objects the invoker claims.
+
+```csharp
+TextBlock titleLabel = new();
+MauiLabel unclaimed = new();
+AvaloniaViewThreadInvoker invoker = new();
+
+AppLocator.CurrentMutable.RegisterConstant<IViewThreadInvoker>(invoker);
+ViewThreadInvokers.Refresh();
+
+Console.WriteLine(ReferenceEquals(ViewThreadInvokers.ForTarget(titleLabel), invoker));
+Console.WriteLine(ViewThreadInvokers.ForTarget(unclaimed) is null);
+Console.WriteLine(ViewThreadInvokers.ForTarget(null) is null);
+```
+
+```text
+True
+True
+True
+```
+
+`ViewThreadInvokers.ForTarget` returns the first registered invoker that claims an object. It returns `null` when no invoker claims the object, and when the object is `null`. The engine calls it for you, so it is hidden from IntelliSense. The examples after this one run with the Avalonia invoker registered.
+
+**4. Bind as usual.** You write nothing extra in the binding. When the view model changes on the owning thread, the write runs at once and nothing waits. The example below binds a to-do title to a label and changes the title on the UI thread. It prints the label after each step, so you can see the write happen at once.
+
+```csharp
+TextBlock titleLabel = new();
+TodoItem item = new() { Title = OriginalTitle };
+
+using (item.BindOneWay(titleLabel, x => x.Title, x => x.Text))
+{
+    Console.WriteLine(titleLabel.Text);
+
+    item.Title = RenamedTitle;
+
+    Console.WriteLine(titleLabel.Text);
+}
+```
+
+```text
+Renew car registration
+Renew car registration online
+```
+
+**5. Change the value from another thread.** The binding does not write on the worker thread. It holds the value and asks the invoker to post a callback to the owning thread. The label keeps its text until the owning thread runs its queue. In Avalonia, `Dispatcher.UIThread.RunJobs()` runs that queue. The example below changes the title from a worker thread and prints the label before and after the queue runs. The two lines show the write waiting for the owning thread.
+
+```csharp
+TextBlock titleLabel = new();
+TodoItem item = new() { Title = OriginalTitle };
+
+using (item.BindOneWay(titleLabel, x => x.Title, x => x.Text))
+{
+    var worker = new Thread(() => item.Title = FirstSyncedTitle);
+    worker.Start();
+    worker.Join();
+
+    Console.WriteLine(titleLabel.Text);
+
+    Dispatcher.UIThread.RunJobs();
+
+    Console.WriteLine(titleLabel.Text);
+}
+```
+
+```text
+Renew car registration
+Renew car registration (draft)
+```
+
+**6. Change it more than once.** Only the newest value waits. When three values arrive before the owning thread runs, the control receives one write with the last value. The example subscribes to the label's own `Text` changes to count the writes. The first entry is the empty text the label held when the observation started.
+
+```csharp
+TextBlock titleLabel = new();
+TodoItem item = new() { Title = OriginalTitle };
+List<string?> writes = [];
+
+using (titleLabel.WhenChanged(x => x.Text).Subscribe(writes.Add))
+using (item.BindOneWay(titleLabel, x => x.Title, x => x.Text))
+{
+    var worker = new Thread(() =>
+    {
+        item.Title = FirstSyncedTitle;
+        item.Title = SecondSyncedTitle;
+        item.Title = LastSyncedTitle;
+    });
+    worker.Start();
+    worker.Join();
+
+    Dispatcher.UIThread.RunJobs();
+
+    Console.WriteLine(string.Join(" | ", writes.Select(static text => text ?? NoText)));
+}
+```
+
+```text
+(no text) | Renew car registration | Renew car registration (final)
+```
+
+The draft and reviewed titles never reach the label. [Only the newest value waits](#only-the-newest-value-waits) explains why.
+
+## The view thread invoker
+
+### The three members
+
+The invoker answers its three questions from the platform's own API. The example calls each member from the test thread and from a worker thread.
+
+```csharp
+TextBlock titleLabel = new();
+MauiLabel unclaimed = new();
+AvaloniaViewThreadInvoker invoker = new();
+List<string> log = [];
+var accessFromWorker = true;
+
+var worker = new Thread(() => accessFromWorker = invoker.CheckAccess(titleLabel));
+worker.Start();
+worker.Join();
+invoker.Post(titleLabel, static state => ((List<string>)state!).Add(PostedText), log);
+
+Console.WriteLine(invoker.Claims(titleLabel));
+Console.WriteLine(invoker.Claims(unclaimed));
+Console.WriteLine(invoker.CheckAccess(titleLabel));
+Console.WriteLine(accessFromWorker);
+Console.WriteLine(log.Count);
+
+Dispatcher.UIThread.RunJobs();
+
+Console.WriteLine(string.Join(", ", log));
+```
+
+```text
+True
+False
+True
+False
+0
+posted
+```
+
+These rules govern the members:
+
+- `Claims` answers for one platform's types only. It returns `false` for every other object.
+- `CheckAccess` returns `true` on the owning thread. It also returns `true` for an object that has no owning thread, so the binding writes at once.
+- `Post` queues the callback on the owning thread. It must not run the callback on the calling thread, except for an object that has no owning thread.
+- The engine calls `CheckAccess` and `Post` only for an object that `Claims` accepted. The platform invokers throw `InvalidCastException` for any other type.
+
+A platform that has no invoker in the library needs only these three members. The Avalonia invoker above is the whole implementation.
+
+### Find the invoker for a control
+
+`ViewThreadInvokers` holds the registered invokers. It has two members: `Refresh` and `ForTarget`, both shown in step 3. `ForTarget` asks each registered invoker in registration order and returns the first that claims the object. Register one invoker for each platform and keep `Claims` narrow, so the answer does not depend on registration order.
+
+### When no invoker claims the control
+
+A binding that finds no invoker for its target writes on the calling thread. It hands the value straight to the control and does not wait. The control then decides what happens. The example runs before any invoker is registered, so Avalonia refuses the write from the worker thread. The exception reaches the code that changed the view model property.
+
+```csharp
+AvaloniaTodoView view = new();
+TodoItem item = new() { Title = OriginalTitle };
+var failure = string.Empty;
+
+using (item.BindOneWay(view, x => x.Title, v => v.RemainingLabel.Text))
+{
+    var worker = new Thread(() =>
+    {
+        try
+        {
+            item.Title = RenamedTitle;
+        }
+        catch (Exception ex)
+        {
+            failure = ex.GetType().Name;
+        }
+    });
+    worker.Start();
+    worker.Join();
+}
+
+Console.WriteLine(failure);
+```
+
+```text
+InvalidOperationException
+```
+
+For WPF, WinForms and MAUI controls, [the generated binding carries its own invoker](#the-generated-fallback), so this case does not arise for them.
+
+## How a write is delivered
+
+The engine sends each value a binding writes through one stage. The stage follows these rules in order.
+
+1. **Pick the invoker.** The stage uses the first registered invoker that claims the target. A generated binding also carries a fallback invoker for its platform. The stage uses the fallback when no registered invoker claims the target. With no invoker at all, the source passes through unchanged.
+2. **Write at once when it is safe.** A notification runs inline on the calling thread when no value is waiting and `CheckAccess` returns `true`.
+3. **Otherwise wait.** The stage holds the notification and schedules one drain. The drain writes what waits. It runs on `BindingSchedulers.MainThread` when that property is set. Otherwise it runs through the invoker's `Post`.
+
+### Only the newest value waits
+
+The stage keeps one slot for a waiting value. A newer value replaces the one in the slot. That holds even for a value raised on the owning thread while a drain runs. The drain loops until the slot is empty. An error or the end of the stream waits beside the value and reaches the observer after it.
+
+The engine keeps only the newest value because of two-way bindings. Writing a view raises the view's own change at once. If an older value were waiting, that echo would write the older value back to the view model. The write would raise another change, and the two sides would bounce forever. Disposing the subscription drops the waiting value.
+
+`WitnessLatestOn` applies the same rule to a stream you own. It comes from ReactiveUI.Primitives and takes a sequencer. The [observing](observing.md) page uses it on a `WhenChanged` stream. The operator builds a `WitnessLatestOnSignal<T>`. Its subscription keeps one pending value under a lock. Each new value overwrites the pending one. The subscription asks the sequencer for a single drain, and each drain delivers the newest value. An error or completion waits behind the pending value. The plain `WitnessOn` operator delivers every value instead.
+
+The binding engine keeps this rule in its own stage, `ViewThreadObservable`, because the stage also has the inline path from rule 2. The two differ in one way. `WitnessLatestOn` always goes through its sequencer. The engine's stage writes inline on the owning thread when nothing waits.
+
+## Choose where waiting writes run
+
+`BindingSchedulers` sets where a waiting write runs. A **sequencer** is an `ISequencer` from ReactiveUI.Primitives: an object that decides when and on which thread queued work runs. `BindingSchedulers` has one property, three routing methods and one helper.
+
+| Member | What it does |
+|--------|--------------|
+| `MainThread` | The sequencer that runs a waiting write for an object an invoker claims. `null` uses the invoker's `Post`. |
+| `UseSynchronizationContext` | Sets `MainThread` from a `SynchronizationContext`. `null` clears it. |
+| `ObserveOnViewThread` | Routes a stream onto the thread that owns a control, with the registered invokers. One overload takes a fallback invoker. |
+| `ObserveOnSequencer` | Routes a stream onto a sequencer, so that only the newest waiting value is delivered. |
+
+The three routing methods are for generated code and are hidden from IntelliSense. The sections below show what each one does.
+
+### Run waiting writes on the UI sequencer
+
+By default the invoker's `Post` runs a waiting write. Set `BindingSchedulers.MainThread` when your application has a sequencer for its UI thread. The Avalonia example uses `AvaloniaScheduler.Instance` from the `ReactiveUI.Primitives.Avalonia` package.
+
+`AvaloniaScheduler` implements `ISequencer` on top of Avalonia's dispatcher. `Instance` is the shared scheduler for `Dispatcher.UIThread`. It posts to the dispatcher at `DispatcherPriority.Background`. You can build your own with `new AvaloniaScheduler(dispatcher)` or `new AvaloniaScheduler(dispatcher, priority)`. The scheduler batches queued work into one dispatcher drain and runs it without reentrancy.
+
+The two objects have separate jobs. The invoker decides **who** a write belongs to and whether the calling thread may write. The sequencer decides **where and when** a waiting write runs. The engine reads `MainThread` each time it schedules a drain, so a change applies to existing bindings. Set it once at start-up. If a test sets it, clear it in a `finally` block, as the examples do.
+
+The example below sets `MainThread` to the shared Avalonia scheduler and changes the title from a worker thread. It prints the label before and after the queue runs, so you can see that the sequencer delivers the write.
+
+```csharp
+TextBlock titleLabel = new();
+TodoItem item = new() { Title = OriginalTitle };
+var sequencer = AvaloniaScheduler.Instance;
+BindingSchedulers.MainThread = sequencer;
+
+try
+{
+    using (item.BindOneWay(titleLabel, x => x.Title, x => x.Text))
+    {
+        var worker = new Thread(() => item.Title = SyncedTitle);
+        worker.Start();
+        worker.Join();
+
+        Console.WriteLine(ReferenceEquals(BindingSchedulers.MainThread, sequencer));
+        Console.WriteLine(titleLabel.Text);
+
+        Dispatcher.UIThread.RunJobs();
+
+        Console.WriteLine(titleLabel.Text);
+    }
+}
+finally
+{
+    BindingSchedulers.MainThread = null;
+}
+```
+
+```text
+True
+Renew car registration
+Renew car registration (reviewed)
+```
+
+`MainThread` only carries writes from another thread to an object an invoker claims. It never sees a write on the owning thread, because there is nothing to carry. The example below sets `MainThread` and then changes the title on the UI thread. The label updates at once, which shows the sequencer is not involved.
+
+```csharp
+TextBlock titleLabel = new();
+TodoItem item = new() { Title = OriginalTitle };
+BindingSchedulers.MainThread = AvaloniaScheduler.Instance;
+
+try
+{
+    using (item.BindOneWay(titleLabel, x => x.Title, x => x.Text))
+    {
+        item.Title = RenamedTitle;
+
+        Console.WriteLine(titleLabel.Text);
+    }
+}
+finally
+{
+    BindingSchedulers.MainThread = null;
+}
+```
+
+```text
+Renew car registration online
+```
+
+`MainThread` never sees a write to an object that no invoker claims either. The write runs on the thread that raised it. This example binds a MAUI `Label`, which the Avalonia invoker does not claim. The write from the worker thread reaches the label at once, before any dispatcher runs.
+
+```csharp
+MauiLabel titleLabel = new();
+TodoItem item = new() { Title = OriginalTitle };
+BindingSchedulers.MainThread = AvaloniaScheduler.Instance;
+
+try
+{
+    using (item.BindOneWay(titleLabel, x => x.Title, x => x.Text))
+    {
+        var worker = new Thread(() => item.Title = SyncedTitle);
+        worker.Start();
+        worker.Join();
+
+        Console.WriteLine(titleLabel.Text);
+    }
+}
+finally
+{
+    BindingSchedulers.MainThread = null;
+}
+```
+
+```text
+Renew car registration (reviewed)
+```
+
+### Use a synchronization context
+
+A **synchronization context** is a .NET object that queues work back onto a particular thread. `SynchronizationContext.Current` returns the one for the calling thread. `UseSynchronizationContext` wraps a context in a `SynchronizationContextSequencer` and sets it as `MainThread`. Passing `null` sets `MainThread` back to `null`, so writes return to the invoker's `Post`. See [`SynchronizationContext`](https://learn.microsoft.com/dotnet/api/system.threading.synchronizationcontext) for the type itself.
+
+The example below sets the current context as `MainThread`, changes the title from a worker thread and clears the setting at the end. The write waits for the UI queue, as it does with a sequencer.
+
+```csharp
+TextBlock titleLabel = new();
+TodoItem item = new() { Title = OriginalTitle };
+BindingSchedulers.UseSynchronizationContext(SynchronizationContext.Current);
+
+try
+{
+    Console.WriteLine(BindingSchedulers.MainThread is SynchronizationContextSequencer);
+
+    using (item.BindOneWay(titleLabel, x => x.Title, x => x.Text))
+    {
+        var worker = new Thread(() => item.Title = SyncedTitle);
+        worker.Start();
+        worker.Join();
+
+        Console.WriteLine(titleLabel.Text);
+
+        Dispatcher.UIThread.RunJobs();
+
+        Console.WriteLine(titleLabel.Text);
+    }
+}
+finally
+{
+    BindingSchedulers.UseSynchronizationContext(null);
+}
+
+Console.WriteLine(BindingSchedulers.MainThread is null);
+```
+
+```text
+True
+Renew car registration
+Renew car registration (reviewed)
+True
+```
+
+### Route your own stream
+
+Generated bindings call the routing methods for you. You can call them on a stream you write to a control yourself. `ObserveOnViewThread` takes the stream and the control. It returns the stream itself when the control is `null` or no registered invoker claims it. Otherwise it returns the stream routed with the rules above. The example below routes a `WhenChanged` stream to a label and raises a change from a worker thread. It prints what the subscriber holds before and after the queue runs, to show that delivery waits for the owning thread.
+
+```csharp
+TextBlock titleLabel = new();
+TodoItem item = new() { Title = OriginalTitle };
+List<string> delivered = [];
+
+var routed = BindingSchedulers.ObserveOnViewThread(item.WhenChanged(x => x.Title), titleLabel);
+
+using (routed.Subscribe(delivered.Add))
+{
+    var worker = new Thread(() => item.Title = SyncedTitle);
+    worker.Start();
+    worker.Join();
+
+    Console.WriteLine(string.Join(", ", delivered));
+
+    Dispatcher.UIThread.RunJobs();
+
+    Console.WriteLine(string.Join(", ", delivered));
+}
+```
+
+```text
+Renew car registration
+Renew car registration, Renew car registration (reviewed)
+```
+
+A value that another thread raises reaches the subscriber only after the owning thread runs its queue. The first line shows the values the subscriber had when the worker thread finished. The second line shows them after `Dispatcher.UIThread.RunJobs()` runs the queue.
+
+The overload with a `fallback` parameter uses that invoker when no registered invoker claims the control. It returns the stream itself only when the control is `null`, and it throws `ArgumentNullException` for a `null` stream or fallback. Generated code passes the platform's fallback here. The example below passes `new AvaloniaViewThreadInvoker()` as the fallback. The registered invoker claims the label, so the fallback goes unused and the output matches the previous example.
+
+```csharp
+TextBlock titleLabel = new();
+TodoItem item = new() { Title = OriginalTitle };
+AvaloniaViewThreadInvoker fallback = new();
+List<string> delivered = [];
+
+var routed = BindingSchedulers.ObserveOnViewThread(item.WhenChanged(x => x.Title), titleLabel, fallback);
+
+using (routed.Subscribe(delivered.Add))
+{
+    var worker = new Thread(() => item.Title = SyncedTitle);
+    worker.Start();
+    worker.Join();
+
+    Console.WriteLine(string.Join(", ", delivered));
+
+    Dispatcher.UIThread.RunJobs();
+
+    Console.WriteLine(string.Join(", ", delivered));
+}
+```
+
+```text
+Renew car registration
+Renew car registration, Renew car registration (reviewed)
+```
+
+`ObserveOnSequencer` routes a stream onto a sequencer. A delivery on a sequencer never runs inline. Every value waits for the sequencer, and a newer value replaces one that has not been delivered. The example below changes the title twice on the UI thread. It prints how many values arrived before the queue ran, then the values after, so you can see that only the newer title is delivered.
+
+```csharp
+TodoItem item = new() { Title = OriginalTitle };
+var sequencer = AvaloniaScheduler.Instance;
+List<string> delivered = [];
+
+var routed = BindingSchedulers.ObserveOnSequencer(item.WhenChanged(x => x.Title), sequencer);
+
+using (routed.Subscribe(delivered.Add))
+{
+    item.Title = DraftTitle;
+    item.Title = SyncedTitle;
+
+    Console.WriteLine(delivered.Count);
+
+    Dispatcher.UIThread.RunJobs();
+
+    Console.WriteLine(string.Join(", ", delivered));
+}
+```
+
+```text
+0
+Renew car registration (reviewed)
+```
+
+## Deliver a binding on a sequencer
+
+The property-binding APIs `BindOneWay`, `BindTwoWay`, `OneWayBind` and `Bind` have overloads that take an `ISequencer`. The sequencer follows the property lambdas and any conversion arguments. The binding then delivers each write through `ObserveOnSequencer`. The first write waits too. These examples use `VirtualClock` from ReactiveUI.Primitives. It queues work and runs it only when you call `Start()`, so the examples show each step. In an application you pass the sequencer for your UI thread.
+
+The example below binds a title to a MAUI label on a `VirtualClock`. It prints the label before the first `Start()`, after it and after a later edit. Every write, even the first, waits for the sequencer.
+
+```csharp
+Label titleLabel = new();
+TodoItem item = new() { Title = OriginalTitle };
+VirtualClock sequencer = new();
+
+using (item.BindOneWay(titleLabel, x => x.Title, x => x.Text, sequencer))
+{
+    Console.WriteLine(titleLabel.Text ?? NoText);
+
+    sequencer.Start();
+
+    Console.WriteLine(titleLabel.Text);
+
+    item.Title = RenamedTitle;
+
+    Console.WriteLine(titleLabel.Text);
+
+    sequencer.Start();
+
+    Console.WriteLine(titleLabel.Text);
+}
+```
+
+```text
+(no text)
+Renew car registration
+Renew car registration
+Renew car registration online
+```
+
+A two-way binding sends both directions through the sequencer. Two edits before the sequencer runs write once, with the second value. The binding does not replay the first edit. The example below edits the reference twice before the sequencer runs and prints both sides. Both show the second value.
+
+```csharp
+Entry referenceBox = new();
+TransferDraft draft = new() { Reference = RentReference };
+VirtualClock sequencer = new();
+
+using (draft.BindTwoWay(referenceBox, x => x.Reference, x => x.Text, sequencer))
+{
+    sequencer.Start();
+
+    draft.Reference = RentAprilReference;
+    draft.Reference = RentMayReference;
+    sequencer.Start();
+
+    Console.WriteLine(referenceBox.Text);
+    Console.WriteLine(draft.Reference);
+}
+```
+
+```text
+Rent May
+Rent May
+```
+
+A conversion function or a converter goes before the sequencer. The example below formats the amount as text for the view and parses the text back for the view model. Each direction runs through the sequencer.
+
+```csharp
+Entry amountBox = new();
+TransferDraft draft = new() { Amount = RentAmount };
+VirtualClock sequencer = new();
+
+using (draft.BindTwoWay(
+    amountBox,
+    x => x.Amount,
+    x => x.Text,
+    static amount => amount.ToString(TwoDecimalPlaces, CultureInfo.InvariantCulture),
+    ParseAmount,
+    sequencer))
+{
+    sequencer.Start();
+
+    Console.WriteLine(amountBox.Text);
+
+    amountBox.Text = RaisedRentAmountText;
+    sequencer.Start();
+
+    Console.WriteLine(draft.Amount);
+}
+```
+
+```text
+1200.00
+1250.50
+```
+
+A converter also takes an optional hint, such as a format string. The example below passes a converter and the format `F2` as the hint, so the amount shows two decimal places once the sequencer runs.
+
+```csharp
+Entry amountBox = new();
+TransferDraft draft = new() { Amount = RentAmount };
+VirtualClock sequencer = new();
+
+using (draft.BindOneWay(amountBox, x => x.Amount, x => x.Text, new DecimalToStringTypeConverter(), TwoDecimalPlaces, sequencer))
+{
+    sequencer.Start();
+
+    Console.WriteLine(amountBox.Text);
+}
+```
+
+```text
+1200.00
+```
+
+`SequencerExamples.cs` in the example project has a method for every shape below. A scheduler argument of `null` means the binding writes on the thread that owns the target, as if you had named no scheduler.
+
+| API | Sequencer overloads | Example method |
+|-----|---------------------|----------------|
+| `BindOneWay` | property, conversion function, converter with hint | `BindOneWayOnSequencer`, `BindOneWayWithConversionOnSequencerAsync`, `BindOneWayWithConverterOnSequencer` |
+| `BindTwoWay` | property, two conversion functions, two converters with hint | `BindTwoWayOnSequencer`, `BindTwoWayBurstOnSequencer`, `BindTwoWayWithConversionOnSequencer`, `BindTwoWayWithConvertersOnSequencer` |
+| `OneWayBind` | selector, converter with hint | `OneWayBindViewOnSequencerAsync`, `OneWayBindViewWithConverterOnSequencer` |
+| `Bind` | two conversion functions, two converters with hint | `BindViewOnSequencer`, `BindViewWithConvertersOnSequencer` |
+| `BindOneWayUnsafe`, `BindTwoWayUnsafe`, `OneWayBindUnsafe`, `BindUnsafe` | the same shapes, resolved at run time | `BindOneWayUnsafeOnSequencer` and the other `Unsafe` methods in the same file |
+
+The `Unsafe` overloads are covered in [unsafe](unsafe.md). The [bindings](bindings.md) page covers the calls themselves and [converters](converters.md) covers converters and hints.
+
+## The platform modules
+
+The library ships a view thread invoker for WPF, WinForms and MAUI. Each comes from a platform package and a module that registers it.
+
+| Platform | Builder call and module | Invoker | `Claims` | `CheckAccess` | `Post` |
+|----------|-------------------------|---------|----------|---------------|--------|
+| WPF (Windows) | `WithWpf`, `WpfBindingModule` | `Wpf.DispatcherViewThreadInvoker` | `DispatcherObject` | `DispatcherObject.CheckAccess()` | `Dispatcher.BeginInvoke` at normal priority. Runs inline when the object has no dispatcher. |
+| WinForms (Windows) | `WithWinForms`, `WinFormsBindingModule` | `WinForms.ControlViewThreadInvoker` | `Control` | `!Control.InvokeRequired` | `Control.BeginInvoke`. Runs inline while no invoke is required. |
+| MAUI (any OS) | `WithMaui`, `MauiBindingModule` | `Maui.DispatcherViewThreadInvoker` | `BindableObject` | `!IDispatcher.IsDispatchRequired` | `IDispatcher.Dispatch`. Runs inline when the object has no dispatcher. |
+
+The WPF and WinForms modules also register an observer for their platform's properties. The MAUI module also registers the two Visibility converters. [Setup](setup.md) covers the builder. Each `With` method returns the builder it was called on, so you can chain it, and each is available on `IAppBuilder` and on `IReactiveUIBindingBuilder`.
+
+The example below builds an app with the MAUI module. It checks that the invoker and both converters are registered, and that the converter service holds the converters only after `ImportFrom`.
+
+```csharp
+var builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+var app = builder.WithCoreServices().WithMaui().BuildApp();
+ViewThreadInvokers.Refresh();
+var converters = app.Current!.GetServices<IBindingTypeConverter>().ToArray();
+
+Console.WriteLine(app.Current!.GetServices<IViewThreadInvoker>().OfType<DispatcherViewThreadInvoker>().Any());
+Console.WriteLine(converters.OfType<BooleanToVisibilityTypeConverter>().Any());
+Console.WriteLine(converters.OfType<VisibilityToBooleanTypeConverter>().Any());
+Console.WriteLine(builder.ConverterService.TypedConverters.TryGetConverter(typeof(bool), typeof(Visibility)) is null);
+
+builder.ConverterService.ImportFrom(app.Current!);
+
+Console.WriteLine(BindingConverters.Current.TypedConverters.TryGetConverter(typeof(bool), typeof(Visibility)) is BooleanToVisibilityTypeConverter);
+Console.WriteLine(BindingConverters.Current.TypedConverters.TryGetConverter(typeof(Visibility), typeof(bool)) is VisibilityToBooleanTypeConverter);
+```
+
+```text
+True
+True
+True
+True
+True
+True
+```
+
+The MAUI module registers the invoker and both Visibility converters with the dependency resolver. The converter service does not hold the converters until `ImportFrom` copies them in, which the example shows. Call `ViewThreadInvokers.Refresh` after `BuildApp`, as the example does, when a binding has run.
+
+You can apply a module to a resolver you own, without the builder. Create the module and call its `Configure` method with the resolver. The example below applies the module to a new resolver and checks what it registered. The invoker and both converters appear in the resolver.
+
+```csharp
+using ModernDependencyResolver resolver = new();
+MauiBindingModule module = new();
+
+module.Configure(resolver);
+
+var converters = resolver.GetServices<IBindingTypeConverter>().ToArray();
+
+Console.WriteLine(resolver.GetServices<IViewThreadInvoker>().OfType<DispatcherViewThreadInvoker>().Any());
+Console.WriteLine(converters.OfType<BooleanToVisibilityTypeConverter>().Any());
+Console.WriteLine(converters.OfType<VisibilityToBooleanTypeConverter>().Any());
+```
+
+```text
+True
+True
+True
+```
+
+The builder calls chain from either builder type. The first example holds the builder as `IAppBuilder`. It checks that `WithMaui` returns the same builder, so calls can keep chaining.
+
+```csharp
+using ModernDependencyResolver resolver = new();
+IAppBuilder appBuilder = resolver.CreateReactiveUIBindingBuilder();
+
+var chained = appBuilder.WithMaui();
+
+Console.WriteLine(ReferenceEquals(appBuilder, chained));
+```
+
+```text
+True
+```
+
+The second example holds the builder as `IReactiveUIBindingBuilder` and checks the same for `WithWpf`.
+
+```csharp
+using ModernDependencyResolver resolver = new();
+var builder = (IReactiveUIBindingBuilder)resolver.CreateReactiveUIBindingBuilder();
+
+var chained = builder.WithWpf();
+
+Console.WriteLine(ReferenceEquals(builder, chained));
+```
+
+```text
+True
+```
+
+`WinFormsExamples.cs` and `WpfExamples.cs` hold the same checks for `WithWinForms`, `WithWpf`, `WinFormsBindingModule` and `WpfBindingModule`.
+
+### The generated fallback
+
+A binding the generator writes does not need the module to move its writes. The generator checks the type of the target while it reads the binding. It matches `System.Windows.Threading.DispatcherObject`, `System.Windows.Forms.Control` and `Microsoft.Maui.Controls.BindableObject`. The generated binding then carries the invoker for that platform as its fallback. `BindTo`, `BindOneWay`, `OneWayBind` and `Bind` do this for the target. `BindTwoWay` does it for both sides. `BindCommand` does it for the view.
+
+The generator declares the fallback classes in `ViewThreadInvokers.g.cs`, once per compilation. It declares a class only when the platform type resolves in the compilation, so every generated reference has a declaration. There is no WinUI invoker, so a WinUI or Avalonia target needs an invoker you register.
+
+The first example follows an upload whose progress arrives on a pool thread. It runs without a module, so `ForTarget` finds nothing. The write reaches the progress bar on its owning thread, because the generated binding carries the WPF invoker.
+
+```csharp
+WpfUploadWindow view = new();
+
+Console.WriteLine(ViewThreadInvokers.ForTarget(view.UploadProgressBar) is null);
+
+await RunUploadFromWorkerThreadAsync(view);
+```
+
+```text
+True
+100
+```
+
+The second example runs the same upload after `BuildWpfApplication` registers the WPF module. The first line shows that `ForTarget` returns the registered invoker for the bar, and the progress arrives the same way.
+
+```csharp
+WpfUploadWindow view = new();
+
+Console.WriteLine(ViewThreadInvokers.ForTarget(view.UploadProgressBar) is DispatcherViewThreadInvoker);
+
+await RunUploadFromWorkerThreadAsync(view);
+```
+
+```text
+True
+100
+```
+
+The registered invoker matters for the `Unsafe` binding APIs. They resolve the target at run time and have no generated fallback, so they move a write only when a platform module or your own registration supplies the invoker.
+
+### Avalonia
+
+Avalonia has no module in the library. The invoker from the walkthrough is the whole integration. With it registered, a progress report from a pool thread waits for the UI thread. The example below binds an upload's progress to a progress bar. The upload reports progress from pool threads, and the registered invoker moves each write to the UI thread.
+
+```csharp
+StorageBrowserViewModel viewModel = new(InMemoryObjectStorage.CreateSeeded());
+await viewModel.LoadBucketsAsync();
+viewModel.SelectedBucket = viewModel.Buckets[0];
+AvaloniaUploadView view = new() { ViewModel = viewModel };
+UploadRequest photo = new(OffsitePhotoName, OffsitePhotoSize, JpegType);
+
+using (viewModel.BindOneWay(view, x => x.UploadPercent, v => v.UploadProgressBar.Value))
+{
+    Console.WriteLine(view.UploadProgressBar.Value);
+
+    await viewModel.UploadAsync(photo);
+
+    Console.WriteLine(view.UploadProgressBar.Value);
+}
+```
+
+```text
+0
+100
+```
+
+An Avalonia control raises `PropertyChanged` with the name of the property. That is the notification the engine observes, so `WhenChanged` works on Avalonia controls without more setup. The example below subscribes to the control's own `PropertyChanged` event and prints the property name it raises. It shows the notification the engine relies on.
+
+```csharp
+AvaloniaTodoView view = new();
+var notifying = (INotifyPropertyChanged)view.FilterTextBox;
+notifying.PropertyChanged += static (_, e) => Console.WriteLine(e.PropertyName);
+
+view.FilterTextBox.Text = CarFilter;
+```
+
+```text
+Text
+```
+
+`WhenChanged` observes that event. The example below observes `Text` and sets the text once. The first value is the empty text the box held when the observation started, and the second is the new text.
+
+```csharp
+AvaloniaTodoView view = new();
+List<string?> texts = [];
+
+using (view.FilterTextBox.WhenChanged(x => x.Text).Subscribe(texts.Add))
+{
+    view.FilterTextBox.Text = CarFilter;
+}
+
+Console.WriteLine(string.Join(", ", texts));
+```
+
+```text
+, car
+```
+
+### WPF
+
+WPF controls are `DispatcherObject` instances, and each belongs to one dispatcher. `CheckAccess` asks that dispatcher. `Post` queues the callback on it, and the callback runs when the dispatcher drains. A frozen `Freezable`, such as a frozen brush, belongs to no thread and has no dispatcher. `Post` runs the callback at once for it. This example calls the three members from the UI thread and a worker thread. The worker thread may not write, and its posted callback runs when the dispatcher drains.
+
+```csharp
+DispatcherViewThreadInvoker invoker = new();
+WpfUploadWindow view = new();
+var progressBar = view.UploadProgressBar;
+List<string> log = [];
+object unclaimed = new();
+var accessFromWorker = true;
+
+var worker = new Thread(() =>
+{
+    accessFromWorker = invoker.CheckAccess(progressBar);
+    invoker.Post(progressBar, static state => ((List<string>)state!).Add(PostedText), log);
+});
+worker.Start();
+worker.Join();
+
+Console.WriteLine(invoker.Claims(progressBar));
+Console.WriteLine(invoker.Claims(unclaimed));
+Console.WriteLine(invoker.CheckAccess(progressBar));
+Console.WriteLine(accessFromWorker);
+Console.WriteLine(log.Count);
+
+progressBar.Dispatcher.Invoke(static () => { }, DispatcherPriority.Background);
+
+Console.WriteLine(string.Join(", ", log));
+```
+
+```text
+True
+False
+True
+False
+0
+posted
+```
+
+The example below posts a callback to a frozen brush, which has no dispatcher. The callback runs before `Post` returns, so a frozen object never waits for a thread that does not exist.
+
+```csharp
+DispatcherViewThreadInvoker invoker = new();
+SolidColorBrush brush = new(Colors.Green);
+brush.Freeze();
+List<string> log = [];
+
+invoker.Post(brush, static state => ((List<string>)state!).Add(PostedText), log);
+
+Console.WriteLine(string.Join(", ", log));
+```
+
+```text
+posted
+```
+
+A `null` callback throws `ArgumentNullException`, as it does in every platform invoker. The example below passes `null` to `Post` and records the exception. The invoker rejects the missing callback at once instead of failing later on the UI thread.
+
+```csharp
+DispatcherViewThreadInvoker invoker = new();
+WpfUploadWindow view = new();
+var rejected = false;
+
+try
+{
+    invoker.Post(view.UploadProgressBar, null!, null);
+}
+catch (ArgumentNullException)
+{
+    rejected = true;
+}
+
+Console.WriteLine(rejected);
+```
+
+```text
+True
+```
+
+WPF also refuses a write from a thread that does not own the control. The example below sets a progress bar value from a worker thread. The exception and the unchanged value show what a binding has to avoid.
+
+```csharp
+WpfUploadWindow view = new();
+var refused = false;
+
+var worker = new Thread(() =>
+{
+    try
+    {
+        view.UploadProgressBar.Value = FullPercent;
+    }
+    catch (InvalidOperationException)
+    {
+        refused = true;
+    }
+});
+worker.Start();
+worker.Join();
+
+Console.WriteLine(refused);
+Console.WriteLine(view.UploadProgressBar.Value);
+```
+
+```text
+True
+0
+```
+
+The WPF module registers the dependency-property observer and the invoker. It adds no Visibility converter. Register both converters yourself with `WithConverter`. The example below shows that the converter service has no Visibility converters after `WithWpf`. It then registers both converters and checks that the observer, the invoker and the converters are all in place.
+
+```csharp
+var builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+_ = builder.WithCoreServices().WithWpf();
+
+Console.WriteLine(builder.ConverterService.TypedConverters.TryGetConverter(typeof(bool), typeof(Visibility)) is null);
+Console.WriteLine(builder.ConverterService.TypedConverters.TryGetConverter(typeof(Visibility), typeof(bool)) is null);
+
+var app = builder
+    .WithConverter(new BooleanToVisibilityTypeConverter())
+    .WithConverter(new VisibilityToBooleanTypeConverter())
+    .BuildApp();
+ViewThreadInvokers.Refresh();
+
+Console.WriteLine(app.Current!.GetServices<ICreatesObservableForProperty>().OfType<DependencyObjectObservableForProperty>().Any());
+Console.WriteLine(app.Current!.GetServices<IViewThreadInvoker>().OfType<DispatcherViewThreadInvoker>().Any());
+Console.WriteLine(BindingConverters.Current.TypedConverters.TryGetConverter(typeof(bool), typeof(Visibility)) is BooleanToVisibilityTypeConverter);
+Console.WriteLine(BindingConverters.Current.TypedConverters.TryGetConverter(typeof(Visibility), typeof(bool)) is VisibilityToBooleanTypeConverter);
+```
+
+```text
+True
+True
+True
+True
+True
+True
+```
+
+`DependencyObjectObservableForProperty` observes a property when the control declares it as a dependency property. It reports an affinity of 4 for those properties and 0 for anything else. See [mechanisms](mechanisms.md) for what an affinity is. The example below asks the provider about `Text` on a `TextBox`, once for each value of the last argument. It also asks about a property that does not exist and about a type that is not a dependency object.
+
+```csharp
+DependencyObjectObservableForProperty provider = new();
+
+Console.WriteLine(provider.GetAffinityForObject(typeof(TextBox), TextPropertyName, false));
+Console.WriteLine(provider.GetAffinityForObject(typeof(TextBox), TextPropertyName, true));
+Console.WriteLine(provider.GetAffinityForObject(typeof(TextBox), "Missing", false));
+Console.WriteLine(provider.GetAffinityForObject(typeof(TodoItem), "Title", false));
+```
+
+```text
+4
+4
+0
+0
+```
+
+The provider raises after each change and carries no value, so the subscriber reads the property. The example below subscribes, sets the text twice and reads the text in each notification. It sets the text a third time after the subscription ends, and that change is not recorded.
+
+```csharp
+DependencyObjectObservableForProperty provider = new();
+WpfTodoWindow view = new();
+var expression = Expression.Constant(view.FilterTextBox);
+List<string> texts = [];
+
+using (provider.GetNotificationForProperty(view.FilterTextBox, expression, TextPropertyName, false, false).Subscribe(change => texts.Add(((TextBox)change.Sender).Text)))
+{
+    view.FilterTextBox.Text = CarFilter;
+    view.FilterTextBox.Text = CarsFilter;
+}
+
+view.FilterTextBox.Text = CarFilter;
+
+Console.WriteLine(string.Join(", ", texts));
+```
+
+```text
+car, cars
+```
+
+The provider throws `ArgumentException` for a property the control has no dependency property for. The example below asks for a property called `Missing` and records the exception, so a wrong property name fails when you ask for the notification.
+
+```csharp
+DependencyObjectObservableForProperty provider = new();
+WpfTodoWindow view = new();
+var expression = Expression.Constant(view.FilterTextBox);
+var rejected = false;
+
+try
+{
+    _ = provider.GetNotificationForProperty(view.FilterTextBox, expression, "Missing", false, false);
+}
+catch (ArgumentException)
+{
+    rejected = true;
+}
+
+Console.WriteLine(rejected);
+```
+
+```text
+True
+```
+
+`WhenChanged` reads the dependency property at build time. The example below observes `Text` on a WPF text box and sets it once. The result matches the Avalonia example, so the same code works on both platforms.
+
+```csharp
+WpfTodoWindow view = new();
+List<string> texts = [];
+
+using (view.FilterTextBox.WhenChanged(x => x.Text).Subscribe(texts.Add))
+{
+    view.FilterTextBox.Text = CarFilter;
+}
+
+Console.WriteLine(string.Join(", ", texts));
+```
+
+```text
+, car
+```
+
+`ViewModel` on a WPF view is a dependency property too, so `WhenChanged` can keep `DataContext` in step with it. The example below pipes the view's `ViewModel` into its `DataContext`. The first line shows `DataContext` empty, and the second shows it holds the view model after you set it.
+
+```csharp
+WpfTodoWindow view = new();
+TodoListViewModel viewModel = new(InMemoryTodoStore.CreateSeeded());
+
+using (view.WhenChanged(x => x.ViewModel).BindTo(view, x => x.DataContext))
+{
+    Console.WriteLine(view.DataContext is null);
+
+    view.ViewModel = viewModel;
+
+    Console.WriteLine(ReferenceEquals(view.DataContext, viewModel));
+}
+```
+
+```text
+True
+True
+```
+
+### WinForms
+
+A WinForms `Control` has an owning thread only after it has a window handle. Before that, `InvokeRequired` is `false`, so the invoker lets any thread write and runs a posted callback at once. The first example below uses a control that has no handle. A worker thread may write, and the posted callback runs before `Post` returns. After the handle exists, `CheckAccess` is `false` on a worker thread and `Post` waits for the message loop.
+
+```csharp
+ControlViewThreadInvoker invoker = new();
+using WinFormsUploadForm view = new();
+List<string> log = [];
+var accessFromWorker = false;
+
+var worker = new Thread(() => accessFromWorker = invoker.CheckAccess(view.UploadProgressBar));
+worker.Start();
+worker.Join();
+invoker.Post(view.UploadProgressBar, static state => ((List<string>)state!).Add(PostedText), log);
+
+Console.WriteLine(accessFromWorker);
+Console.WriteLine(string.Join(", ", log));
+```
+
+```text
+True
+posted
+```
+
+This example creates the handle first. The worker thread may not write, and the posted callback waits until the message loop runs.
+
+```csharp
+ControlViewThreadInvoker invoker = new();
+using WinFormsUploadForm view = new();
+var progressBar = view.UploadProgressBar;
+_ = progressBar.Handle;
+List<string> log = [];
+object unclaimed = new();
+var accessFromWorker = true;
+
+var worker = new Thread(() =>
+{
+    accessFromWorker = invoker.CheckAccess(progressBar);
+    invoker.Post(progressBar, static state => ((List<string>)state!).Add(PostedText), log);
+});
+worker.Start();
+worker.Join();
+
+Console.WriteLine(invoker.Claims(progressBar));
+Console.WriteLine(invoker.Claims(unclaimed));
+Console.WriteLine(invoker.CheckAccess(progressBar));
+Console.WriteLine(accessFromWorker);
+Console.WriteLine(log.Count);
+
+Application.DoEvents();
+
+Console.WriteLine(string.Join(", ", log));
+```
+
+```text
+True
+False
+True
+False
+0
+posted
+```
+
+A `null` callback throws `ArgumentNullException`, as it does in every platform invoker. The example below passes `null` to `Post` and records the exception. The invoker rejects the missing callback at once instead of failing later on the UI thread.
+
+```csharp
+ControlViewThreadInvoker invoker = new();
+using WinFormsUploadForm view = new();
+var rejected = false;
+
+try
+{
+    invoker.Post(view.UploadProgressBar, null!, null);
+}
+catch (ArgumentNullException)
+{
+    rejected = true;
+}
+
+Console.WriteLine(rejected);
+```
+
+```text
+True
+```
+
+When `Control.CheckForIllegalCrossThreadCalls` is `true`, WinForms refuses a write from a thread that does not own the control. The example below turns the check on and sets a progress bar value from a worker thread. The exception shows the call that the invoker keeps a binding from making.
+
+```csharp
+using WinFormsUploadForm view = new();
+_ = view.UploadProgressBar.Handle;
+var refused = false;
+Control.CheckForIllegalCrossThreadCalls = true;
+
+var worker = new Thread(() =>
+{
+    try
+    {
+        view.UploadProgressBar.Value = FullPercent;
+    }
+    catch (InvalidOperationException)
+    {
+        refused = true;
+    }
+});
+worker.Start();
+worker.Join();
+
+Console.WriteLine(refused);
+```
+
+```text
+True
+```
+
+The WinForms module registers the event-based observer and the control invoker. `WinFormsCreatesObservableForProperty` follows a public `{Name}Changed` event on a component, such as `TextChanged` for `Text`. It reports an affinity of 8 for a property that has one, and 0 otherwise. Read the [mechanisms](mechanisms.md) page for how the affinity picks between observers. The example below builds an app with the WinForms module and checks that the observer and the invoker are registered.
+
+```csharp
+var app = RxBindingBuilder.CreateReactiveUIBindingBuilder()
+    .WithCoreServices()
+    .WithWinForms()
+    .BuildApp();
+ViewThreadInvokers.Refresh();
+
+Console.WriteLine(app.Current!.GetServices<ICreatesObservableForProperty>().OfType<WinFormsCreatesObservableForProperty>().Any());
+Console.WriteLine(app.Current!.GetServices<IViewThreadInvoker>().OfType<ControlViewThreadInvoker>().Any());
+```
+
+```text
+True
+True
+```
+
+The affinity is 8 for `Text` on a `TextBox`, `Checked` on a `CheckBox`, and `DataSource`, `SelectedValue` and `SelectedIndex` on a `ListBox`. It is 0 for `SelectedItem`, which has no `SelectedItemChanged` event, so bind `SelectedValue` or `SelectedIndex` instead. The observer raises only after a change, so it returns 0 when you ask for a before-change notification. The example below asks the observer about several properties, one before-change request, a missing property and a view-model type. The numbers show which ones it accepts.
+
+```csharp
+WinFormsCreatesObservableForProperty observer = new();
+
+Console.WriteLine(observer.GetAffinityForObject(typeof(TextBox), TextPropertyName, false));
+Console.WriteLine(observer.GetAffinityForObject(typeof(CheckBox), "Checked", false));
+Console.WriteLine(observer.GetAffinityForObject(typeof(ListBox), "DataSource", false));
+Console.WriteLine(observer.GetAffinityForObject(typeof(ListBox), "SelectedValue", false));
+Console.WriteLine(observer.GetAffinityForObject(typeof(ListBox), "SelectedIndex", false));
+Console.WriteLine(observer.GetAffinityForObject(typeof(ListBox), "SelectedItem", false));
+Console.WriteLine(observer.GetAffinityForObject(typeof(TextBox), TextPropertyName, true));
+Console.WriteLine(observer.GetAffinityForObject(typeof(TextBox), "Missing", false));
+Console.WriteLine(observer.GetAffinityForObject(typeof(TodoItem), "Title", false));
+```
+
+```text
+8
+8
+8
+8
+8
+0
+0
+0
+0
+```
+
+The observer raises after each `TextChanged` and carries no value, so the subscriber reads the property. This example subscribes through the observer and reads the text after each change. The change after the subscription ends is not recorded.
+
+```csharp
+WinFormsCreatesObservableForProperty observer = new();
+using WinFormsTodoForm view = new();
+var expression = Expression.Constant(view.FilterTextBox);
+List<string> texts = [];
+
+using (observer.GetNotificationForProperty(view.FilterTextBox, expression, TextPropertyName, false, false).Subscribe(change => texts.Add(((TextBox)change.Sender).Text)))
+{
+    view.FilterTextBox.Text = CarFilter;
+    view.FilterTextBox.Text = CarsFilter;
+}
+
+view.FilterTextBox.Text = CarFilter;
+
+Console.WriteLine(string.Join(", ", texts));
+```
+
+```text
+car, cars
+```
+
+The observer throws `ArgumentException` for a property that has no changed event. The example below asks for a property called `Missing` and records the exception, so a wrong property name fails when you ask for the notification.
+
+```csharp
+WinFormsCreatesObservableForProperty observer = new();
+using WinFormsTodoForm view = new();
+var expression = Expression.Constant(view.FilterTextBox);
+var rejected = false;
+
+try
+{
+    _ = observer.GetNotificationForProperty(view.FilterTextBox, expression, "Missing", false, false);
+}
+catch (ArgumentException)
+{
+    rejected = true;
+}
+
+Console.WriteLine(rejected);
+```
+
+```text
+True
+```
+
+`WhenChanged` on a WinForms control reads the `TextChanged` event at build time, so it needs no registered observer. The example below observes `Text` on a WinForms text box and sets it once. The first value is the empty text the box held when the observation started.
+
+```csharp
+using WinFormsTodoForm view = new();
+List<string> texts = [];
+
+using (view.FilterTextBox.WhenChanged(x => x.Text).Subscribe(texts.Add))
+{
+    view.FilterTextBox.Text = CarFilter;
+}
+
+Console.WriteLine(string.Join(", ", texts));
+```
+
+```text
+, car
+```
+
+### MAUI
+
+A MAUI `BindableObject` reads its dispatcher from `BindableObject.Dispatcher`. MAUI throws `InvalidOperationException` when it finds no dispatcher, as it does in a view's unit test. The MAUI invoker catches that and treats the object as having no owning thread. `CheckAccess` then returns `true` and `Post` runs the callback at once. The example below posts a callback to a control with no dispatcher, as in a unit test. The callback runs before `Post` returns.
+
+```csharp
+DispatcherViewThreadInvoker invoker = new();
+StorageBrowserView view = new();
+List<string> log = [];
+
+invoker.Post(view.UploadProgressBar, static state => ((List<string>)state!).Add(PostedText), log);
+
+Console.WriteLine(string.Join(", ", log));
+```
+
+```text
+posted
+```
+
+The three members work like the other platforms. With no dispatcher, as in a unit test, the calling thread owns every control, so `CheckAccess` is `true` even on a worker thread. The example below calls all three members and prints the answers. The `true` from the worker thread is the difference from WPF and WinForms.
+
+```csharp
+DispatcherViewThreadInvoker invoker = new();
+StorageBrowserView view = new();
+var progressBar = view.UploadProgressBar;
+List<string> log = [];
+object unclaimed = new();
+var accessFromWorker = false;
+
+var worker = new Thread(() => accessFromWorker = invoker.CheckAccess(progressBar));
+worker.Start();
+worker.Join();
+invoker.Post(progressBar, static state => ((List<string>)state!).Add(PostedText), log);
+
+Console.WriteLine(invoker.Claims(progressBar));
+Console.WriteLine(invoker.Claims(unclaimed));
+Console.WriteLine(invoker.CheckAccess(progressBar));
+Console.WriteLine(accessFromWorker);
+Console.WriteLine(string.Join(", ", log));
+```
+
+```text
+True
+False
+True
+True
+posted
+```
+
+You can also call the members through the `IViewThreadInvoker` type. That is how you call any platform's invoker, or one you write. The method below takes the interface, asks whether the invoker claims a progress bar, whether the thread may write and posts a callback. It works the same for every platform.
+
+```csharp
+public static void CallInvokerThroughInterface(IViewThreadInvoker invoker)
+{
+    StorageBrowserView view = new();
+    var progressBar = view.UploadProgressBar;
+    List<string> log = [];
+
+    var claimed = invoker.Claims(progressBar);
+    var mayWrite = invoker.CheckAccess(progressBar);
+    invoker.Post(progressBar, static state => ((List<string>)state!).Add(PostedText), log);
+
+    Console.WriteLine(claimed);
+    Console.WriteLine(mayWrite);
+    Console.WriteLine(string.Join(", ", log));
+}
+```
+
+```text
+True
+True
+posted
+```
+
+A MAUI `BindableObject` raises `PropertyChanged`, so `WhenChanged` works on a MAUI entry with no module. The example below observes the filter entry's `Text` and sets it once. The first value is the empty text the entry held when the observation started.
+
+```csharp
+MauiTodoPage view = new();
+List<string?> texts = [];
+
+using (view.FilterEntry.WhenChanged(x => x.Text).Subscribe(texts.Add))
+{
+    view.FilterEntry.Text = CarFilter;
+}
+
+Console.WriteLine(string.Join(", ", texts));
+```
+
+```text
+, car
+```
+
+### Visibility converters
+
+WPF and MAUI both have a `Visibility` type, and the platform packages ship two converters for it. `BooleanToVisibilityTypeConverter` turns a `bool` into a `Visibility`. `VisibilityToBooleanTypeConverter` turns a `Visibility` back into a `bool`. Both use `BooleanToVisibilityHints` as their conversion hint. `Inverse` flips the result. `UseHidden` gives `Hidden` instead of `Collapsed` for a `false` value. The hints combine with `|`. `None` and any other hint value leave the default behavior. Each converter reports an affinity of 2.
+
+The example below converts a `bool` with each hint, including one that is not a hint, and prints the result. The output shows how `Inverse` and `UseHidden` change the answer and how an unknown hint leaves the default.
+
+```csharp
+BooleanToVisibilityTypeConverter converter = new();
+(bool Value, object? Hint)[] cases =
+[
+    (true, null),
+    (false, null),
+    (false, BooleanToVisibilityHints.None),
+    (true, BooleanToVisibilityHints.Inverse),
+    (false, BooleanToVisibilityHints.Inverse),
+    (false, BooleanToVisibilityHints.UseHidden),
+    (true, BooleanToVisibilityHints.UseHidden),
+    (true, BooleanToVisibilityHints.Inverse | BooleanToVisibilityHints.UseHidden),
+    (false, "not a hint"),
+];
+
+Console.WriteLine(converter.GetAffinityForObjects());
+
+foreach (var (value, hint) in cases)
+{
+    _ = converter.TryConvert(value, hint, out var visibility);
+
+    Console.WriteLine(visibility);
+}
+```
+
+```text
+2
+Visible
+Collapsed
+Collapsed
+Collapsed
+Visible
+Hidden
+Visible
+Hidden
+Collapsed
+```
+
+The reverse converter returns `true` only for `Visible`. The `Inverse` hint flips that. The example below converts each `Visibility` back to a `bool` with different hints, so you can check which values count as visible.
+
+```csharp
+VisibilityToBooleanTypeConverter converter = new();
+(Visibility Value, object? Hint)[] cases =
+[
+    (Visibility.Visible, null),
+    (Visibility.Hidden, null),
+    (Visibility.Collapsed, BooleanToVisibilityHints.None),
+    (Visibility.Visible, BooleanToVisibilityHints.Inverse),
+    (Visibility.Collapsed, BooleanToVisibilityHints.Inverse),
+    (Visibility.Collapsed, "not a hint"),
+];
+
+Console.WriteLine(converter.GetAffinityForObjects());
+
+foreach (var (value, hint) in cases)
+{
+    _ = converter.TryConvert(value, hint, out var isVisible);
+
+    Console.WriteLine(isVisible);
+}
+```
+
+```text
+2
+True
+False
+False
+False
+True
+False
+```
+
+You can bind a tick mark both ways with the two converters. The example below shows the mark when the item is done, and it reopens the item when the mark is hidden. The two converters make that round trip without any code of your own.
+
+```csharp
+TodoItem item = new() { Title = CarRegistrationTitle };
+MauiTodoPage view = new();
+
+using (item.BindTwoWay(view, x => x.IsDone, v => v.DoneMarkVisibility, new BooleanToVisibilityTypeConverter(), new VisibilityToBooleanTypeConverter()))
+{
+    Console.WriteLine(view.DoneMarkVisibility);
+    Console.WriteLine(view.DoneMark.IsVisible);
+
+    item.IsDone = true;
+
+    Console.WriteLine(view.DoneMarkVisibility);
+    Console.WriteLine(view.DoneMark.IsVisible);
+
+    view.DoneMarkVisibility = Visibility.Hidden;
+
+    Console.WriteLine(item.IsDone);
+}
+```
+
+```text
+Collapsed
+False
+Visible
+True
+False
+```
+
+`WpfExamples.cs` has the same converter methods, and its `BindDoneMarkWithBothConverters` binds `DoneMark.Visibility` instead. See [converters](converters.md) for how converters and hints work in a binding.
+
+### Whole screens on each platform
+
+Each platform file in the example project also binds a to-do list and a transfer form to real controls, with the calls from the [bindings](bindings.md) page. Look for `BindTransferFormAsync` and `BindTodoFilterAndCheckBoxAsync` in `AvaloniaExamples.cs`, `WpfExamples.cs`, `WinFormsExamples.cs` and `MauiExamples.cs`. The list and picker screens are `BindItemsListAndSelectionAsync` (Avalonia), `BindItemsListAndPriorityPickerAsync` and `BindPriorityPickerToSelectedIndexAsync` (WinForms) and `BindListViewItemsAndSelectionAsync` (MAUI).
+
+## Run the examples
+
+The example project has two target frameworks. Run it from the folder `src/examples/Documentation/Pages/threading`.
+
+```bash
+dotnet run --framework net10.0
+```
+
+That command runs the Avalonia, MAUI and sequencer examples on any operating system. On Windows, run the WPF examples and then the WinForms examples with these commands.
+
+```bash
+dotnet run --framework net10.0-windows10.0.19041.0
+dotnet run --framework net10.0-windows10.0.19041.0 -- winforms
+```
+
+Related pages:
+
+- [observing](observing.md) covers delivery on the thread that raised a change.
+- [bindings](bindings.md) covers the binding calls.
+- [setup](setup.md) covers the builder.
+- [unsafe](unsafe.md) covers the run-time overloads.
+- [api](api.md) is the full reference.
+
+## API reference
+
+| Member | What it does | Type and values | Notes |
+| --- | --- | --- | --- |
+| [`BindingSchedulers.MainThread`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingSchedulers.cs) | Sets the sequencer that runs a waiting write for an object an invoker claims. | Static property. `ISequencer?`, get and set. | `null` means the invoker's `Post` runs the write. The engine reads it each time it schedules a drain. It never sees a write on the owning thread or a write to an unclaimed object. |
+| [`BindingSchedulers.UseSynchronizationContext`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingSchedulers.cs) | Sets `MainThread` from a synchronization context. | Static method. Takes a `SynchronizationContext?` and returns nothing. | A context becomes a `SynchronizationContextSequencer`. `null` sets `MainThread` to `null`. |
+| [`BindingSchedulers.ObserveOnViewThread`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingSchedulers.cs) | Routes an observable onto the thread that owns a control. | Static method with two overloads. Takes `IObservable<T> source`, `object? target` and, in the second overload, an `IViewThreadInvoker fallback`. Returns `IObservable<T>`. | Returns `source` itself when `target` is `null`. The first overload also returns `source` when no registered invoker claims the target. The second uses `fallback` in that case. A `null` source throws `ArgumentNullException`, and so does a `null` fallback. Hidden from IntelliSense. |
+| [`BindingSchedulers.ObserveOnSequencer`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/BindingSchedulers.cs) | Routes an observable onto a sequencer, so only the newest waiting value is delivered. | Static method. Takes `IObservable<T> source` and `ISequencer scheduler`. Returns `IObservable<T>`. | Every value waits for the sequencer, including the first. Errors and completion follow the waiting value. A `null` source or scheduler throws `ArgumentNullException`. Hidden from IntelliSense. |
+| [`IViewThreadInvoker.Claims`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IViewThreadInvoker.cs) | Says whether the invoker handles an object. | `bool Claims(object target)`. | `true` when the object belongs to the invoker's platform. Answer for one platform's types only. |
+| [`IViewThreadInvoker.CheckAccess`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IViewThreadInvoker.cs) | Says whether the calling thread may write to an object directly. | `bool CheckAccess(object target)`. | `true` on the owning thread, and for an object that has no owning thread. The engine calls it only for an object that `Claims` accepted. |
+| [`IViewThreadInvoker.Post`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IViewThreadInvoker.cs) | Queues a callback on the thread that owns an object. | `void Post(object target, Action<object?> callback, object? state)`. | Hands `state` to `callback` unchanged. Do not run the callback on the calling thread, except for an object that has no owning thread. |
+| [`ViewThreadInvokers.ForTarget`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/ViewThreadInvokers.cs) | Finds the first registered invoker that claims an object. | Static method. Takes `object? target`. Returns `IViewThreadInvoker?`. | Returns `null` when `target` is `null` or nothing claims it. Asks the invokers in registration order. Hidden from IntelliSense. |
+| [`ViewThreadInvokers.Refresh`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/ViewThreadInvokers.cs) | Makes the engine read the registered invokers again. | Static method. Takes nothing and returns nothing. | Call it after you register an invoker when a binding has run. The engine reads the registrations once and keeps them. Hidden from IntelliSense. |
+| [`Wpf.DispatcherViewThreadInvoker`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Wpf.Shared/DispatcherViewThreadInvoker.cs) | Routes writes to a WPF object onto the thread its dispatcher owns. | Sealed class that implements `IViewThreadInvoker`. | Claims `DispatcherObject`. `CheckAccess` asks `DispatcherObject.CheckAccess()`. `Post` queues at normal priority and runs the callback at once for an object with no dispatcher, such as a frozen `Freezable`. Any other type throws `InvalidCastException`. A `null` callback throws `ArgumentNullException`. |
+| [`Wpf.WpfBindingModule`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Wpf.Shared/WpfBindingModule.cs) | Registers the WPF observer and the WPF invoker with a dependency resolver. | Sealed class that implements `IModule`. `Configure(IMutableDependencyResolver resolver)`. | Registers `DependencyObjectObservableForProperty` and `DispatcherViewThreadInvoker`. It registers no Visibility converter. A `null` resolver throws `ArgumentNullException`. |
+| [`WithWpf`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Wpf.Shared/Builder/WpfBindingBuilderExtensions.cs) | Adds the WPF module to the builder. | Extension method on `IReactiveUIBindingBuilder` and on `IAppBuilder`. Returns `IReactiveUIBindingBuilder`. | Returns the builder for chaining. A `null` builder throws `ArgumentNullException`. The `IAppBuilder` overload casts to `IReactiveUIBindingBuilder`. |
+| [`DependencyObjectObservableForProperty.GetAffinityForObject`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Wpf.Shared/DependencyObjectObservableForProperty.cs) | Says how well the WPF observer handles a property. | `int GetAffinityForObject(Type type, string propertyName, bool beforeChanged)`. | Returns 4 for a `DependencyObject` type with a public static `{propertyName}Property` field. Otherwise 0. `beforeChanged` is ignored. |
+| [`DependencyObjectObservableForProperty.GetNotificationForProperty`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Wpf.Shared/DependencyObjectObservableForProperty.cs) | Returns an observable that raises after the dependency property changes. | `IObservable<IObservedChange<object, object?>> GetNotificationForProperty(object sender, Expression expression, string propertyName, bool beforeChanged, bool suppressWarnings)`. | Each notification carries no value. Notifications are always after the change. A `null` sender throws `ArgumentNullException`. A property with no dependency property throws `ArgumentException`. A missing descriptor throws `InvalidOperationException`. |
+| [`Wpf.BooleanToVisibilityHints`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Wpf.Shared/BooleanToVisibilityHints.cs) | Changes how a `bool` maps to a `Visibility`. | Flags enum. `None = 0`, `Inverse = 2`, `UseHidden = 4`. | Pass a value as the conversion hint. Combine values with bitwise or. `Inverse` swaps the mapping. `UseHidden` gives `Hidden` instead of `Collapsed`. |
+| [`Wpf.BooleanToVisibilityTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Wpf.Shared/BooleanToVisibilityTypeConverter.cs) | Converts a `bool` to a `Visibility`. | Sealed class. `BindingTypeConverter<bool, Visibility>`. | `true` gives `Visible`. `false` gives `Collapsed`, or `Hidden` with `UseHidden`. The conversion always succeeds. A hint that is not a `BooleanToVisibilityHints` value counts as `None`. Affinity is 2. |
+| [`Wpf.VisibilityToBooleanTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Wpf.Shared/VisibilityToBooleanTypeConverter.cs) | Converts a `Visibility` to a `bool`. | Sealed class. `BindingTypeConverter<Visibility, bool>`. | `Visible` gives `true`. `Hidden` and `Collapsed` give `false`. `Inverse` flips the result. The conversion always succeeds. Any other hint counts as `None`. Affinity is 2. |
+| [`WinForms.ControlViewThreadInvoker`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.WinForms.Shared/ControlViewThreadInvoker.cs) | Routes writes to a WinForms control onto the thread that created its handle. | Sealed class that implements `IViewThreadInvoker`. | Claims `Control`. `CheckAccess` returns `!Control.InvokeRequired`, so it is `true` while the control has no handle. `Post` uses `BeginInvoke`, or runs the callback at once when no invoke is required. Any other type throws `InvalidCastException`. A `null` callback throws `ArgumentNullException`. |
+| [`WinForms.WinFormsBindingModule`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.WinForms.Shared/WinFormsBindingModule.cs) | Registers the WinForms observer and the control invoker with a dependency resolver. | Sealed class that implements `IModule`. `Configure(IMutableDependencyResolver resolver)`. | Registers `WinFormsCreatesObservableForProperty` and `ControlViewThreadInvoker`. A `null` resolver throws `ArgumentNullException`. |
+| [`WithWinForms`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.WinForms.Shared/Builder/WinFormsBindingBuilderExtensions.cs) | Adds the WinForms module to the builder. | Extension method on `IReactiveUIBindingBuilder` and on `IAppBuilder`. Returns `IReactiveUIBindingBuilder`. | Returns the builder for chaining. A `null` builder throws `ArgumentNullException`. The `IAppBuilder` overload casts to `IReactiveUIBindingBuilder`. |
+| [`WinFormsCreatesObservableForProperty.GetAffinityForObject`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.WinForms.Shared/WinFormsCreatesObservableForProperty.cs) | Says how well the WinForms observer handles a property. | `int GetAffinityForObject(Type type, string propertyName, bool beforeChanged)`. | Returns 8 for a `Component` type with a public instance `{propertyName}Changed` event. Otherwise 0. Returns 0 when `beforeChanged` is `true`. |
+| [`WinFormsCreatesObservableForProperty.GetNotificationForProperty`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.WinForms.Shared/WinFormsCreatesObservableForProperty.cs) | Returns an observable that raises when the control raises its `{propertyName}Changed` event. | `IObservable<IObservedChange<object, object?>> GetNotificationForProperty(object sender, Expression expression, string propertyName, bool beforeChanged, bool suppressWarnings)`. | Each notification carries no value. The handler is added on subscription and removed on disposal. A `null` sender throws `ArgumentNullException`. A type with no such event throws `ArgumentException`. The observer uses reflection, so it carries a trimming warning. |
+| [`Maui.DispatcherViewThreadInvoker`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Maui.Shared/DispatcherViewThreadInvoker.cs) | Routes writes to a MAUI object through the dispatcher it carries. | Sealed class that implements `IViewThreadInvoker`. | Claims `BindableObject`. `CheckAccess` is `false` only when the dispatcher requires a dispatch. `Post` calls `Dispatch`. With no dispatcher, `CheckAccess` is `true` and `Post` runs the callback at once. Any other type throws `InvalidCastException`. A `null` callback throws `ArgumentNullException`. |
+| [`Maui.MauiBindingModule`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Maui.Shared/MauiBindingModule.cs) | Registers the MAUI invoker and the two Visibility converters with a dependency resolver. | Sealed class that implements `IModule`. `Configure(IMutableDependencyResolver resolver)`. | The converters go to the resolver only. `ImportFrom` copies them into a converter service. The WinUI build also registers a dependency-property observer. A `null` resolver throws `ArgumentNullException`. |
+| [`WithMaui`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Maui.Shared/Builder/MauiBindingBuilderExtensions.cs) | Adds the MAUI module to the builder. | Extension method on `IReactiveUIBindingBuilder` and on `IAppBuilder`. Returns `IReactiveUIBindingBuilder`. | Returns the builder for chaining. A `null` builder throws `ArgumentNullException`. The `IAppBuilder` overload casts to `IReactiveUIBindingBuilder`. |
+| [`Maui.BooleanToVisibilityHints`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Maui.Shared/BooleanToVisibilityHints.cs) | Changes how a `bool` maps to a `Visibility`. | Flags enum. `None = 0`, `Inverse = 2`, `UseHidden = 4`. | Same values as the WPF enum. `UseHidden` is ignored on WinUI, which has no `Hidden`. |
+| [`Maui.BooleanToVisibilityTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Maui.Shared/BooleanToVisibilityTypeConverter.cs) | Converts a `bool` to a MAUI `Visibility`. | Sealed class. `BindingTypeConverter<bool, Visibility>`. | Same rules as the WPF converter. The conversion always succeeds. A hint that is not a `BooleanToVisibilityHints` value counts as `None`. Affinity is 2. |
+| [`Maui.VisibilityToBooleanTypeConverter`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Maui.Shared/VisibilityToBooleanTypeConverter.cs) | Converts a MAUI `Visibility` to a `bool`. | Sealed class. `BindingTypeConverter<Visibility, bool>`. | Only `Visible` gives `true`. `Inverse` flips the result. The conversion always succeeds. Any other hint counts as `None`. Affinity is 2. |
diff --git a/docs/documentation/binding/unsafe.md b/docs/documentation/binding/unsafe.md
new file mode 100644
index 00000000..c8844848
--- /dev/null
+++ b/docs/documentation/binding/unsafe.md
@@ -0,0 +1,1473 @@
+---
+Order: 10
+---
+# Unsafe twins and the runtime fallback
+
+[Run the complete page example](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/unsafe/unsafe.csproj).
+
+Most calls in this section are read by the source generator while your project builds. The generator needs the lambda written in the call, such as `x => x.Title`. Sometimes you cannot write it there. The path may sit in a variable, or the name of a column may come from a user, a file or a database. Then the generator has nothing to read, and the plain method throws when it runs.
+
+An **Unsafe twin** is the method for that case. `WhenChangedUnsafe` is the twin of `WhenChanged`, and `BindOneWayUnsafe` is the twin of `BindOneWay`. A twin takes the same kind of arguments, but it reads the property path while the app runs, by reflection. It delivers the same values as the plain method.
+
+Use the plain method whenever you can write the lambda in the call. It is faster and safe to trim. Reach for a twin only when the path is not known until run time.
+
+## Call an Unsafe twin
+
+The examples use a small to-do app. `OriginalTitle` holds the text `Renew car registration`, and the other constants hold sample text of the same kind.
+
+**1. See what a plain call does with a stored path.** The lambda lives in the variable `titleColumn`, so the generator cannot read it at the call. The plain `WhenChanged` is a **stub**, a method that only throws. The message names the twin to use.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+Expression<Func<TodoItem, string>> titleColumn = x => x.Title;
+
+try
+{
+    using var subscription = item.WhenChanged(titleColumn).Subscribe(Console.WriteLine);
+}
+catch (InvalidOperationException ex)
+{
+    Console.WriteLine(ex.Message);
+}
+```
+
+```text
+No generated WhenChanged dispatch matched this call site. Use WhenChangedUnsafe to resolve the expression at run time.
+```
+
+**2. Call the twin before the app is built.** `WhenChangedUnsafe` reads the path at run time. It then asks the registered services how to observe `Title`. The app has registered none, so the call fails. The example prints the first sentence of the message.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+Expression<Func<TodoItem, string>> titleColumn = x => x.Title;
+
+try
+{
+    using var subscription = item.WhenChangedUnsafe(titleColumn).Subscribe(Console.WriteLine);
+}
+catch (InvalidOperationException ex)
+{
+    Console.WriteLine(ex.Message.Split(". ")[0]);
+}
+```
+
+```text
+Could not find a ICreatesObservableForProperty for ReactiveUI.Binding.Documentation.Todo.TodoItem property Title
+```
+
+**3. Build the application once, at startup.** `WithCoreServices` registers the default ways to observe a property and to convert a value. `WithConverter` adds a converter, and `WithCommandBinder` adds a binder that connects a command to a control. Later sections use both. [Setup](setup.md) explains the builder, [Custom converters](custom-converters.md) covers converters, and [Mechanisms](mechanisms.md) covers binders and observation providers.
+
+```csharp
+IReactiveUIBindingBuilder builder = RxBindingBuilder.CreateReactiveUIBindingBuilder();
+
+_ = builder
+    .WithCoreServices()
+    .WithConverter(new TodoItemTitleConverter())
+    .WithCommandBinder(new ButtonClickCommandBinder())
+    .BuildApp();
+```
+
+**4. Call the twin again.** The services are registered, so the twin reads the path and observes the property. It delivers the current title when you subscribe.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+Expression<Func<TodoItem, string>> titleColumn = x => x.Title;
+
+using var subscription = item.WhenChangedUnsafe(titleColumn).Subscribe(Console.WriteLine);
+```
+
+```text
+Renew car registration
+```
+
+## What a twin costs
+
+- **It reads members by reflection.** The twin walks the path at run time, so it is slower than generated code.
+- **It needs registered services.** The twin looks up how to observe each property and how to convert each value. Build the application first, as step 3 shows. The registered observation provider with the highest affinity wins. [Mechanisms](mechanisms.md) explains affinity.
+- **It warns a trimmed publish.** Each twin carries `[RequiresUnreferencedCode]`. That attribute tells the compiler the method reads members by name, so trimming and Native AOT can remove code it needs. The warning appears at your own call site. [Setup](setup.md) covers trimming.
+- **It writes on the owning thread only with a platform module.** A generated binding carries its own fallback for WPF, WinForms and MAUI. A twin uses only the invokers your app registers. [Threading and platforms](threading.md) shows how.
+
+The analyzer marks a call the generator cannot read with the info diagnostic `RXUIBIND001`. [Setup](setup.md) lists the diagnostics.
+
+## Observe properties chosen at run time
+
+Every observation method has a twin. A twin takes an `Expression<Func<TObj, T>>` in place of a lambda the generator reads. Your code can build that expression itself. This example builds `row => row.Title` from a name known only at run time.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+var row = Expression.Parameter(typeof(TodoItem), "row");
+var titleColumn = Expression.Lambda<Func<TodoItem, string>>(Expression.Property(row, nameof(TodoItem.Title)), row);
+List<string> titles = [];
+
+using (item.WhenChangedUnsafe(titleColumn).Subscribe(titles.Add))
+{
+    item.Title = RenamedTitle;
+}
+
+Console.WriteLine(string.Join(", ", titles));
+```
+
+```text
+Renew car registration, Renew car registration online
+```
+
+The twins repeat the same shape for more properties. Each table row below names the twin and the most paths one call takes.
+
+| Twin | Delivers | Most paths in one call |
+| --- | --- | --- |
+| `WhenChangedUnsafe` | Each value after it changes | 16 |
+| `WhenChangingUnsafe` | Each value before it changes | 16 |
+| `WhenAnyValueUnsafe` | Each value after it changes, from any object that notifies | 16 |
+| `WhenAnyUnsafe` | The result of a selector that receives each change | 12 |
+| `WhenAnyObservableUnsafe` | The values of the streams that properties hold | 12 |
+
+`WhenChangedUnsafe` and `WhenChangingUnsafe` take one to sixteen paths. With one path they deliver the value. With two to sixteen they deliver a `PropertyValues` struct, or the result of a selector you add at the end. `WhenAnyValueUnsafe` takes one to sixteen paths, and a selector is allowed from one path up. `WhenAnyUnsafe` takes one to twelve paths and always takes a selector. `WhenAnyObservableUnsafe` takes one to twelve paths to merge streams, and two to twelve with a selector to combine them. [Observing](observing.md) explains `PropertyValues`, selectors and the plain methods.
+
+The [example project](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/tree/main/src/examples/Documentation/Pages/unsafe) has one class for each wide family, such as `UnsafeWhenChangedWideExamples`, `UnsafeWhenAnyValueWideSelectorExamples` and `UnsafeWhenAnyObservableWideExamples`. Each class has one method for every path count.
+
+**Add a selector.** A selector turns the observed values into one result. It receives the values in the order of the paths. This selector joins a title and a done flag into one line, so a screen can show one value instead of two. The output shows a line for the starting state and a line after the flag changes.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+Expression<Func<TodoItem, string>> titleColumn = x => x.Title;
+Expression<Func<TodoItem, bool>> doneColumn = x => x.IsDone;
+List<string> lines = [];
+
+using (item.WhenChangedUnsafe(titleColumn, doneColumn, static (title, done) => done ? $"[x] {title}" : $"[ ] {title}").Subscribe(lines.Add))
+{
+    item.IsDone = true;
+}
+
+Console.WriteLine(string.Join(", ", lines));
+```
+
+```text
+[ ] Renew car registration, [x] Renew car registration
+```
+
+**Observe before a change.** `WhenChangingUnsafe` delivers the value a property held before each change, and nothing when you subscribe. The object must raise `INotifyPropertyChanging`. This example changes the title twice and receives the two earlier titles.
+
+```csharp
+var item = new EditableTodoItem { Title = OriginalTitle };
+Expression<Func<EditableTodoItem, string>> titleColumn = x => x.Title;
+List<string> titles = [];
+
+using (item.WhenChangingUnsafe(titleColumn).Subscribe(titles.Add))
+{
+    item.Title = RenamedTitle;
+    item.Title = FinalTitle;
+}
+
+Console.WriteLine(string.Join(", ", titles));
+```
+
+```text
+Renew car registration, Renew car registration online
+```
+
+**Map a value with a selector.** A selector turns the observed values into one result, and it receives the values in the order of the paths. `WhenAnyValueUnsafe` takes a selector even for one path. This selector maps each title to its length.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+Expression<Func<TodoItem, string>> titleColumn = x => x.Title;
+List<int> lengths = [];
+
+using (item.WhenAnyValueUnsafe(titleColumn, static title => title.Length).Subscribe(lengths.Add))
+{
+    item.Title = RenamedTitle;
+}
+
+Console.WriteLine(string.Join(", ", lengths));
+```
+
+```text
+22, 29
+```
+
+**Read the change itself.** `WhenAnyUnsafe` passes each change to the selector. A change holds the object that changed, in `Sender`, and the new value, in `Value`.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+Expression<Func<TodoItem, string>> titleColumn = x => x.Title;
+List<string> lines = [];
+
+using (item.WhenAnyUnsafe(titleColumn, static change => $"{change.Sender.Id}: {change.Value}").Subscribe(lines.Add))
+{
+    item.Title = RenamedTitle;
+}
+
+Console.WriteLine(string.Join(", ", lines));
+```
+
+```text
+0: Renew car registration, 0: Renew car registration online
+```
+
+**Follow streams that properties hold.** `WhenAnyObservableUnsafe` watches a property that holds an `IObservable<string>` and delivers the values of the stream it holds. When the property gets a new stream, the twin switches to it. With several paths it merges the streams, so each value arrives as its stream delivers it.
+
+```csharp
+TodoAnnouncer announcer = new();
+Expression<Func<TodoAnnouncer, IObservable<string>?>> latestColumn = x => x.Latest;
+Expression<Func<TodoAnnouncer, IObservable<string>?>> urgentColumn = x => x.Urgent;
+List<string> messages = [];
+
+using (announcer.WhenAnyObservableUnsafe(latestColumn, urgentColumn).Subscribe(messages.Add))
+{
+    announcer.Latest = Signal.Return(SyncComplete);
+    announcer.Urgent = Signal.Return(DiskFull);
+}
+
+Console.WriteLine(string.Join(", ", messages));
+```
+
+```text
+Sync complete, Disk full
+```
+
+Add a selector as the last argument to combine the latest value of each stream. The selector runs when every stream has delivered a value, so this example prints one line.
+
+```csharp
+TodoAnnouncer announcer = new();
+Expression<Func<TodoAnnouncer, IObservable<string>?>> latestColumn = x => x.Latest;
+Expression<Func<TodoAnnouncer, IObservable<string>?>> urgentColumn = x => x.Urgent;
+List<string> lines = [];
+
+using (announcer.WhenAnyObservableUnsafe(latestColumn, urgentColumn, static (latest, urgent) => $"{latest} / {urgent}").Subscribe(lines.Add))
+{
+    announcer.Latest = Signal.Return(SyncComplete);
+    announcer.Urgent = Signal.Return(DiskFull);
+}
+
+Console.WriteLine(string.Join(", ", lines));
+```
+
+```text
+Sync complete / Disk full
+```
+
+## Bind with the Unsafe twins
+
+A binding twin takes two expressions, one for each side, and an optional conversion. The twins are `BindOneWayUnsafe`, `BindTwoWayUnsafe`, `OneWayBindUnsafe`, `BindUnsafe`, `BindToUnsafe`, `BindCommandUnsafe`, `InvokeCommandUnsafe` and `BindInteractionUnsafe`. The [API reference](#api-reference) lists the extra arguments of each.
+
+"Written view first" means the call starts from the view, as in `view.BindUnsafe(viewModel, ...)`. [Bindings](bindings.md) explains each plain method.
+
+**Copy a property one way.** The `BindOneWayUnsafe` call takes the source, then the target, then the two expressions. Without a conversion the two properties share one type.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new();
+Expression<Func<TodoListViewModel, string>> source = x => x.FilterText;
+Expression<Func<TodoView, string>> target = v => v.FilterTextBox.Text;
+
+using (viewModel.BindOneWayUnsafe(view, source, target))
+{
+    viewModel.FilterText = FilterQuery;
+}
+
+Console.WriteLine(view.FilterTextBox.Text);
+```
+
+```text
+car
+```
+
+**Convert both ways.** A two-way twin takes one conversion for each direction. A value that a conversion cannot handle is written as the default of the destination type.
+
+```csharp
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+TransferView view = new();
+Expression<Func<TransferViewModel, decimal>> source = x => x.Draft.Amount;
+Expression<Func<TransferView, string>> target = v => v.AmountTextBox.Text;
+
+using (viewModel.BindTwoWayUnsafe(
+    view,
+    source,
+    target,
+    static amount => amount.ToString("F2", CultureInfo.InvariantCulture),
+    static text => decimal.Parse(text, CultureInfo.InvariantCulture)))
+{
+    view.AmountTextBox.Text = AmountText;
+
+    Console.WriteLine(viewModel.Draft.Amount);
+}
+```
+
+```text
+125.50
+```
+
+**Start from the view.** `OneWayBindUnsafe` and `BindUnsafe` are called on the view and take the view model as the first argument. `OneWayBindUnsafe` accepts a selector.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new() { ViewModel = viewModel };
+Expression<Func<TodoListViewModel, int>> source = x => x.RemainingCount;
+Expression<Func<TodoView, string>> target = v => v.RemainingLabel.Text;
+
+using (view.OneWayBindUnsafe(viewModel, source, target, static count => $"{count} left"))
+{
+    Console.WriteLine(view.RemainingLabel.Text);
+}
+```
+
+```text
+3 left
+```
+
+`BindUnsafe` carries the property both ways. Without conversion functions it uses the registered converters. With them it takes the same two functions as `BindTwoWayUnsafe`. The [update stream section](#hold-a-write-until-a-signal-fires) shows it in use.
+
+**Write a stream to a property.** `BindToUnsafe` writes each value a stream delivers. It converts the value with the converter registered for the two types. Pass a hint, a converter or both to change that. A null target writes nothing.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new();
+Expression<Func<TodoListViewModel, TodoItem?>> source = x => x.SelectedItem;
+Expression<Func<TodoView, string?>> target = v => v.SelectedTitleTextBox.Text;
+
+using (viewModel.WhenChangedUnsafe(source).BindToUnsafe(view, target))
+{
+    viewModel.SelectedItem = viewModel.Items[0];
+
+    Console.WriteLine(view.SelectedTitleTextBox.Text);
+}
+```
+
+```text
+Renew car registration
+```
+
+The hint and the converter follow the target expression. The `TodoItemTitleConverter` in the example reads the hint to upper-case the title. [Custom converters](custom-converters.md) shows how to write one. The next call names only the converter. It passes no hint, so the converter leaves the title as it is.
+
+```csharp
+using (viewModel.WhenChangedUnsafe(source).BindToUnsafe(view, target, new TodoItemTitleConverter()))
+{
+    viewModel.SelectedItem = viewModel.Items[0];
+
+    Console.WriteLine(view.SelectedTitleTextBox.Text);
+}
+```
+
+```text
+Renew car registration
+```
+
+The next call names only the hint. The library hands the hint to the converter registered for the two types, which reads it and upper-cases the title. You can change how a registered converter works without naming the converter.
+
+```csharp
+using (viewModel.WhenChangedUnsafe(source).BindToUnsafe(view, target, TodoItemTitleConverter.UpperCaseHint))
+{
+    viewModel.SelectedItem = viewModel.Items[0];
+
+    Console.WriteLine(view.SelectedTitleTextBox.Text);
+}
+```
+
+```text
+RENEW CAR REGISTRATION
+```
+
+The next call names both a hint and a converter. Use it when you want a specific converter to receive a hint in the same call.
+
+```csharp
+using (viewModel.WhenChangedUnsafe(source).BindToUnsafe(view, target, TodoItemTitleConverter.UpperCaseHint, new TodoItemTitleConverter()))
+{
+    viewModel.SelectedItem = viewModel.Items[0];
+
+    Console.WriteLine(view.SelectedTitleTextBox.Text);
+}
+```
+
+```text
+RENEW CAR REGISTRATION
+```
+
+**Run a command for each value.** `InvokeCommandUnsafe` runs the command a property holds for each value of a stream. It skips a value while the property holds no command or the command cannot run. A null target runs nothing. The example waits for the command with a `TaskCompletionSource` that a `PropertyChanged` handler completes. The excerpts leave that wait-handler out.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+Expression<Func<TodoListViewModel, TodoItem?>> source = x => x.SelectedItem;
+Expression<Func<TodoListViewModel, ICommand?>> command = x => x.CompleteCommand;
+
+using (viewModel.WhenChangedUnsafe(source).InvokeCommandUnsafe(viewModel, command))
+{
+    viewModel.SelectedItem = viewModel.Items[0];
+    await completed.Task;
+}
+
+Console.WriteLine(viewModel.RemainingCount);
+```
+
+```text
+2
+```
+
+**Bind a command to a button.** `BindCommandUnsafe` connects the command to the control. It finds the way to do that in the registered command binders, and step 3 registered one for a MAUI `Button`. Without a binder for the control, the command is not connected. Passing `null` as the last argument picks the control's default event. A null view model binds nothing.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new() { ViewModel = viewModel };
+Expression<Func<TodoListViewModel, Command?>> command = x => x.AddCommand;
+Expression<Func<TodoView, Button>> button = v => v.AddButton;
+
+using (view.BindCommandUnsafe(viewModel, command, button, null))
+{
+    viewModel.NewTitle = NewItemTitle;
+    ((IButtonController)view.AddButton).SendClicked();
+    await itemAdded.Task;
+}
+
+Console.WriteLine(viewModel.Items.Count);
+```
+
+```text
+5
+```
+
+Give the command a parameter with an overload that takes a view model property or an `IObservable<T>`. Both go after the control expression and before the event name. The next call passes a stream that delivers one title, and it names the `Clicked` event. The command receives that title as its parameter when the user clicks the button, so the button can send a value the view model did not store.
+
+```csharp
+using (view.BindCommandUnsafe(viewModel, command, button, Signal.Return<string?>(NewItemTitle), nameof(Button.Clicked)))
+{
+    viewModel.NewTitle = NewItemTitle;
+    ((IButtonController)view.AddButton).SendClicked();
+    await itemAdded.Task;
+}
+
+Console.WriteLine(viewModel.Items.Count);
+```
+
+```text
+5
+```
+
+The next call reads the parameter from the view model property `NewTitle`. The command receives whatever the property holds when the button is clicked, so the view model stays in charge of the value.
+
+```csharp
+Expression<Func<TodoListViewModel, string?>> parameter = x => x.NewTitle;
+
+using (view.BindCommandUnsafe(viewModel, command, button, parameter, null))
+{
+    viewModel.NewTitle = NewItemTitle;
+    ((IButtonController)view.AddButton).SendClicked();
+    await itemAdded.Task;
+}
+
+Console.WriteLine(viewModel.Items.Count);
+```
+
+```text
+5
+```
+
+**Register an interaction handler.** `BindInteractionUnsafe` registers a handler on the interaction a property holds. It moves the handler when the property gets another interaction. The handler returns a `Task`, or an `IObservable<T>` in the second overload. A null view model registers nothing.
+
+```csharp
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+TransferView view = new() { ViewModel = viewModel };
+Expression<Func<TransferViewModel, IInteraction<TransferDraft, bool>>> interaction = x => x.ConfirmTransfer;
+
+using (view.BindInteractionUnsafe(
+    viewModel,
+    interaction,
+    static context =>
+    {
+        context.SetOutput(true);
+        return Task.CompletedTask;
+    }))
+{
+    var confirmed = await viewModel.ConfirmTransfer.Handle(viewModel.Draft);
+
+    Console.WriteLine(confirmed);
+}
+```
+
+```text
+True
+```
+
+The observable form of the handler returns a stream instead of a `Task`. This handler sets the output and returns a stream that delivers one value, which suits code that works with streams. The output shows the same answer as the task form.
+
+```csharp
+using (view.BindInteractionUnsafe(
+    viewModel,
+    interaction,
+    static context =>
+    {
+        context.SetOutput(true);
+        return Signal.Return(true);
+    }))
+{
+    var confirmed = await viewModel.ConfirmTransfer.Handle(viewModel.Draft);
+
+    Console.WriteLine(confirmed);
+}
+```
+
+```text
+True
+```
+
+## Write on a sequencer
+
+A **sequencer** decides when queued work runs. [Threading and platforms](threading.md) explains sequencers and the thread that owns a view. Each property-binding twin has an overload that takes an `ISequencer`. The binding delivers each write to the target on that sequencer, and the first write waits too. A newer value replaces a value that waits.
+
+A null sequencer means the binding writes on the thread that owns the target. An immediate sequencer writes inline. The overloads are members of `ReactiveSchedulerExtensions`.
+
+`BindOneWayUnsafe` and `BindTwoWayUnsafe` take a sequencer with no conversion, with conversion `Func` values, or with converters and a hint. `OneWayBindUnsafe` takes one with a selector, or with a converter and a hint. `BindUnsafe` takes one with two conversion `Func` values, or with two converters and a hint.
+
+The sequencer goes after the expressions and any conversion `Func` values. When you pass converters, the order is the converters, the sequencer, then the hint. The example uses a `VirtualClock` from `ReactiveUI.Primitives`. It holds the work until the example calls `Start()`, as a UI thread does between two turns of its message loop.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new();
+VirtualClock sequencer = new();
+Expression<Func<TodoListViewModel, string>> source = x => x.FilterText;
+Expression<Func<TodoView, string>> target = v => v.FilterTextBox.Text;
+
+using (viewModel.BindOneWayUnsafe(view, source, target, sequencer))
+{
+    viewModel.FilterText = FilterQuery;
+
+    Console.WriteLine($"'{view.FilterTextBox.Text}'");
+
+    sequencer.Start();
+
+    Console.WriteLine($"'{view.FilterTextBox.Text}'");
+}
+```
+
+```text
+''
+'car'
+```
+
+A two-way binding waits in only one direction. The write to the target waits on the sequencer, and the write back to the source does not. This means a user's edit reaches the view model at once, while the screen updates when the sequencer runs.
+
+```csharp
+using (viewModel.BindTwoWayUnsafe(view, source, target, sequencer))
+{
+    viewModel.FilterText = FilterQuery;
+
+    Console.WriteLine($"'{view.FilterTextBox.Text}'");
+
+    sequencer.Start();
+
+    Console.WriteLine($"'{view.FilterTextBox.Text}'");
+
+    view.FilterTextBox.Text = SecondFilterQuery;
+
+    Console.WriteLine($"'{viewModel.FilterText}'");
+}
+```
+
+```text
+''
+'car'
+'tax'
+```
+
+A conversion `Func` goes before the sequencer. This call turns an `int` count into text for a label, and the label stays empty until the sequencer starts.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new();
+VirtualClock sequencer = new();
+Expression<Func<TodoListViewModel, int>> source = x => x.RemainingCount;
+Expression<Func<TodoView, string>> target = v => v.RemainingLabel.Text;
+
+using (viewModel.BindOneWayUnsafe(view, source, target, static count => count.ToString(CultureInfo.InvariantCulture), sequencer))
+{
+    Console.WriteLine($"'{view.RemainingLabel.Text}'");
+
+    sequencer.Start();
+
+    Console.WriteLine($"'{view.RemainingLabel.Text}'");
+}
+```
+
+```text
+''
+'3'
+```
+
+Converter objects go before the sequencer and the hint goes after it. This call passes a converter object, the sequencer and a hint that asks for upper case. The output shows the converted title once the sequencer starts.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new();
+VirtualClock sequencer = new();
+Expression<Func<TodoListViewModel, TodoItem?>> source = x => x.SelectedItem;
+Expression<Func<TodoView, string>> target = v => v.SelectedTitleTextBox.Text;
+
+using (viewModel.BindOneWayUnsafe(view, source, target, new TodoItemTitleConverter(), sequencer, TodoItemTitleConverter.UpperCaseHint))
+{
+    viewModel.SelectedItem = viewModel.Items[0];
+    sequencer.Start();
+
+    Console.WriteLine(view.SelectedTitleTextBox.Text);
+}
+```
+
+```text
+RENEW CAR REGISTRATION
+```
+
+A two-way twin takes two converter objects, the sequencer and the hint. This call carries an amount between a `decimal` and text, and it passes `null` for the hint. The output shows the amount as text after the model changes, and then the amount in the model after the view changes.
+
+```csharp
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+TransferView view = new();
+VirtualClock sequencer = new();
+Expression<Func<TransferViewModel, decimal>> source = x => x.Draft.Amount;
+Expression<Func<TransferView, string>> target = v => v.AmountTextBox.Text;
+
+using (viewModel.BindTwoWayUnsafe(view, source, target, new DecimalToStringTypeConverter(), new StringToDecimalTypeConverter(), sequencer, null))
+{
+    sequencer.Start();
+    viewModel.Draft.Amount = AmountValue;
+    sequencer.Start();
+
+    Console.WriteLine(view.AmountTextBox.Text);
+
+    view.AmountTextBox.Text = SecondAmountText;
+
+    Console.WriteLine(viewModel.Draft.Amount);
+}
+```
+
+```text
+125.50
+10.00
+```
+
+`OneWayBindUnsafe` takes a selector before the sequencer. `BindUnsafe` takes two conversion `Func` values, or two converters and a hint. This call starts from the view and turns a count into text with a selector. The label stays empty until the sequencer starts.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new() { ViewModel = viewModel };
+VirtualClock sequencer = new();
+Expression<Func<TodoListViewModel, int>> source = x => x.RemainingCount;
+Expression<Func<TodoView, string>> target = v => v.RemainingLabel.Text;
+
+using (view.OneWayBindUnsafe(viewModel, source, target, static count => $"{count} left", sequencer))
+{
+    Console.WriteLine($"'{view.RemainingLabel.Text}'");
+
+    sequencer.Start();
+
+    Console.WriteLine($"'{view.RemainingLabel.Text}'");
+}
+```
+
+```text
+''
+'3 left'
+```
+
+The next `BindUnsafe` call starts from the view and carries an amount both ways through two converter objects. It passes `null` for the hint. The output shows the amount as text once the sequencer has run.
+
+```csharp
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+TransferView view = new() { ViewModel = viewModel };
+VirtualClock sequencer = new();
+Expression<Func<TransferViewModel, decimal>> source = x => x.Draft.Amount;
+Expression<Func<TransferView, string>> target = v => v.AmountTextBox.Text;
+
+using (view.BindUnsafe(viewModel, source, target, new DecimalToStringTypeConverter(), new StringToDecimalTypeConverter(), sequencer, null))
+{
+    sequencer.Start();
+    viewModel.Draft.Amount = AmountValue;
+    sequencer.Start();
+
+    Console.WriteLine(view.AmountTextBox.Text);
+}
+```
+
+```text
+125.50
+```
+
+## Hold a write until a signal fires
+
+A two-way binding copies every edit at once. Sometimes one side should wait. A filter box may search only when the user commits the text. A screen may redraw only when a refresh tick arrives. `BindUnsafe` takes an **update stream** for this. Each value the stream delivers tells the binding to copy one direction. The values themselves are ignored.
+
+`TriggerUpdate` names the direction the stream drives.
+
+| `TriggerUpdate` | What the stream drives | What is not held back |
+| --- | --- | --- |
+| `ViewToViewModel` | Writes to the view model | View model changes reach the view at once. |
+| `ViewModelToView` | Writes to the view | View edits reach the view model at once. |
+
+`ViewToViewModel` is the default, so the first example names no direction. The binding holds the view edit until the `commit` stream fires. It then copies the text to the view model.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new() { ViewModel = viewModel };
+Signal<EventArgs> commit = new();
+
+using (view.BindUnsafe(viewModel, x => x.FilterText, v => v.FilterTextBox.Text, commit))
+{
+    view.FilterTextBox.Text = FilterQuery;
+
+    Console.WriteLine($"'{viewModel.FilterText}'");
+
+    commit.OnNext(EventArgs.Empty);
+
+    Console.WriteLine($"'{viewModel.FilterText}'");
+
+    viewModel.FilterText = SecondFilterQuery;
+
+    Console.WriteLine($"'{view.FilterTextBox.Text}'");
+}
+```
+
+```text
+''
+'car'
+'tax'
+```
+
+Pass `TriggerUpdate.ViewModelToView` after the stream to hold view model changes instead. The view model change then reaches the view when the `refresh` stream fires, and a view edit reaches the view model at once.
+
+The binding reads the property when the stream fires, not when the property changes. Several changes between two signals become one write with the latest value. This example changes the text twice and counts one write.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new() { ViewModel = viewModel };
+Signal<EventArgs> refresh = new();
+var writes = 0;
+
+using (view.BindUnsafe(viewModel, x => x.FilterText, v => v.FilterTextBox.Text, refresh, TriggerUpdate.ViewModelToView))
+{
+    view.FilterTextBox.PropertyChanged += (_, e) => writes += e.PropertyName == nameof(view.FilterTextBox.Text) ? 1 : 0;
+
+    viewModel.FilterText = FilterQuery;
+    viewModel.FilterText = SecondFilterQuery;
+    refresh.OnNext(EventArgs.Empty);
+
+    Console.WriteLine(view.FilterTextBox.Text);
+    Console.WriteLine(writes);
+}
+```
+
+```text
+tax
+1
+```
+
+When the binding starts, it writes the view model value to the view in both directions, so a view never starts empty while it waits for the first signal. A null stream turns the option off. The binding then observes both properties and copies each change at once, as `BindUnsafe` does without a stream.
+
+A converted binding takes the two conversion `Func` values before the stream. This example refreshes an amount that the view shows as text.
+
+```csharp
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+TransferView view = new() { ViewModel = viewModel };
+Signal<EventArgs> refresh = new();
+
+using (view.BindUnsafe(
+    viewModel,
+    x => x.Draft.Amount,
+    v => v.AmountTextBox.Text,
+    static amount => amount.ToString("F2", CultureInfo.InvariantCulture),
+    static text => decimal.Parse(text, CultureInfo.InvariantCulture),
+    refresh,
+    TriggerUpdate.ViewModelToView))
+{
+    viewModel.Draft.Amount = AmountValue;
+
+    Console.WriteLine(view.AmountTextBox.Text);
+
+    refresh.OnNext(EventArgs.Empty);
+
+    Console.WriteLine(view.AmountTextBox.Text);
+}
+```
+
+```text
+0.00
+125.50
+```
+
+## Call the runtime fallback types
+
+The twins are thin. Each one passes its expressions to a static class in `ReactiveUI.Binding.Fallback`, and generated code calls the same classes. You can call them yourself. All but `RuntimeBindingConverter` are hidden from IntelliSense, because generated code is their main caller. The observation, binding, command and interaction methods carry `[RequiresUnreferencedCode]`.
+
+Most binding members end with a `bindingExpression` string. It names the bound expression in the log entry that a failed write produces. The examples pass constants such as `FilterExpression`, which holds `x => x.FilterText`.
+
+### Observe with RuntimeObservationFallback
+
+`RuntimeObservationFallback` has `WhenChanged`, `WhenChanging` and `WhenAnyValue`. Each takes one, two or three property expressions. The after-change methods deliver the current value when you subscribe. When a link along the path is null, they deliver nothing until the path resolves. The methods for two or three paths deliver once every path has a value.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+List<string> titles = [];
+
+using (RuntimeObservationFallback.WhenChanged(item, x => x.Title).Subscribe(titles.Add))
+{
+    item.Title = RenamedTitle;
+}
+
+Console.WriteLine(string.Join(", ", titles));
+```
+
+```text
+Renew car registration, Renew car registration online
+```
+
+Two paths deliver a `PropertyValues` struct with both values on every change. This call watches a title and a done flag, and each change prints both. You get a consistent pair without reading the second property yourself.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+
+using (RuntimeObservationFallback.WhenChanged(item, x => x.Title, x => x.IsDone).Subscribe(static values => Console.WriteLine($"{values.Property1} {values.Property2}")))
+{
+    item.IsDone = true;
+}
+```
+
+```text
+Renew car registration False
+Renew car registration True
+```
+
+`WhenChanged` accepts up to three paths. Three paths follow the same pattern and deliver all three values on each change.
+
+`WhenChanging` delivers the value before each change. The object must raise `INotifyPropertyChanging`, and the call delivers nothing when you subscribe. This call changes the title once and collects the value the title held before that change. Use it when you need the old value, for example to undo an edit.
+
+```csharp
+var item = new EditableTodoItem { Title = OriginalTitle };
+List<string> titles = [];
+
+using (RuntimeObservationFallback.WhenChanging(item, x => x.Title).Subscribe(titles.Add))
+{
+    item.Title = RenamedTitle;
+}
+
+Console.WriteLine(string.Join(", ", titles));
+```
+
+```text
+Renew car registration
+```
+
+It accepts up to three paths. With two paths, each change delivers both values as they stood before the change. This call changes the notes, and the output shows the old notes with the title.
+
+```csharp
+var item = new EditableTodoItem { Title = OriginalTitle, Notes = OriginalNotes };
+
+using (RuntimeObservationFallback.WhenChanging(item, x => x.Title, x => x.Notes).Subscribe(static values => Console.WriteLine($"{values.Property1} {values.Property2}")))
+{
+    item.Notes = ReplacementNotes;
+}
+```
+
+```text
+Renew car registration Bring the insurance certificate.
+```
+
+Three paths follow the same pattern.
+
+`WhenAnyValue` delivers the value after each change, with one, two or three paths. This first call watches one property and collects the title when you subscribe and again after the change.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+List<string> titles = [];
+
+using (RuntimeObservationFallback.WhenAnyValue(item, x => x.Title).Subscribe(titles.Add))
+{
+    item.Title = RenamedTitle;
+}
+
+Console.WriteLine(string.Join(", ", titles));
+```
+
+```text
+Renew car registration, Renew car registration online
+```
+
+With two paths, `WhenAnyValue` delivers a pair after each change. This call raises the priority, and the output shows the pair before and after, so a screen can redraw with both values at once.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+
+using (RuntimeObservationFallback.WhenAnyValue(item, x => x.Title, x => x.Priority).Subscribe(static values => Console.WriteLine($"{values.Property1} {values.Property2}")))
+{
+    item.Priority = TodoPriority.High;
+}
+```
+
+```text
+Renew car registration Normal
+Renew car registration High
+```
+
+Three paths follow the same pattern and deliver a struct of three values.
+
+### Bind with RuntimeBindingFallback
+
+`RuntimeBindingFallback` holds the binding methods. A method ends with a sequencer, which may be `null`, and the `bindingExpression`. A conversion, when the method takes one, comes before the sequencer.
+
+The methods are `BindOneWay`, `BindTwoWay`, `OneWayBind`, `Bind` and `BindTo`. The [API reference](#api-reference) lists the overloads of each.
+
+`BindOneWay` and `BindTwoWay` take the source first and the target second. `OneWayBind` and `Bind` take the view first. The `null` and the string at the end of each call are the sequencer and the expression text. This call carries a filter text from a view model to a text box. It shows the simplest binding call, and the output shows the text box holding the new filter.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new();
+
+using (RuntimeBindingFallback.BindOneWay(viewModel, view, x => x.FilterText, v => v.FilterTextBox.Text, null, FilterExpression))
+{
+    viewModel.FilterText = FilterQuery;
+}
+
+Console.WriteLine(view.FilterTextBox.Text);
+```
+
+```text
+car
+```
+
+`OneWayBind` starts from the view and takes a conversion `Func` when the two properties differ in type. This call turns a count into the text of a label, and the output shows the label holding the text as soon as the binding starts.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new() { ViewModel = viewModel };
+
+using (RuntimeBindingFallback.OneWayBind(
+    view,
+    viewModel,
+    x => x.RemainingCount,
+    v => v.RemainingLabel.Text,
+    static count => $"{count} left",
+    null,
+    RemainingCountExpression))
+{
+    Console.WriteLine(view.RemainingLabel.Text);
+}
+```
+
+```text
+3 left
+```
+
+`Bind` carries a property both ways and starts from the view. This call types text into a text box and reads the text back from the view model, so the output shows the edit reaching the view model.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new() { ViewModel = viewModel };
+
+using (RuntimeBindingFallback.Bind(view, viewModel, x => x.FilterText, v => v.FilterTextBox.Text, null, FilterExpression))
+{
+    view.FilterTextBox.Text = FilterQuery;
+
+    Console.WriteLine(viewModel.FilterText);
+}
+```
+
+```text
+car
+```
+
+A two-way method takes a `TwoWayConverterPair` where a one-way method takes a conversion `Func`. The example's `CreateAmountConverters()` builds a pair for an amount and its text. This call types an amount into a text box, and the output shows the view model holding the parsed `decimal`.
+
+```csharp
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+TransferView view = new();
+
+using (RuntimeBindingFallback.BindTwoWay(viewModel, view, x => x.Draft.Amount, v => v.AmountTextBox.Text, CreateAmountConverters(), null, AmountExpression))
+{
+    view.AmountTextBox.Text = AmountText;
+
+    Console.WriteLine(viewModel.Draft.Amount);
+}
+```
+
+```text
+125.50
+```
+
+The `Bind` overloads that take an update stream end with the stream and a `TriggerUpdate` value, in place of the sequencer and the expression text. This call holds the view edit until `commit` fires. The output shows the view model empty after the edit and holding the text after the signal.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+TodoView view = new() { ViewModel = viewModel };
+Signal<EventArgs> commit = new();
+
+using (RuntimeBindingFallback.Bind(view, viewModel, x => x.FilterText, v => v.FilterTextBox.Text, commit, TriggerUpdate.ViewToViewModel))
+{
+    view.FilterTextBox.Text = FilterQuery;
+
+    Console.WriteLine($"'{viewModel.FilterText}'");
+
+    commit.OnNext(EventArgs.Empty);
+
+    Console.WriteLine($"'{viewModel.FilterText}'");
+}
+```
+
+```text
+''
+'car'
+```
+
+`BindTo` takes the stream first. A null target drops the values, because a view has no property to write before it exists. The three `null` arguments are the hint, the converter and the sequencer. This call passes a null target and selects an item. The output shows the selection changing and the call not failing, because a view often does not exist yet when a stream starts.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+var selected = RuntimeObservationFallback.WhenChanged(viewModel, x => x.SelectedItem);
+TodoView? missing = default;
+
+using (RuntimeBindingFallback.BindTo(selected, missing, v => v.SelectedTitleTextBox.Text, null, null, null, SelectedTitleExpression))
+{
+    viewModel.SelectedItem = viewModel.Items[0];
+
+    Console.WriteLine(ReferenceEquals(viewModel.Items[0], viewModel.SelectedItem));
+}
+```
+
+```text
+True
+```
+
+### Convert with RuntimeBindingConverter and TwoWayConverters
+
+`RuntimeBindingConverter.TryConvert` converts a value from one type to another. It returns `false` and leaves the default in `result` when no converter can do it. A converter you pass wins over the registered ones. Otherwise it uses the converter registered for the two types. The hint goes to the converter, which decides what it means. This call converts a to-do item to text with a converter you name and a hint that asks for upper case. Use it to test a converter without a binding.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+
+var converted = RuntimeBindingConverter.TryConvert<TodoItem, string>(item, TodoItemTitleConverter.UpperCaseHint, new TodoItemTitleConverter(), out var text);
+
+Console.WriteLine(converted);
+Console.WriteLine(text);
+```
+
+```text
+True
+RENEW CAR REGISTRATION
+```
+
+Pass `null` for the hint and the converter to use the registered converter. The methods `ConvertWithRegisteredConverter` and `ConvertWithConversionHint` in the [example project](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/unsafe/FallbackRuntimeExamples.cs) show both. The next call asks for a conversion that no converter provides, from `TodoItem` to `int`. It returns `false` and the default of the result type, so check the result before you use the value.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+
+var converted = RuntimeBindingConverter.TryConvert<TodoItem, int>(item, null, null, out var number);
+
+Console.WriteLine(converted);
+Console.WriteLine(number);
+```
+
+```text
+False
+0
+```
+
+`TwoWayConverters.Create` pairs a forward and a reverse conversion into a `TwoWayConverterPair` and infers both types. This call builds a pair between a `decimal` and text and runs each direction. The output shows both conversions giving the same text.
+
+```csharp
+var pair = TwoWayConverters.Create<decimal, string>(
+    static amount => amount.ToString("F2", CultureInfo.InvariantCulture),
+    static text => decimal.Parse(text, CultureInfo.InvariantCulture));
+
+Console.WriteLine(pair.Forward(AmountValue));
+Console.WriteLine(pair.Reverse(AmountText));
+```
+
+```text
+125.50
+125.50
+```
+
+`TwoWayConverterPair<TSourceProp, TTargetProp>` is a record, so two pairs built from the same two functions are equal. The `with` expression replaces one function. This call compares two equal pairs, and then a pair with a changed forward function. The output shows the first comparison true, the second false and the new function rounding to a whole number.
+
+```csharp
+Func<decimal, string> forward = static amount => amount.ToString("F2", CultureInfo.InvariantCulture);
+Func<string, decimal> reverse = static text => decimal.Parse(text, CultureInfo.InvariantCulture);
+TwoWayConverterPair<decimal, string> pair = new(forward, reverse);
+TwoWayConverterPair<decimal, string> same = new(forward, reverse);
+var swapped = pair with { Forward = static amount => amount.ToString("F0", CultureInfo.InvariantCulture) };
+
+Console.WriteLine(pair.Equals(same));
+Console.WriteLine(pair.Equals(swapped));
+Console.WriteLine(swapped.Forward(AmountValue));
+```
+
+```text
+True
+False
+126
+```
+
+### Commands and interactions
+
+`RuntimeCommandBindingFallback.BindCommand` connects a command to a control, `RuntimeCommandFallback.InvokeCommand` runs a command for each value of a stream, and `RuntimeInteractionFallback.BindInteraction` registers an interaction handler. `BindCommand` takes a stream of parameters and an optional event name. A null view model is the ordinary state before a view model is assigned, and the binding then does nothing. This call passes a null view model. The output shows the button has no command, which means the call is safe to make early.
+
+```csharp
+TodoView view = new();
+TodoListViewModel? missing = default;
+
+using (RuntimeCommandBindingFallback.BindCommand(view, missing, x => x.AddCommand, v => v.AddButton, Signal.Never<object?>(), null, AddCommandExpression))
+{
+    Console.WriteLine(view.AddButton.Command is null);
+}
+```
+
+```text
+True
+```
+
+`InvokeCommand` takes the stream, the target and the command property. As before, the excerpt leaves out the `TaskCompletionSource` wait-handler. This call runs the complete command for each item that is selected. The output shows the remaining count falling to two.
+
+```csharp
+var viewModel = await LoadTodoAsync();
+var selected = RuntimeObservationFallback.WhenAnyValue(viewModel, x => x.SelectedItem);
+
+using (RuntimeCommandFallback.InvokeCommand(selected, viewModel, x => x.CompleteCommand))
+{
+    viewModel.SelectedItem = viewModel.Items[0];
+    await completed.Task;
+}
+
+Console.WriteLine(viewModel.RemainingCount);
+```
+
+```text
+2
+```
+
+`BindInteraction` takes the view model, the interaction property, a callback that registers the handler on the interaction, and the expression text. This call registers a handler that confirms the transfer. The output shows the view model receiving the answer `True`, so the view model can ask the user a question without knowing about the screen.
+
+```csharp
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+
+using (RuntimeInteractionFallback.BindInteraction(
+    viewModel,
+    x => x.ConfirmTransfer,
+    static interaction => interaction.RegisterHandler(static context =>
+    {
+        context.SetOutput(true);
+        return Task.CompletedTask;
+    }),
+    "x => x.ConfirmTransfer"))
+{
+    var confirmed = await viewModel.ConfirmTransfer.Handle(viewModel.Draft);
+
+    Console.WriteLine(confirmed);
+}
+```
+
+```text
+True
+```
+
+## Read and write a path
+
+The twins walk a property path with two static classes in `ReactiveUI.Binding.Expressions`: `Reflection` and `ExpressionMixins`. You can call them to read a path yourself. A path such as `x.Draft.Amount` has two **links**, `Draft` and `Amount`, and each link is one member access or one indexer.
+
+The extension members `GetExpressionChain`, `GetMemberInfo`, `GetParent` and `GetArgumentsArray` are on `ExpressionMixins`. The rest are on `Reflection`. The [API reference](#api-reference) lists each one. This call names the path of a lambda, and the output shows the property names joined by dots. That text is what the twins use to describe a binding in a log entry.
+
+```csharp
+Expression<Func<TransferViewModel, decimal>> path = x => x.Draft.Amount;
+
+Console.WriteLine(Reflection.ExpressionToPropertyNames(path.Body));
+```
+
+```text
+Draft.Amount
+```
+
+`GetExpressionChain` returns one expression for each link, from the root outwards. This call splits `x.Draft.Amount` into its two links and prints their names, so you can work with each link on its own.
+
+```csharp
+Expression<Func<TransferViewModel, decimal>> path = x => x.Draft.Amount;
+
+var chain = new List<Expression>(path.Body.GetExpressionChain());
+
+Console.WriteLine(chain.Count);
+Console.WriteLine(((MemberExpression)chain[0]).Member.Name);
+Console.WriteLine(((MemberExpression)chain[1]).Member.Name);
+```
+
+```text
+2
+Draft
+Amount
+```
+
+The compiler adds a conversion when it boxes a value. `GetMemberInfo` looks through that conversion to the member. This call reads a lambda that returns an `int` as an `object`, and the output shows the conversion and then the property name `Id`.
+
+```csharp
+Expression<Func<TodoItem, object>> path = x => x.Id;
+
+Console.WriteLine(path.Body.NodeType);
+Console.WriteLine(path.Body.GetMemberInfo()!.Name);
+```
+
+```text
+Convert
+Id
+```
+
+`GetParent` returns the expression a link is read from. This call asks for the parent of the last link in `x.Draft.Amount`, and the output shows it is `Draft`. Use it to walk a path backwards.
+
+```csharp
+Expression<Func<TransferViewModel, decimal>> path = x => x.Draft.Amount;
+
+var parent = (MemberExpression)path.Body.GetParent()!;
+
+Console.WriteLine(parent.Member.Name);
+```
+
+```text
+Draft
+```
+
+`GetArgumentsArray` returns the arguments of an indexer link, and `null` for a plain member. The arguments must be constants. The compiler writes an indexer as a method call, so `Rewrite` turns it into an indexer link first. This call reads the argument of `x.Tags[0]`, and then shows that a plain member has no arguments. The output shows an index link with one argument, `0`.
+
+```csharp
+Expression<Func<TodoItem, string>> path = x => x.Tags[0];
+
+var indexer = Reflection.Rewrite(path.Body);
+var arguments = indexer.GetArgumentsArray();
+
+Console.WriteLine(indexer.NodeType);
+Console.WriteLine(arguments!.Length);
+Console.WriteLine((int)arguments[0]!);
+
+Expression<Func<TodoItem, string>> member = x => x.Title;
+
+Console.WriteLine(member.Body.GetArgumentsArray() is null);
+```
+
+```text
+Index
+1
+0
+True
+```
+
+`Rewrite` also removes a conversion, so the boxed `x => x.Id` from above becomes a plain member access.
+
+**Read and write one member.** A fetcher reads a member and a setter writes it. Each has two forms. The `ForProperty` form returns `null` for a member that is not a property or a field. The `OrThrow` form throws `ArgumentException`. The fetcher for a field throws `InvalidOperationException` when the field holds null. The fetcher takes the object and the indexer arguments, and the setter takes the object, the value and the indexer arguments. The arguments are `null` for a property.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+var title = typeof(TodoItem).GetProperty(TitleName);
+
+var fetcher = Reflection.GetValueFetcherForProperty(title);
+
+Console.WriteLine((string)fetcher!(item, null)!);
+Console.WriteLine(Reflection.GetValueFetcherForProperty(typeof(TodoItem).GetMethod(nameof(TodoItem.Clone))) is null);
+```
+
+```text
+Renew car registration
+True
+```
+
+The `OrThrow` fetcher fails loudly for a member it cannot read, which is better when a missing property is a mistake. The `Throws` method in the example reports whether an action throws the exception you name. This call reads the title, and then asks for a fetcher for a method, which throws.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+var fetcher = Reflection.GetValueFetcherOrThrow(typeof(TodoItem).GetProperty(TitleName));
+
+Console.WriteLine((string)fetcher(item, null)!);
+Console.WriteLine(Throws<ArgumentException>(static () => Reflection.GetValueFetcherOrThrow(typeof(TodoItem).GetMethod(nameof(TodoItem.Clone)))));
+```
+
+```text
+Renew car registration
+True
+```
+
+A setter writes the value it receives. This call builds a setter for the title and writes a new title with it. The output shows the new title, and then shows that the `ForProperty` setter returns `null` for a method.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+var setter = Reflection.GetValueSetterForProperty(typeof(TodoItem).GetProperty(TitleName));
+
+setter!(item, RenamedTitle, null);
+
+Console.WriteLine(item.Title);
+Console.WriteLine(Reflection.GetValueSetterForProperty(typeof(TodoItem).GetMethod(nameof(TodoItem.Clone))) is null);
+```
+
+```text
+Renew car registration online
+True
+```
+
+The `OrThrow` setter writes the title in the same way and throws for a method. Choose it when you want a mistake to stop the program instead of doing nothing.
+
+```csharp
+var item = new TodoItem { Title = OriginalTitle };
+var setter = Reflection.GetValueSetterOrThrow(typeof(TodoItem).GetProperty(TitleName));
+
+setter(item, RenamedTitle, null);
+
+Console.WriteLine(item.Title);
+Console.WriteLine(Throws<ArgumentException>(static () => Reflection.GetValueSetterOrThrow(typeof(TodoItem).GetMethod(nameof(TodoItem.Clone)))));
+```
+
+```text
+Renew car registration online
+True
+```
+
+**Read and write a whole path.** The chain methods take the links from `GetExpressionChain`. The example builds them with a small helper named `CreateChain`. `TryGetValueForPropertyChain` returns `true` and the value when it reaches the end of the path. This call reads the amount of a draft transfer, and the output shows that it found the amount.
+
+```csharp
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+viewModel.Draft.Amount = AmountValue;
+var chain = CreateChain<TransferViewModel, decimal>(static x => x.Draft.Amount);
+
+var found = Reflection.TryGetValueForPropertyChain<decimal>(out var amount, viewModel, chain);
+
+Console.WriteLine(found);
+Console.WriteLine(amount);
+```
+
+```text
+True
+125.50
+```
+
+It returns `false` and a default value when a link along the path is null. This path ends at `SelectedItem!.Title`, and no item is selected. The output shows `False` and a null title, so you can tell a missing value from an empty one.
+
+```csharp
+var viewModel = new TodoListViewModel(InMemoryTodoStore.CreateSeeded());
+var chain = CreateChain<TodoListViewModel, string>(static x => x.SelectedItem!.Title);
+
+var found = Reflection.TryGetValueForPropertyChain<string>(out var title, viewModel, chain);
+
+Console.WriteLine(found);
+Console.WriteLine(title is null);
+```
+
+```text
+False
+True
+```
+
+`TryGetAllValuesForPropertyChain` returns one entry for each link. Each entry holds the object the link was read from, in `Sender`, and the value. The entries from the first null link on are `null`. This call reads both links of the draft amount path, and the output checks each entry against the objects it should hold. It shows the path was read one link at a time.
+
+```csharp
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+viewModel.Draft.Amount = AmountValue;
+var chain = CreateChain<TransferViewModel, decimal>(static x => x.Draft.Amount);
+
+var found = Reflection.TryGetAllValuesForPropertyChain(out var changes, viewModel, chain);
+
+Console.WriteLine(found);
+Console.WriteLine(changes.Length);
+Console.WriteLine(ReferenceEquals(viewModel, changes[0].Sender));
+Console.WriteLine(ReferenceEquals(viewModel.Draft, changes[0].Value));
+Console.WriteLine(ReferenceEquals(viewModel.Draft, changes[1].Sender));
+Console.WriteLine((decimal)changes[1].Value!);
+```
+
+```text
+True
+2
+True
+True
+True
+125.50
+```
+
+`TrySetValueToPropertyChain` writes the value at the end of a path. It returns `false` when the object that owns the last property is null. It throws `ArgumentNullException` when a link earlier in the path is null. This call writes an amount through the draft, and the output shows the write succeeded and the draft holds the amount.
+
+```csharp
+TransferViewModel viewModel = new(new InMemoryBankingBackend());
+var chain = CreateChain<TransferViewModel, decimal>(static x => x.Draft.Amount);
+
+var written = Reflection.TrySetValueToPropertyChain(viewModel, chain, AmountValue);
+
+Console.WriteLine(written);
+Console.WriteLine(viewModel.Draft.Amount);
+```
+
+```text
+True
+125.50
+```
+
+By default the method throws when a link is not a property or a field. A fourth argument of `false` skips such a link instead and returns `false` when the last member cannot be written. This call sets the title of an item with the fourth argument `false`, and the output shows the title changed.
+
+```csharp
+var item = new TodoItem { Tags = [FirstTag] };
+var chain = CreateChain<TodoItem, string>(static x => x.Title);
+
+var written = Reflection.TrySetValueToPropertyChain(item, chain, RenamedTitle, false);
+
+Console.WriteLine(written);
+Console.WriteLine(item.Title);
+```
+
+```text
+True
+Renew car registration online
+```
+
+## Where to go next
+
+- [Observing](observing.md) covers the plain observation methods that these twins mirror.
+- [Bindings](bindings.md) covers the plain binding methods, commands and interactions.
+- [Mechanisms](mechanisms.md) covers the providers and binders that the fallback looks up.
+- [Threading and platforms](threading.md) covers the owning thread, sequencers and the platform modules.
+- [Setup](setup.md) covers the builder, trimming and the analyzer diagnostics.
+- [API reference](api.md) lists every twin and fallback member.
+
+## API reference
+
+The first column links to the source file. A twin that repeats for each number of paths has one row, and its type column gives the most paths one call takes and the range. Most members that read a path by reflection carry `[RequiresUnreferencedCode]`.
+
+| Member | What it does | Type and values | Notes |
+| --- | --- | --- | --- |
+| [`WhenChangedUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenChanged.WideArity.Unsafe.cs) | Observes properties by reflection and delivers each value after it changes. | Extension on a class in `ReactiveUI.Binding`. Takes one to 16 paths, up to `PropertyValues<T1, ..., T16>`. One path returns `IObservable<T1>`. Two or more return `IObservable<PropertyValues<...>>`, or `IObservable<TReturn>` with a selector (two to 16 paths). | Delivers the current value when you subscribe. A null object or path throws `ArgumentNullException`. The selector forms are in [the selector file](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenChanged.Selectors.WideArity.Unsafe.cs). |
+| [`WhenChangingUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenChanging.WideArity.Unsafe.cs) | Observes properties by reflection and delivers each value as it stood before a change. | Extension on a class. Takes one to 16 paths, up to `PropertyValues<T1, ..., T16>`. The return types match `WhenChangedUnsafe`, with a selector from two to 16 paths. | The object must raise `INotifyPropertyChanging`. A null object or path throws `ArgumentNullException`. |
+| [`WhenAnyValueUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenAnyValue.WideArity.Unsafe.cs) | Observes properties by reflection and delivers each value after it changes. | Extension on a class. Takes one to 16 paths, up to `PropertyValues<T1, ..., T16>`. With a selector it returns `IObservable<TRet>`, from one to 16 paths. | Delivers the current value when you subscribe. A null sender or path throws `ArgumentNullException`. |
+| [`WhenAnyUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenAny.WideArity.Unsafe.cs) | Observes properties by reflection and passes each change to a selector. | Extension on a class. Takes one to 12 paths and always a `Func` selector over `IObservedChange<TSender, T>` values. Returns `IObservable<TRet>`. | Delivers when you subscribe and after any change. A null sender or path throws `ArgumentNullException`. |
+| [`WhenAnyObservableUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.WhenAnyObservable.WideArity.Unsafe.cs) | Follows the streams that properties hold and delivers their values. | Extension on a class. Takes one to 12 paths to `IObservable<TRet>?` properties and returns `IObservable<TRet>`. Two to 12 paths and a selector combine the latest value of each stream. | One path switches to the new stream when the property changes. Several paths merge their streams. A null stream delivers nothing. |
+| [`BindOneWayUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.Binding.Unsafe.cs) | Copies a source property to a target property. | Returns `IDisposable`. Takes the same type, or a conversion `Func`. | Writes on the target's owning thread when a registered invoker claims it. A null conversion throws `ArgumentNullException`. |
+| [`BindTwoWayUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.Binding.Unsafe.cs) | Carries a property both ways between two objects. | Returns `IDisposable`. Takes the same type, or two conversion `Func` values. | Seeds the target from the source. Each side writes on its owning thread when a registered invoker claims it. |
+| [`OneWayBindUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.Binding.Unsafe.cs) | Copies a view model property to a view property, called on the view. | Returns `IReactiveBinding<TView, TVProp>`. Takes no conversion, or a selector. | Without a selector it uses the registered converters. The view must implement `IViewFor`. |
+| [`BindUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.Binding.Unsafe.cs) | Carries a property both ways, called on the view. | Returns `IReactiveBinding<TView, BindingChange>`. Takes no conversion, two conversion `Func` values, or an update stream `IObservable<TDontCare>?` with a `TriggerUpdate`. | Writes the view model value to the view first. Without conversion functions it uses the registered converters, and a value they cannot convert is written as the default. A null stream observes both properties. |
+| [`BindToUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.BindTo.Unsafe.cs) | Writes each value of a stream to a target property. | Extension on `IObservable<TValue>`. Returns `IDisposable`. Takes no extras, a hint `object?`, an `IBindingTypeConverter?`, or both. | A null target writes nothing. A value the converter cannot convert is written as the default. A null source throws `ArgumentNullException`. |
+| [`BindCommandUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.BindCommand.Unsafe.cs) | Connects the command a property holds to a control. | Returns `IDisposable`. Takes an event name `string?`, plus an `IObservable<TParam?>` or a parameter expression for the command parameter. | A null event name picks the control's default event. Nothing is bound while the view model, the command or the control is null, or when no registered binder supports the control. |
+| [`InvokeCommandUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.InvokeCommand.Unsafe.cs) | Runs the command a property holds for each value of a stream. | Extension on `IObservable<T>`. Returns `IDisposable`. | Skips a value while there is no command or the command cannot run. A null target runs nothing. A null source or command path throws `ArgumentNullException`. |
+| [`BindInteractionUnsafe`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveUIBindingExtensions.BindInteraction.Unsafe.cs) | Registers a handler on the interaction a property holds. | Returns `IDisposable`. The handler is a `Func` returning `Task`, or returning `IObservable<TDontCare>`. | Moves the handler when the property holds another interaction. A null view model registers nothing. |
+| [`ReactiveSchedulerExtensions`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/ReactiveSchedulerExtensions.Unsafe.cs) | Holds the twins of `BindOneWay`, `BindTwoWay`, `OneWayBind` and `Bind` that take a sequencer. | Static class in `ReactiveUI.Binding`. Each twin takes an `ISequencer?` after the expressions and any conversion `Func`. A converter form takes the converters, the sequencer, then an `object?` hint. | A null sequencer writes on the target's owning thread. An immediate sequencer writes inline. A two-way twin does not schedule the write back. |
+| [`TriggerUpdate`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/TriggerUpdate.cs) | Selects the direction that an update stream drives. | Enum in `ReactiveUI.Binding`. Values below. | The optional last argument of the `BindUnsafe` forms that take an update stream. |
+| [`TriggerUpdate.ViewToViewModel`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/TriggerUpdate.cs) | The stream replaces view notifications and requests writes to the view model. | `0`; the default. | View model changes reach the view at once. |
+| [`TriggerUpdate.ViewModelToView`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Bindings/TriggerUpdate.cs) | The stream requests writes to the view in place of view model notifications after the first. | `1` | The first view model value is written when the binding starts. View notifications are observed and reach the view model at once. |
+| [`RuntimeObservationFallback.WhenChanged`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/RuntimeObservationFallback.cs) | Observes one to three property expressions and delivers each value after it changes. | Static method in `ReactiveUI.Binding.Fallback`. Takes up to three paths, up to `PropertyValues<T1, T2, T3>`. | Delivers the current value first and skips a value equal to the one before. A null link on a path delivers nothing until the path resolves. The type is hidden from IntelliSense. |
+| [`RuntimeObservationFallback.WhenChanging`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/RuntimeObservationFallback.cs) | Observes one to three property expressions and delivers each value before it changes. | Takes up to three paths, up to `PropertyValues<T1, T2, T3>`. | The object must raise `INotifyPropertyChanging`. |
+| [`RuntimeObservationFallback.WhenAnyValue`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/RuntimeObservationFallback.cs) | Observes one to three property expressions and delivers each value after it changes. | Takes up to three paths, up to `PropertyValues<T1, T2, T3>`. | Delivers the current value first. |
+| [`RuntimeBindingFallback.BindOneWay`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/RuntimeBindingFallback.cs) | Binds a source property one way onto a target property. | Returns `IDisposable`. Takes the same type, or a conversion `Func`, then an `ISequencer?` and the expression text. | A null sequencer writes on the thread that owns the target. A null conversion throws `ArgumentNullException`. |
+| [`RuntimeBindingFallback.BindTwoWay`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/RuntimeBindingFallback.cs) | Binds two properties to each other. | Returns `IDisposable`. Takes the same type, or a `TwoWayConverterPair`, then an `ISequencer?` and the expression text. | Only the write to the target uses the sequencer. A null pair throws `ArgumentNullException`. |
+| [`RuntimeBindingFallback.OneWayBind`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/RuntimeBindingFallback.cs) | Binds a view model property one way onto a view property, starting from the view. | Returns `IReactiveBinding<TView, TProp>`. Takes the same type, or a conversion `Func`, then an `ISequencer?` and the expression text. | A null conversion throws `ArgumentNullException`. |
+| [`RuntimeBindingFallback.Bind`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/RuntimeBindingFallback.cs) | Binds a view model property and a view property to each other, starting from the view. | Returns `IReactiveBinding<TView, BindingChange>`. Takes the same type, or a `TwoWayConverterPair`, then an `ISequencer?` and the expression text. Two more forms end with an update stream and a `TriggerUpdate` instead. | A null pair throws `ArgumentNullException`. The forms with an update stream take no sequencer and no expression text. |
+| [`RuntimeBindingFallback.BindTo`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/RuntimeBindingFallback.cs) | Writes each value of a stream into a property. | Returns `IDisposable`. Takes a hint `object?`, an `IBindingTypeConverter?`, an `ISequencer?` and the expression text. | A null target drops the values. A value the converter refuses is written as the default of the property type. A null source or property throws `ArgumentNullException`. |
+| [`RuntimeBindingConverter.TryConvert`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/RuntimeBindingConverter.cs) | Converts a value from one type to another. | Returns `bool`. Takes the value, a hint `object?`, an `IBindingTypeConverter?` override and an `out` result. | A converter you pass wins over the registered ones. Returns `false` and the default when no converter can convert. The converter is chosen from the declared types, not the runtime type. |
+| [`RuntimeCommandBindingFallback.BindCommand`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/RuntimeCommandBindingFallback.cs) | Keeps the command a property holds bound to a control. | Returns `IDisposable`. Takes an `IObservable<object?>` of parameters, an event name `string?` and the expression text. | Rebinds when either property changes. Nothing is bound while the view model, the command or the control is null. A null command or control path throws `ArgumentNullException`. |
+| [`RuntimeCommandFallback.InvokeCommand`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/RuntimeCommandFallback.cs) | Runs the command a property holds for each value of a stream. | Returns `IDisposable`. Takes a stream, a target and a command path. | A null target drops the values. A null source or path throws `ArgumentNullException`. |
+| [`RuntimeInteractionFallback.BindInteraction`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/RuntimeInteractionFallback.cs) | Keeps a handler registered on the interaction a property holds. | Returns `IDisposable`. Takes a view model, an interaction path, a `Func` that registers the handler and returns `IDisposable`, and the expression text. | Moves the handler when the property holds another interaction. A null view model registers nothing. A null path or callback throws `ArgumentNullException`. |
+| [`TwoWayConverters.Create`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/TwoWayConverters.cs) | Pairs a forward and a reverse conversion. | Returns `TwoWayConverterPair<TSourceProp, TTargetProp>`. Takes two `Func` values. | Infers both type arguments. |
+| [`TwoWayConverterPair<TSourceProp, TTargetProp>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/TwoWayConverterPair.cs) | Holds the two conversions a two-way binding needs. | Sealed record with the properties `Forward` and `Reverse`. | Two pairs with the same functions are equal. `with` replaces one function. |
+| [`TwoWayConverterPair.Forward`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/TwoWayConverterPair.cs) | Converts a source value to the target's type. | `Func<TSourceProp, TTargetProp>` | Set it with `with`. |
+| [`TwoWayConverterPair.Reverse`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Fallback/TwoWayConverterPair.cs) | Converts a target value back to the source's type. | `Func<TTargetProp, TSourceProp>` | Set it with `with`. |
+| [`Reflection.ExpressionToPropertyNames`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/Reflection.cs) | Names the links of a path, joined by dots. | Static method in `ReactiveUI.Binding.Expressions`. Returns `string`. | An indexer link needs constant arguments. A null expression throws `ArgumentNullException`. A node that is not a member access or an index throws `NotSupportedException`. |
+| [`Reflection.Rewrite`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/Reflection.cs) | Rewrites a path into the plain shape the other members read. | Takes and returns `Expression`. | Removes conversions and turns an indexer call into an indexer link. Returns null for a null expression. |
+| [`Reflection.GetValueFetcherForProperty`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/Reflection.cs) | Builds a method that reads a property or a field. | Returns `Func<object?, object?[]?, object?>?`. | Returns `null` for a member that is neither. The fetcher for a field throws `InvalidOperationException` when the field holds null. A null member throws `ArgumentNullException`. |
+| [`Reflection.GetValueFetcherOrThrow`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/Reflection.cs) | Builds a method that reads a property or a field. | Returns `Func<object?, object?[]?, object?>`. | Throws `ArgumentException` for a member that is neither. |
+| [`Reflection.GetValueSetterForProperty`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/Reflection.cs) | Builds a method that writes a property or a field. | Returns `Action<object?, object?, object?[]?>?`. The arguments are the object, the value and the indexer arguments. | Returns `null` for a member that is neither. A null member throws `ArgumentNullException`. |
+| [`Reflection.GetValueSetterOrThrow`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/Reflection.cs) | Builds a method that writes a property or a field. | Returns `Action<object?, object?, object?[]?>`. | Throws `ArgumentException` for a member that is neither. |
+| [`Reflection.TryGetValueForPropertyChain`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/Reflection.cs) | Reads the value at the end of a path. | Returns `bool`. Takes an `out` value, the start object and the links. | Returns `false` and the default when the start object or a link is null. An empty chain throws `InvalidOperationException`. |
+| [`Reflection.TryGetAllValuesForPropertyChain`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/Reflection.cs) | Reads the value of every link. | Returns `bool`. Fills an `out` array of `IObservedChange<object, object?>`, one entry per link. | Entries from the first null link on are `null`, and the method returns `false`. An empty chain throws `InvalidOperationException`. |
+| [`Reflection.TrySetValueToPropertyChain`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/Reflection.cs) | Writes the value at the end of a path. | Returns `bool`. Takes the start object, the links, the value, and an optional `shouldThrow` `bool`. | Returns `false` when the object that owns the last property is null. A null link before that throws `ArgumentNullException`. With `shouldThrow` set to `false` it skips a link that is not a property or a field. |
+| [`ExpressionMixins.GetExpressionChain`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/ExpressionMixins.cs) | Splits a path into its links, from the root outwards. | Extension on `Expression`. Returns `IEnumerable<Expression>`. | Empty for a parameter or a null expression. A node that is not a member access or an index throws `NotSupportedException`. |
+| [`ExpressionMixins.GetMemberInfo`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/ExpressionMixins.cs) | Finds the member a link names. | Returns `MemberInfo?`. | Looks through a conversion. A null expression throws `ArgumentNullException`, and a node that is not an index, a member access or a conversion throws `NotSupportedException`. |
+| [`ExpressionMixins.GetParent`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/ExpressionMixins.cs) | Finds the expression a link is read from. | Returns `Expression?`. | Returns `null` for a static member. Anything but an index or a member access throws `NotSupportedException`. |
+| [`ExpressionMixins.GetArgumentsArray`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Expression/ExpressionMixins.cs) | Reads the arguments of an indexer link. | Returns `object?[]?`. | Returns `null` for a link that is not an indexer. A non-constant argument throws `InvalidCastException`. |
diff --git a/docs/documentation/binding/views.md b/docs/documentation/binding/views.md
new file mode 100644
index 00000000..80aba524
--- /dev/null
+++ b/docs/documentation/binding/views.md
@@ -0,0 +1,1008 @@
+---
+Order: 7
+---
+# Views
+
+[Run the complete page example](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/views/views.csproj).
+
+An application shows a screen for each view model. A navigation service holds a to-do list view model
+and has to ask: which screen shows this? A *view* is the class for that screen. A *view locator* is the object
+that answers the question. You give it a view model and it gives you the view, with the view model already set.
+
+ReactiveUI.Binding writes most of that lookup for you. The [source generator](index.md) finds every class that
+implements `IViewFor<T>` and writes a lookup for them while your project builds. You can also register views
+by hand, and you can choose between several screens for one view model.
+
+This page starts with one view and one lookup. Later sections cover the interfaces a view implements,
+the locator and its errors, contracts, the generated lookup, hand-written mappings and the order the locator checks.
+
+## Find the view for a view model
+
+**1. Implement `IViewFor<T>`.** A view declares the type of view model it shows. `IViewFor<T>` has one
+member, a typed `ViewModel` property. Its base interface, `IViewFor`, has the same property typed as `object`.
+Implement the base one explicitly and forward it to the typed one.
+
+```csharp
+public sealed class AccountListView : ObservableObject, IViewFor<IAccountList>
+{
+    public IAccountList? ViewModel
+    {
+        get;
+        set => SetProperty(ref field, value);
+    }
+
+    public Label CountLabel { get; } = new();
+
+    object? IViewFor.ViewModel
+    {
+        get => ViewModel;
+        set => ViewModel = (IAccountList?)value;
+    }
+}
+```
+
+`ObservableObject` is a helper class from the examples that raises `PropertyChanged`. A view should raise a
+change when its `ViewModel` changes, because bindings follow that property.
+This view names an interface, `IAccountList`, as its view model type. That choice matters in the next step.
+
+**2. Resolve a view.** Create a `DefaultViewLocator` and pass it a view model. `ResolveView` returns the view with
+its `ViewModel` set to the object you passed.
+
+```csharp
+AccountListViewModel current = new([CreateAccount(EverydayId, EverydayName)]);
+ClosedAccountListViewModel closed = new([]);
+DefaultViewLocator locator = new();
+
+var currentView = locator.ResolveView(current);
+var closedView = locator.ResolveView(closed);
+
+Console.WriteLine(currentView?.GetType().Name);
+Console.WriteLine(closedView?.GetType().Name);
+Console.WriteLine(ReferenceEquals(closedView?.ViewModel, closed));
+```
+
+```text
+AccountListView
+AccountListView
+True
+```
+
+**3. Read the result.** Both view models implement `IAccountList`, so one view serves both. You wrote no
+registration code. The generator saw `AccountListView` and added it to the lookup. `ResolveView` returns
+`null` when no view matches, so check for it.
+
+## Give a view its view model
+
+A host, such as a navigation service, hands a view model to a view through the interface. It does not know the
+concrete view type. `Present` takes the typed interface and reads the property back.
+
+```csharp
+public static TViewModel? Present<TViewModel>(IViewFor<TViewModel> view, TViewModel viewModel)
+    where TViewModel : class
+{
+    view.ViewModel = viewModel;
+    return view.ViewModel;
+}
+```
+
+The next snippet shows a new to-do view before and after the host presents a view model to it. A view starts
+empty, so it only shows data once the host assigns one.
+
+```csharp
+TodoView view = new();
+TodoListViewModel viewModel = new(InMemoryTodoStore.CreateSeeded());
+
+Console.WriteLine(view.ViewModel is null);
+
+var shown = Present(view, viewModel);
+
+Console.WriteLine(ReferenceEquals(shown, viewModel));
+Console.WriteLine(ReferenceEquals(view.ViewModel, viewModel));
+```
+
+```text
+True
+True
+True
+```
+
+### Assign through the non-generic interface
+
+A navigation stack often holds view models as `object`. `IViewFor` takes an `object`, so the host needs no
+generic type argument.
+
+```csharp
+IssueBoardView view = new();
+IssueBoardViewModel viewModel = new(InMemoryGitHubServer.CreateSeeded());
+var screen = (IViewFor)view;
+
+screen.ViewModel = viewModel;
+
+Console.WriteLine(ReferenceEquals(screen.ViewModel, viewModel));
+Console.WriteLine(ReferenceEquals(view.ViewModel, viewModel));
+```
+
+```text
+True
+True
+```
+
+The forwarding property casts the object to the view model type. A view model of the wrong type throws
+`InvalidCastException`, and the view keeps its old value.
+
+```csharp
+var screen = (IViewFor)new IssueBoardView();
+TodoListViewModel wrongViewModel = new(InMemoryTodoStore.CreateSeeded());
+var refused = false;
+
+try
+{
+    screen.ViewModel = wrongViewModel;
+}
+catch (InvalidCastException)
+{
+    refused = true;
+}
+
+Console.WriteLine(refused);
+Console.WriteLine(screen.ViewModel is null);
+```
+
+```text
+True
+True
+```
+
+### Observe the view model of a view
+
+The `ViewModel` property is an ordinary property, so you observe it like any other. `WhenChanged` delivers the
+current value on subscribe and then each change. See [observing](observing.md) for how that works.
+
+```csharp
+TodoView view = new();
+TodoListViewModel viewModel = new(InMemoryTodoStore.CreateSeeded());
+List<TodoListViewModel?> shown = [];
+
+using (view.WhenChanged(x => x.ViewModel!).Subscribe(shown.Add))
+{
+    view.ViewModel = viewModel;
+}
+
+Console.WriteLine(shown.Count);
+Console.WriteLine(shown[0] is null);
+Console.WriteLine(ReferenceEquals(shown[1], viewModel));
+```
+
+```text
+2
+True
+True
+```
+
+The first value is `null` because the view had no view model when the subscription began.
+
+### Recognize activatable views
+
+`IActivatableView` is a marker interface. It has no members, and every `IViewFor` implements it. A host uses it
+to tell views from other objects.
+
+```csharp
+public static int CountActivatable(IEnumerable<object> candidates) => candidates.OfType<IActivatableView>().Count();
+```
+
+The next snippet puts two views and one view model in a list and counts the activatable items. Only the views
+count, so the check separates screens from data.
+
+```csharp
+List<object> candidates =
+[
+    new TodoView(),
+    new TodoListViewModel(InMemoryTodoStore.CreateSeeded()),
+    new AccountsView(),
+];
+
+Console.WriteLine(CountActivatable(candidates));
+```
+
+```text
+2
+```
+
+## Bind a view to its view model
+
+The view-first binding methods, `OneWayBind` and `Bind`, take the view model and two property paths. They need a
+view that implements `IViewFor`. The bindings follow `view.ViewModel`, so show the view model in the view first.
+Then bind. Read [bindings](bindings.md) for the full set of binding methods.
+
+```csharp
+TodoListViewModel viewModel = new(InMemoryTodoStore.CreateSeeded());
+TodoView view = new();
+await viewModel.LoadAsync();
+
+// The bindings follow view.ViewModel, so the screen has to show the view model first.
+_ = Present(view, viewModel);
+
+using (view.OneWayBind(viewModel, x => x.RemainingCount, v => v.RemainingLabel.Text, static count => count.ToString(CultureInfo.InvariantCulture)))
+using (view.Bind(viewModel, x => x.NewTitle, v => v.NewTitleTextBox.Text))
+{
+    Console.WriteLine(view.RemainingLabel.Text);
+
+    view.NewTitleTextBox.Text = NewItemTitle;
+
+    Console.WriteLine(viewModel.NewTitle);
+}
+```
+
+```text
+3
+Book vet appointment
+```
+
+`OneWayBind` copies the remaining count to the label. `Bind` carries the text the user types back into the view
+model. `BindAccountsView` in the [example project](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/views/ViewForExamples.cs)
+does the same for a banking screen. Every binding writes to the view on the thread that owns it. See
+[threading](threading.md).
+
+## Use the locator your application registers
+
+`new DefaultViewLocator()` is fine in a test. An application registers one locator for everyone to share.
+`ViewLocator.GetCurrent()` returns that locator. `WithCoreServices` registers a `DefaultViewLocator` among the
+core services. The example calls it and then `BuildApp`. See [setup](setup.md) for the builder.
+
+```csharp
+var builder = (IReactiveUIBindingBuilder)RxBindingBuilder.CreateReactiveUIBindingBuilder();
+_ = builder.WithCoreServices().BuildApp();
+
+var locator = ViewLocator.GetCurrent();
+
+Console.WriteLine(locator is DefaultViewLocator);
+```
+
+```text
+True
+```
+
+The locator is an `IViewLocator`. Asking for it before any registration throws `ViewLocatorNotFoundException`.
+The message names the calls that fix it.
+
+```csharp
+ViewLocatorNotFoundException? failure = null;
+
+try
+{
+    _ = ViewLocator.GetCurrent();
+}
+catch (ViewLocatorNotFoundException ex)
+{
+    failure = ex;
+}
+
+Console.WriteLine(failure is not null);
+Console.WriteLine(failure!.Message.Contains("WithCoreServices", StringComparison.Ordinal));
+```
+
+```text
+True
+True
+```
+
+The next snippet asks the registered locator for the screen of a to-do list. It returns `TodoView` with the view
+model set, which is what a navigation service needs before it shows the screen.
+
+```csharp
+TodoListViewModel viewModel = new(InMemoryTodoStore.CreateSeeded());
+var locator = ViewLocator.GetCurrent();
+
+var view = locator.ResolveView(viewModel);
+
+Console.WriteLine(view?.GetType().Name);
+Console.WriteLine(ReferenceEquals(view?.ViewModel, viewModel));
+```
+
+```text
+TodoView
+True
+```
+
+## Resolve views
+
+`IViewLocator` declares two overloads of `ResolveView`. Each takes a contract, a string that picks between
+screens for one view model. Pass `null` for the default screen. Contracts are covered [below](#choose-a-view-by-contract).
+
+| Member | Use it when |
+|--------|-------------|
+| `ResolveView<TViewModel>(viewModel, contract)` | You know the view model type when you write the call. |
+| `ResolveView(object, contract)` | You hold the view model as an `object`. |
+| `ResolveView(viewModel)` | You want the default contract. `ViewLocatorMixins` adds this to both forms. |
+
+The generic overload reads the view model type at compile time. It is safe for Native AOT. The `object`
+overload reads the runtime type. When no generated or mapped view answers, it closes `IViewFor<>` over that
+runtime type to ask the service locator. That step needs code the compiler never saw, so the `object` overloads carry
+`[RequiresDynamicCode]`. In an AOT application, use the generic overload or register the view.
+
+A *service locator* is a shared registry where an application registers services by type. This library uses
+Splat's `AppLocator` for that.
+
+The next snippet holds an issue board view model in an `object` variable, as a navigation stack does. The
+compiler picks the `object` overload, so the call needs no cast and no type argument.
+
+```csharp
+object viewModel = new IssueBoardViewModel(InMemoryGitHubServer.CreateSeeded());
+var locator = ViewLocator.GetCurrent();
+
+var view = locator.ResolveView(viewModel);
+
+Console.WriteLine(view?.GetType().Name);
+Console.WriteLine(ReferenceEquals(view?.ViewModel, viewModel));
+```
+
+```text
+IssueBoardView
+True
+```
+
+A host that passes a contract calls the interface directly. The helper below forwards a contract for an
+`object` view model.
+
+```csharp
+public static IViewFor? ResolveForContract(IViewLocator locator, object viewModel, string? contract) =>
+    locator.ResolveView(viewModel, contract);
+```
+
+The next snippet uses that helper to ask for the accounts screen with and without a contract. The default screen
+and the compact screen come back, so a host can pick a layout by name.
+
+```csharp
+object viewModel = new AccountsViewModel(new InMemoryBankingBackend());
+DefaultViewLocator locator = new();
+
+var standard = ResolveForContract(locator, viewModel, null);
+var compact = ResolveForContract(locator, viewModel, AccountViewContracts.Compact);
+
+Console.WriteLine(standard?.GetType().Name);
+Console.WriteLine(compact?.GetType().Name);
+```
+
+```text
+AccountsView
+CompactAccountsView
+```
+
+The next snippet resolves a view for a `null` view model. It returns `null` and does not throw, so a host can
+pass a missing view model safely. Both overloads behave this way.
+
+```csharp
+var locator = ViewLocator.GetCurrent();
+
+var view = locator.ResolveView((object?)null);
+
+Console.WriteLine(view is null);
+```
+
+```text
+True
+```
+
+## Handle a missing view
+
+A view model with no view resolves to `null`. The locator does not throw, because a missing view is often
+normal. A host that needs a screen decides what to do. This helper turns `null` into a
+`ViewLocatorNotFoundException` with a message for the user.
+
+```csharp
+public static IViewFor RequireView(IViewLocator locator, object viewModel)
+{
+    var view = locator.ResolveView(viewModel);
+    return view ?? throw new ViewLocatorNotFoundException($"No screen is registered for {viewModel.GetType().Name}.");
+}
+```
+
+The next snippet asks for the screen of a to-do item that has none. The plain call returns `null`, and
+`RequireView` throws with its message. That shows both ways a host can react.
+
+```csharp
+TodoItem note = new() { Title = NoteTitle };
+var locator = ViewLocator.GetCurrent();
+ViewLocatorNotFoundException? failure = null;
+
+var view = locator.ResolveView(note);
+
+try
+{
+    _ = RequireView(locator, note);
+}
+catch (ViewLocatorNotFoundException ex)
+{
+    failure = ex;
+}
+
+Console.WriteLine(view is null);
+Console.WriteLine(failure?.Message);
+```
+
+```text
+True
+No screen is registered for TodoItem.
+```
+
+A view that exists but fails to build is a different case. The locator does not catch the exception from a view
+constructor or a factory. It reaches your code. This helper reports the failure as a missing screen and keeps the
+cause in `InnerException`.
+
+```csharp
+public static IViewFor? ResolveOrExplain(IViewLocator locator, TodoItem viewModel)
+{
+    try
+    {
+        return locator.ResolveView(viewModel);
+    }
+    catch (InvalidOperationException ex)
+    {
+        throw new ViewLocatorNotFoundException($"The screen for {nameof(TodoItem)} could not be built.", ex);
+    }
+}
+```
+
+The next snippet maps a factory that throws, then resolves through the helper. The caller sees the not-found
+exception with the original error inside it, so the cause is not lost.
+
+```csharp
+TodoItem viewModel = new() { Title = NoteTitle };
+DefaultViewLocator locator = new();
+locator.Map<TodoItem>(static () => throw new InvalidOperationException(LayoutFailure));
+ViewLocatorNotFoundException? failure = null;
+
+try
+{
+    _ = ResolveOrExplain(locator, viewModel);
+}
+catch (ViewLocatorNotFoundException ex)
+{
+    failure = ex;
+}
+
+Console.WriteLine(failure?.Message);
+Console.WriteLine(failure?.InnerException?.Message);
+```
+
+```text
+The screen for TodoItem could not be built.
+The layout file is missing.
+```
+
+`ViewLocatorNotFoundException` has three constructors: one with no arguments, one with a message and one with a
+message and an inner exception. The one with no arguments carries a message that names the builder calls
+that register the locator.
+
+```csharp
+ViewLocatorNotFoundException failure = new();
+
+Console.WriteLine(failure.Message.Contains("BuildApp", StringComparison.Ordinal));
+```
+
+```text
+True
+```
+
+## Write your own locator
+
+`IViewLocator` is a small interface. An application with one screen can implement it directly. Both overloads
+return the view for a to-do list and `null` for anything else.
+
+```csharp
+public sealed class TodoViewLocator : IViewLocator
+{
+    public IViewFor? ResolveView(object? viewModel, string? contract) =>
+        viewModel is TodoListViewModel todoList ? new TodoView { ViewModel = todoList } : null;
+
+    public IViewFor? ResolveView<TViewModel>(TViewModel viewModel, string? contract)
+        where TViewModel : class =>
+        viewModel is TodoListViewModel todoList ? new TodoView { ViewModel = todoList } : null;
+}
+```
+
+The next snippet resolves the to-do list and an unrelated item through it. The list gets its screen with the view
+model set and the other item gets `null`, so a custom locator behaves like the default one.
+
+```csharp
+TodoListViewModel viewModel = new(InMemoryTodoStore.CreateSeeded());
+TodoViewLocator locator = new();
+
+var view = locator.ResolveView(viewModel, null);
+var missing = locator.ResolveView(new TodoItem(), null);
+
+Console.WriteLine(view?.GetType().Name);
+Console.WriteLine(ReferenceEquals(view?.ViewModel, viewModel));
+Console.WriteLine(missing is null);
+```
+
+```text
+TodoView
+True
+True
+```
+
+## Choose a view by contract
+
+One view model can have more than one screen. A *contract* is a string that names one of them. Put
+`[ViewContract]` on a view to register it under a contract. A view with no attribute is the default screen.
+The next snippet reads the contract back from the attribute with reflection. It shows the string the view is
+registered under, which is the string a caller passes to `ResolveView`.
+
+```csharp
+var attribute = typeof(AccountStatementView).GetCustomAttribute<ViewContractAttribute>();
+
+Console.WriteLine(attribute?.Contract);
+```
+
+```text
+statement
+```
+
+`AccountStatementView` and `AccountSummaryView` both show an `Account`. The statement view carries
+`[ViewContract(AccountViewContracts.Statement)]`. The summary view has no contract. Pass the contract to
+`ResolveView` to choose.
+
+```csharp
+var account = CreateAccount();
+DefaultViewLocator locator = new();
+
+var statement = locator.ResolveView(account, AccountViewContracts.Statement);
+var summary = locator.ResolveView(account, null);
+
+Console.WriteLine(statement?.GetType().Name);
+Console.WriteLine(summary?.GetType().Name);
+```
+
+```text
+AccountStatementView
+AccountSummaryView
+```
+
+The next snippet asks for a contract that no view claims. The locator returns the default screen instead of
+nothing, so an unknown contract still shows a sensible screen.
+
+```csharp
+var account = CreateAccount();
+DefaultViewLocator locator = new();
+
+var view = locator.ResolveView(account, UnclaimedContract);
+
+Console.WriteLine(view?.GetType().Name);
+```
+
+```text
+AccountSummaryView
+```
+
+Two more rules follow from how the generator writes the lookup. A view model that has only one registered view,
+with no contract, answers to every contract. A view model whose only view has a contract answers to that
+contract and no other. `ResolveBankingViewByContract` in the
+[example project](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/examples/Documentation/Pages/views/ViewContractExamples.cs)
+picks `AccountsView` or `CompactAccountsView` for `AccountsViewModel` this way.
+
+## The generated view dispatch
+
+The generator writes one lookup for each assembly that contains views. Each entry pairs a view model type with a
+view and a contract. The lookup is a type switch, so it uses no reflection and works with trimming and Native AOT.
+This lookup is the *view dispatch*: it chooses which view to build for a view model.
+
+A few facts describe how the generated lookup behaves.
+
+- **It prefers the service locator.** The generated resolver for a view asks the service locator first.
+  When the service locator has no view, the resolver builds the view with its parameterless constructor.
+- **It registers itself.** From C# 9 the registration runs in a module initializer, before any code in the
+  assembly. In older projects it runs when a binding first uses the generated class.
+- **It keeps one view for each pair of view model and contract.** The first registration in source order wins.
+- **It skips open generic views.** That includes a view nested in an open generic type.
+- **Assemblies stack.** `DefaultViewLocator` keeps the lookup of each assembly, in registration order, and asks
+  the most recent first. When two assemblies both have a view for the same view model, the assembly that
+  registered last wins.
+
+### Reuse one view
+
+`[SingleInstanceView]` tells the lookup to build a view once and hand out the same instance every time. Each
+resolve sets the latest view model on that instance. Use it only for a view that is not shown in more than one
+place at once.
+
+```csharp
+var everyday = CreateAccount(EverydayId, EverydayName);
+var savings = CreateAccount(SavingsId, SavingsName);
+DefaultViewLocator locator = new();
+
+var first = locator.ResolveView(everyday);
+var second = locator.ResolveView(savings);
+
+Console.WriteLine(first?.GetType().Name);
+Console.WriteLine(ReferenceEquals(first, second));
+Console.WriteLine(ReferenceEquals(first?.ViewModel, savings));
+```
+
+```text
+AccountSummaryView
+True
+True
+```
+
+### Leave a view out
+
+`[ExcludeFromViewRegistration]` keeps a view out of the lookup. Nothing answers until the application maps the
+view by hand. The next sections show `Map`.
+
+```csharp
+var item = new TodoItem { Title = "Renew car registration" };
+DefaultViewLocator locator = new();
+
+var before = locator.ResolveView(item);
+locator.Map<TodoItem, TodoItemPreviewView>();
+var after = locator.ResolveView(item);
+
+Console.WriteLine(before is null);
+Console.WriteLine(after?.GetType().Name);
+```
+
+```text
+True
+TodoItemPreviewView
+```
+
+### Register a view that needs arguments
+
+`ReceiptView` has no parameterless constructor, so the lookup cannot build it. The lookup finds it only when
+the service locator holds it. Register the view with `AppLocator`, and unregister it when you finish.
+
+```csharp
+TransferReceipt receipt = new("RCPT-000001", TransferAmount, AccountBalance - TransferAmount, DateTimeOffset.UnixEpoch);
+DefaultViewLocator locator = new();
+
+var before = locator.ResolveView(receipt);
+AppLocator.CurrentMutable.Register<IViewFor<TransferReceipt>>(static () => new ReceiptView(ReceiptHeading));
+
+try
+{
+    var after = (ReceiptView?)locator.ResolveView(receipt);
+
+    Console.WriteLine(before is null);
+    Console.WriteLine(after?.HeadingLabel.Text);
+    Console.WriteLine(ReferenceEquals(after?.ViewModel, receipt));
+}
+finally
+{
+    AppLocator.CurrentMutable.UnregisterAll<IViewFor<TransferReceipt>>();
+}
+```
+
+```text
+True
+Transfer receipt
+True
+```
+
+### Register a view for an interface
+
+The generated lookup tests the view model with `is`, so a view registered for an interface serves every
+class that implements it. You saw this in the first walkthrough. A view model can also have a view for its own
+class next to the interface view. The lookup tests registrations in source-file order and returns the first
+match. Nothing reports the overlap.
+
+```csharp
+AccountListViewModel current = new([CreateAccount(EverydayId, EverydayName)]);
+DefaultViewLocator locator = new();
+
+var view = locator.ResolveView(current);
+
+Console.WriteLine(view?.GetType().Name);
+Console.WriteLine(view is DetailedAccountListView);
+```
+
+```text
+AccountListView
+False
+```
+
+Here the interface view comes first, so `DetailedAccountListView` is never returned. Give one of the two a contract,
+or map it by hand, when you want both.
+
+### Register a lookup of your own
+
+`DefaultViewLocator.SetGeneratedViewDispatch` is the method the generated code calls. You can call it yourself
+with a function that takes a view model and a contract. Return `null` for anything the function does not know.
+Editors hide the method from completion lists, because generated code is its intended caller.
+
+```csharp
+var item = new TodoItem { Title = "Renew car registration" };
+DefaultViewLocator locator = new();
+
+var before = locator.ResolveView(item, PreviewCardContract);
+
+DefaultViewLocator.SetGeneratedViewDispatch(static (viewModel, contract) =>
+    viewModel is TodoItem && contract == PreviewCardContract ? new TodoItemPreviewView() : null);
+
+var after = locator.ResolveView(item, PreviewCardContract);
+var otherContract = locator.ResolveView(item, null);
+
+Console.WriteLine(before is null);
+Console.WriteLine(after?.GetType().Name);
+Console.WriteLine(ReferenceEquals(after?.ViewModel, item));
+Console.WriteLine(otherContract is null);
+```
+
+```text
+True
+TodoItemPreviewView
+True
+True
+```
+
+The lookup is shared by every `DefaultViewLocator` in the process. Adding it once is enough, and adding the
+same function again has no effect.
+
+## Map views by hand
+
+`Map` registers a view on one locator. Use it for a view the generator skips, or for a view you choose at
+run time. A mapping belongs to the locator instance you call it on. Calling `Map` again for the same view model
+and contract replaces the old mapping.
+
+| Member | What it registers |
+|--------|-------------------|
+| `Map<TViewModel, TView>()` | A view built with its parameterless constructor. |
+| `Map<TViewModel, TView>(contract)` | The same view under a contract. |
+| `Map<TViewModel>(factory)` | A view built by a factory. |
+| `Map<TViewModel>(factory, contract)` | A factory under a contract. |
+| `Unmap<TViewModel>()` and `Unmap<TViewModel>(contract)` | Removes a mapping. |
+
+The next snippet maps the preview view for a to-do item and resolves it. The locator builds the view with its
+parameterless constructor and sets the view model, so a view the generator skips still works.
+
+```csharp
+var item = CreateItem();
+DefaultViewLocator locator = new();
+
+locator.Map<TodoItem, TodoItemPreviewView>();
+
+var view = locator.ResolveView(item);
+
+Console.WriteLine(view?.GetType().Name);
+Console.WriteLine(ReferenceEquals(view?.ViewModel, item));
+```
+
+```text
+TodoItemPreviewView
+True
+```
+
+Add a contract, and the mapping answers only to that contract.
+
+```csharp
+var item = CreateItem();
+DefaultViewLocator locator = new();
+
+locator.Map<TodoItem, TodoItemPreviewView>(PreviewContract);
+
+var preview = locator.ResolveView(item, PreviewContract);
+var plain = locator.ResolveView(item, null);
+
+Console.WriteLine(preview?.GetType().Name);
+Console.WriteLine(plain is null);
+```
+
+```text
+TodoItemPreviewView
+True
+```
+
+Use a factory for a screen that needs setup before it is shown. The locator calls the factory on every resolve,
+so each call gets a new view.
+
+```csharp
+var item = CreateItem();
+DefaultViewLocator locator = new();
+
+locator.Map<TodoItem>(static () => new TodoItemPreviewView { IsCompact = true });
+
+var view = (TodoItemPreviewView?)locator.ResolveView(item);
+
+Console.WriteLine(view?.IsCompact);
+Console.WriteLine(ReferenceEquals(view?.ViewModel, item));
+```
+
+```text
+True
+True
+```
+
+`Unmap` removes a mapping and returns `true` when one existed. A `null` contract removes the default mapping.
+
+```csharp
+var item = CreateItem();
+DefaultViewLocator locator = new();
+locator.Map<TodoItem, TodoItemPreviewView>();
+locator.Map<TodoItem, TodoItemPreviewView>(PreviewContract);
+
+var removedDefault = locator.Unmap<TodoItem>();
+var removedAgain = locator.Unmap<TodoItem>();
+var removedContract = locator.Unmap<TodoItem>(PreviewContract);
+
+Console.WriteLine(removedDefault);
+Console.WriteLine(removedAgain);
+Console.WriteLine(removedContract);
+Console.WriteLine(locator.ResolveView(item) is null);
+```
+
+```text
+True
+False
+True
+True
+```
+
+A mapping matches the exact type you register. The generic `ResolveView` reads that type from the
+compile-time type of the variable you pass. The `object` overload reads it from the runtime type. A mapping for
+an interface matches only when the call is typed as that interface.
+
+### Chain mappings with the builder
+
+`CreateMappingBuilder` returns a `ViewMappingBuilder`. It has the same four `Map` overloads, and each returns the
+builder so that you can chain them.
+
+```csharp
+var item = CreateItem();
+DefaultViewLocator locator = new();
+
+_ = locator.CreateMappingBuilder()
+    .Map<TodoItem, TodoItemPreviewView>()
+    .Map<TodoItem, TodoItemDetailView>(DetailContract)
+    .Map<TodoItem>(static () => new TodoItemPreviewView { IsCompact = true }, CompactContract);
+
+var standard = locator.ResolveView(item, null);
+var detail = locator.ResolveView(item, DetailContract);
+var compact = (TodoItemPreviewView?)locator.ResolveView(item, CompactContract);
+
+Console.WriteLine(standard?.GetType().Name);
+Console.WriteLine(detail?.GetType().Name);
+Console.WriteLine(compact?.IsCompact);
+```
+
+```text
+TodoItemPreviewView
+TodoItemDetailView
+True
+```
+
+## Register mappings at startup
+
+A shared locator needs its mappings before the first `ResolveView`. Do that in the builder. `ConfigureViewLocator`
+creates a `DefaultViewLocator`, hands you its `ViewMappingBuilder` and registers the locator. Call it after
+`WithCoreServices`, so the locator you configured is the one registered last. The next snippet maps two views in
+the builder and reads them back from the shared locator.
+
+```csharp
+var item = CreateItem();
+var builder = (IReactiveUIBindingBuilder)RxBindingBuilder.CreateReactiveUIBindingBuilder();
+
+_ = builder
+    .WithCoreServices()
+    .ConfigureViewLocator(static mappings => mappings
+        .Map<TodoItem, TodoItemPreviewView>()
+        .Map<TodoItem, TodoItemDetailView>(DetailContract))
+    .BuildApp();
+
+var locator = ViewLocator.GetCurrent();
+
+var standard = locator.ResolveView(item);
+var detail = locator.ResolveView(item, DetailContract);
+
+Console.WriteLine(standard?.GetType().Name);
+Console.WriteLine(detail?.GetType().Name);
+```
+
+```text
+TodoItemPreviewView
+TodoItemDetailView
+```
+
+The same call exists as an extension on Splat's `IAppBuilder`, so a chain that has passed through the Splat builder
+can still reach it. The extension lives in `ReactiveUI.Binding.Mixins`. It throws `InvalidOperationException` when
+the builder is not a ReactiveUI.Binding builder.
+
+```csharp
+var item = CreateItem();
+
+_ = RxBindingBuilder.CreateReactiveUIBindingBuilder()
+    .WithCoreServices()
+    .ConfigureViewLocator(static mappings => mappings.Map<TodoItem, TodoItemPreviewView>())
+    .BuildApp();
+
+var view = ViewLocator.GetCurrent().ResolveView(item);
+
+Console.WriteLine(view?.GetType().Name);
+```
+
+```text
+TodoItemPreviewView
+```
+
+The generated lookup is shared by every locator, so a locator built by `ConfigureViewLocator` still answers for the
+views the generator found.
+
+## The order the locator checks
+
+`DefaultViewLocator.ResolveView` checks three sources and returns the first view it finds.
+
+1. The generated lookup, the most recently registered assembly first.
+2. The mappings you added with `Map`.
+3. The service locator.
+
+Every source sets the view model on the view before the locator returns it. The example registers one view in
+each source and removes the mapping to show the next source answer.
+
+```csharp
+var item = CreateItem();
+var account = CreateAccount();
+DefaultViewLocator locator = new();
+locator.Map<Account, AccountStatementView>();
+locator.Map<TodoItem, TodoItemPreviewView>();
+AppLocator.CurrentMutable.Register<IViewFor<TodoItem>>(static () => new TodoItemDetailView());
+
+try
+{
+    var generated = locator.ResolveView(account);
+    var mapped = locator.ResolveView(item);
+    _ = locator.Unmap<TodoItem>();
+    var registered = locator.ResolveView(item);
+
+    Console.WriteLine(generated?.GetType().Name);
+    Console.WriteLine(mapped?.GetType().Name);
+    Console.WriteLine(registered?.GetType().Name);
+}
+finally
+{
+    AppLocator.CurrentMutable.UnregisterAll<IViewFor<TodoItem>>();
+}
+```
+
+```text
+AccountSummaryView
+TodoItemPreviewView
+TodoItemDetailView
+```
+
+The generated lookup answers for the account, even though the example mapped `AccountStatementView` for
+`Account`. The generated source comes first, so a mapping cannot override a view the generator registered.
+To replace a generated view, add `[ExcludeFromViewRegistration]` to it.
+
+## Next steps
+
+- [Setup](setup.md) shows the builder that registers the locator.
+- [Bindings](bindings.md) covers the view-first binding methods used above.
+- [Threading](threading.md) explains where a binding writes to a view.
+- [API reference](api.md) lists every member.
+
+## API reference
+
+| Member | What it does | Type and values | Notes |
+| --- | --- | --- | --- |
+| [`IViewFor`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IViewFor.cs) | Marks a class as a view of one view model, held as an `object`. | Interface. Extends `IActivatableView`. | Use it when the host does not know the view model type. |
+| [`IViewFor.ViewModel`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IViewFor.cs) | Gets or sets the view model the view shows. | Read and write [`object?`](https://learn.microsoft.com/dotnet/api/system.object). | A view implements it explicitly and forwards it to the typed property. |
+| [`IViewFor<T>`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IViewFor%7BT%7D.cs) | Marks a class as a view of one view model type. | Interface. `T : class`. Extends `IViewFor`. | The generator reads each class that implements it to build the view dispatch. |
+| [`IViewFor<T>.ViewModel`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IViewFor%7BT%7D.cs) | Gets or sets the view model the view shows, typed. | Read and write `T?`. | Hides the `object` property of `IViewFor`. The value is `null` until a host assigns one. |
+| [`IActivatableView`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IActivatableView.cs) | Marks an object as a view a host may activate. | Marker interface with no members. | Every `IViewFor` implements it. |
+| [`IViewLocator`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IViewLocator.cs) | Finds the view for a view model. | Interface. | Implement it to write your own locator. |
+| [`IViewLocator.ResolveView`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/IViewLocator.cs) | Returns the view for a view model under a contract. | Generic form `ResolveView<TViewModel>(TViewModel, string?)` with `TViewModel : class`, and `ResolveView(object?, string?)`. Both return `IViewFor?`. | A `null` contract picks the default screen. The result is `null` when no view matches. The `object` form carries `[RequiresDynamicCode]`. |
+| [`ViewLocatorMixins.ResolveView`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Interfaces/ViewLocatorMixins.cs) | Resolves a view with the default contract. | Extension of `IViewLocator`, in a generic form and an `object?` form. Both return `IViewFor?`. | Throws `ArgumentNullException` when the locator is `null`. The `object?` form carries `[RequiresDynamicCode]`. |
+| [`ViewLocator.GetCurrent`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/ViewLocator.cs) | Returns the locator registered with the service locator. | Static method on the static class `ViewLocator`. Returns `IViewLocator`. | Throws `ViewLocatorNotFoundException` when no locator is registered. |
+| [`ViewLocatorNotFoundException`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/ViewLocatorNotFoundException.cs) | Reports that no view locator is registered, or that a screen is missing. | Class that extends [`Exception`](https://learn.microsoft.com/dotnet/api/system.exception). | `ViewLocator.GetCurrent` throws it. Your own code can throw it. |
+| [`ViewLocatorNotFoundException(...)`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/ViewLocatorNotFoundException.cs) | Creates the exception. | No arguments, `string message`, or `string message` with `Exception innerException`. | The form with no arguments has a message that names `WithCoreServices` and `BuildApp`. |
+| [`DefaultViewLocator`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/DefaultViewLocator.cs) | The locator that `WithCoreServices` registers. | Sealed class. Implements `IViewLocator`. Has a public parameterless constructor. | Checks the generated lookup, then the mappings of the instance, then the service locator. |
+| [`DefaultViewLocator.ResolveView`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/DefaultViewLocator.cs) | Returns the view for a view model and sets its `ViewModel`. | The two forms of `IViewLocator.ResolveView`. | A `null` view model gives `null`. The generic form reads the compile-time type and the `object` form reads the runtime type. An exception from a view constructor or factory reaches the caller. |
+| [`DefaultViewLocator.Map`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/DefaultViewLocator.cs) | Registers a view for a view model type on this locator. | `Map<TViewModel, TView>()`, with `TView : IViewFor, new()`, or `Map<TViewModel>(Func<IViewFor> factory)`. Each takes an optional `string? contract`. `TViewModel : class`. Returns `void`. | Replaces a mapping for the same type and contract. A `null` contract is the default mapping. A `null` factory throws `ArgumentNullException`. |
+| [`DefaultViewLocator.Unmap`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/DefaultViewLocator.cs) | Removes a mapping. | `Unmap<TViewModel>()` or `Unmap<TViewModel>(string? contract)`. `TViewModel : class`. Returns [`bool`](https://learn.microsoft.com/dotnet/api/system.boolean). | `true` when a mapping existed. A `null` contract removes the default mapping. |
+| [`DefaultViewLocator.CreateMappingBuilder`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/DefaultViewLocator.cs) | Creates a builder that registers mappings in a chain. | Returns `ViewMappingBuilder`. | The builder writes to this locator. |
+| [`DefaultViewLocator.SetGeneratedViewDispatch`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/DefaultViewLocator.cs) | Adds a lookup that the locators check before mappings. | Static. Takes `Func<object, string, IViewFor?>`. | Generated code calls it. Editors hide it. The most recent lookup is asked first. A `null` argument throws `ArgumentNullException`. Adding a function twice has no effect. |
+| [`ViewMappingBuilder`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/ViewMappingBuilder.cs) | Registers mappings on a locator in a chain. | Sealed class. | Only `DefaultViewLocator.CreateMappingBuilder` and `ConfigureViewLocator` create one. |
+| [`ViewMappingBuilder.Map`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/ViewMappingBuilder.cs) | Registers a view for a view model type. | The same forms as `DefaultViewLocator.Map`. Returns `ViewMappingBuilder`. | Returns the builder so calls chain. A `null` factory throws `ArgumentNullException`. |
+| [`ViewContractAttribute`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/ViewContractAttribute.cs) | Registers a view in the generated lookup under a contract. | Sealed attribute for classes. Constructor takes `string contract`. | A view with no attribute is the default screen for its view model. |
+| [`ViewContractAttribute.Contract`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/ViewContractAttribute.cs) | Gets the contract string. | Read-only [`string`](https://learn.microsoft.com/dotnet/api/system.string). | The string a caller passes to `ResolveView`. |
+| [`SingleInstanceViewAttribute`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/SingleInstanceViewAttribute.cs) | Makes the generated lookup build the view once and reuse it. | Sealed attribute for classes. | Needs a parameterless constructor. Do not use it on a view shown in more than one place at once. |
+| [`ExcludeFromViewRegistrationAttribute`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/View/ExcludeFromViewRegistrationAttribute.cs) | Leaves a view out of the generated lookup. | Sealed attribute for classes. Not inherited. One per class. | Register the view with `Map` or the service locator instead. |
+| [`ConfigureViewLocator`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Builder/ReactiveUIBindingBuilder.cs) | Registers a `DefaultViewLocator` that holds the mappings you add. | Takes `Action<ViewMappingBuilder> configure`. Returns `IReactiveUIBindingBuilder`. | A `null` action throws `ArgumentNullException`. An extension on `IAppBuilder` in [`BuilderMixins`](https://github.com/reactiveui/ReactiveUI.Binding.SourceGenerators/blob/main/src/ReactiveUI.Binding.Shared/Mixins/BuilderMixins.cs) throws `InvalidOperationException` for another builder type. |
diff --git a/docs/documentation/getting-started/compelling-example.md b/docs/documentation/getting-started/compelling-example.md
index 1481e613..843d8850 100644
--- a/docs/documentation/getting-started/compelling-example.md
+++ b/docs/documentation/getting-started/compelling-example.md
@@ -140,7 +140,7 @@ The goal of the ReactiveUI syntax for read-write properties is to notify Observe
 
 In cases when we don't need to provide for two-way binding between the View and the ViewModel, we can use one of many ReactiveUI Helpers, to notify Observers of a changing read-only value in the ViewModel. We use the [ObservableAsPropertyHelper](../handbook/observable-as-property-helper.md) twice, once to turn a generic IEnumerable<T> into an observable read-only collection, and then to change the visibility of an indicator to show that a request is currently executing.
 
-This also works in the opposite direction, when we take the `SearchTerm` property and [turn it into an observable](../handbook/when-any.md). This means that we are notified every time a change occurs in the UI. Using [ReactiveUI.Primitives](../primitives/index.md), we then [calm](../primitives/time.md) those events, and ensure that the search occurs no sooner than 800ms after the last keystroke. And if at that point the user did not change the last value, or if the search term is blank, we ignore the event completely. We have another ObservableAsPropertyHelper property `IsAvailable` which is generated by determining if our current SearchResults is null.
+This also works in the opposite direction, when we take the `SearchTerm` property and [turn it into an observable](../binding/observing.md). This means that we are notified every time a change occurs in the UI. Using [ReactiveUI.Primitives](../primitives/index.md), we then [calm](../primitives/time.md) those events, and ensure that the search occurs no sooner than 800ms after the last keystroke. And if at that point the user did not change the last value, or if the search term is blank, we ignore the event completely. We have another ObservableAsPropertyHelper property `IsAvailable` which is generated by determining if our current SearchResults is null.
 
 Let's now create a `NugetDetailsViewModel.cs` class that will wrap our NuGet metadata into a more usable class for our View. It includes a [ReactiveCommand](../handbook/commands/index.md) for opening the NuGet Repository URL.
 
diff --git a/docs/documentation/getting-started/index.md b/docs/documentation/getting-started/index.md
index 2c6f8e16..c33813a8 100644
--- a/docs/documentation/getting-started/index.md
+++ b/docs/documentation/getting-started/index.md
@@ -35,7 +35,7 @@ ReactiveUI makes it easy to combine the MVVM pattern with Reactive Programming b
 
 - **[RxAppBuilder](../handbook/rxappbuilder.md)** - Modern application initialization and dependency injection
 - **[ReactiveUI.SourceGenerators](https://github.com/reactiveui/ReactiveUI.SourceGenerators)** - Compile-time code generation for reactive properties and commands
-- **[WhenAnyValue](../handbook/when-any.md)** - Observe property changes reactively
+- **[WhenAnyValue](../binding/observing.md)** - Observe property changes reactively
 - **[ReactiveCommand](../handbook/commands/index.md)** - Asynchronous, composable command execution
 - **[ObservableAsPropertyHelper](../handbook/observable-as-property-helper.md)** - Transform observables into read-only properties
 - **[WhenActivated](../handbook/when-activated.md)** - Manage subscriptions and prevent memory leaks
diff --git a/docs/documentation/handbook/commands/binding-commands.md b/docs/documentation/handbook/commands/binding-commands.md
deleted file mode 100644
index cc532218..00000000
--- a/docs/documentation/handbook/commands/binding-commands.md
+++ /dev/null
@@ -1,163 +0,0 @@
----
-Order: 2
----
-# Binding Commands
-
-View model commands that need to be bound to view controls must implement the `ICommand` interface. View model commands are typically bound to view controls using one of the `BindCommand` overloads available in the view. Let's see an example:
-
-```cs
-// In a view
-this.BindCommand(
-    this.ViewModel,
-    vm => vm.MyCommand,
-    v => v.myControl); 
-```
-
-Here we bind `myControl` in the view to `MyCommand` from the view model. What happens next depends on any `ICreatesCommandBinding` instances registered in the [service locator](https://reactiveui.net/docs/handbook/dependency-inversion/). Normally, `myControl` in the view will be disabled whenever the command cannot execute. If the control is enabled and the user interacts with it in the expected way, the command will execute. For example, if `myControl` is a button, the user would have to click or tap on it.
-
-> **Note:** The above example shows a naked call to `BindCommand`; however, `BindCommand` will often be called in a `WhenActivated` block:
-> 
-> ```cs
-> this.WhenActivated(
->     d =>
->     {
->         d(this.BindCommand(
->             this.ViewModel,
->             vm => vm.MyCommand,
->             v => v.myControl));
->     });
-> ```
-> 
-> See the [documentation](../when-activated.md) on `WhenActivated` for more information.
-
-The `BindCommand` call shown above doesn't provide any hint as to which event will trigger command execution. In this case, the default event for the control will be used, such as `Click` or `Tapped`. If the command should execute when a specific event is triggered, use an overload of `BindCommand` that takes an event name:
-
-```cs
-this.BindCommand(
-    this.ViewModel,
-    vm => vm.MyCommand,
-    v => v.myControl,
-    nameof(myControl.SomeEvent));
-```
-
-Here `myControl.SomeEvent` (and not the default event) will cause the command to execute.
-
-> **Note:** When this `BindCommand` overload is used in a `WhenActivated` block, it is important to dispose the binding when the view gets deactivated. `BindCommand` subscribes to the given event each time the view is activated. If the binding is not disposed, the subscription to the event will not be canceled. This will lead to multiple subscriptions to the same event, and the command will execute once for each of the event subscriptions whenever the event is triggered.
-
-Some `BindCommand` overloads also accept a parameter for the command. The parameter can be a function, an observable, or an expression that resolves to a property of the view model:
-
-```cs
-// use an observable as the source for command parameters
-IObservable<int> param = ...;
-this.BindCommand(
-    this.ViewModel,
-    vm => vm.MyCommand,
-    v => v.myControl,
-    param);
-
-// use a property on the VM as a command parameter
-this.BindCommand(
-    this.ViewModel,
-    vm => vm.MyCommand,
-    v => v.myControl,
-    vm => vm.SomeProperty);
-```
-
-|Platform Feature Description|WPF|Windows Forms|Android|iOS|WinUI|MAUI|
-|:--:|:--:|:--:|:--:|:--:|:--:|:--:|:--:|
-|CommandParameter binding|&#x2714;|-|-|-|&#x2714;|&#x2714;|
-
-<details><summary>Command Execution using CommandParameter binding</summary>
-
-CommandParameter binds automatically to `TInput` in `ReactiveCommand<TInput, RxVoid>`
-
-```xml
-//In the view
-<Button x:Name="FeedType"
-    Content="Live Feed"
-    CommandParameter="LiveFeed">
-</Button>
-```
-
-```cs
- //In the code-behind file
- this.WhenActivated(disposableRegistration =>
- {
-    this.BindCommand(ViewModel,
-    viewModel => viewModel.ProcessFeed,
-    view => view.FeedType)
-    .DisposeWith(disposableRegistration);
- });
-
- //In the ViewModel
- public class MyViewModel
- {
-    public ReactiveCommand<string, RxVoid> ProcessFeed { get; }
-   
-    public MyViewModel()
-    {
-        //Create a ReactiveCommand that accepts an input of type string.
-        ProcessFeed = ReactiveCommand.Create<string>(x => FeedProcessor(x));
-    }
-
-    private void FeedProcessor(string feedType)
-    {
-        //Here feedType will be "LiveFeed"
-    }
- }
- ```
-
-</details>
-
-<details><summary>Command Execution using ViewModel Properties</summary>
-
-```xml
-//In the view
-<Button x:Name="FeedType"
-    Content="Live Feed">
-</Button>
-```
-
-```cs
- //In the code-behind file
- this.WhenActivated(disposableRegistration =>
- {
-    this.BindCommand(ViewModel,
-    viewModel => viewModel.ProcessFeed,
-    view => view.FeedType)
-    .DisposeWith(disposableRegistration);
- });
-
- //In the ViewModel
- public class MyViewModel
- {
-    public ReactiveCommand<RxVoid, RxVoid> ProcessFeed { get; }
-
-    private string _feedType;
-    public string FeedType
-    {
-        get => _feedType;
-        set => this.RaiseAndSetIfChanged(ref _feedType, value);
-    }
-
-    public MyViewModel()
-    {
-        //Create a ReactiveCommand that accepts an input of type string.
-        ProcessFeed = ReactiveCommand.Create(FeedProcessor);
-    }
-
-    private void FeedProcessor()
-    {
-        var feedName = FeedType;
-         //Here FeedType will be the value assigned when the ViewModel was created
-    }
- }
- ```
-
-</details>
-
-
-`CommandParameter` can be a good choice when the view contains multiple buttons that cannot be generated using an `ItemTemplate`. 
-`CommandParameter` is a way to reuse a command without having to create additional properties on the ViewModel. Be aware that `CommandParameter` cannot be used to determine if a command can execute or not.
-
-However, if the buttons can be generated at runtime through `ItemTemplate`, it is highly recommended to use ViewModel properties for CommandExecution.
diff --git a/docs/documentation/handbook/commands/index.md b/docs/documentation/handbook/commands/index.md
index 1e595332..919443e4 100644
--- a/docs/documentation/handbook/commands/index.md
+++ b/docs/documentation/handbook/commands/index.md
@@ -103,7 +103,7 @@ LoadUsers.ThrownExceptions.Subscribe(exception =>
 
 ## Controlling executability
 
-A `ReactiveCommand` may or may not be executable in a given situation. For example, the command backing the *Save* menu item might be unavailable if there are no unsaved changes. We pass into the `ReactiveCommand` an `IObservable<bool>` of when the ReactiveCommand should be allowed to be executed. The `ReactiveCommand` uses an IObservable eventing system to determine if execution should be allowed which differs from other frameworks where you might have the command continuous poll if execution is allowed. The ReactiveCommand approach has some performance advantages in that the value is cached between the can execute observable being fired. You commonly will create your can execute observable using the [`WhenAnyValue` functions](../when-any.md) provided by the ReactiveUI framework: 
+A `ReactiveCommand` may or may not be executable in a given situation. For example, the command backing the *Save* menu item might be unavailable if there are no unsaved changes. We pass into the `ReactiveCommand` an `IObservable<bool>` of when the ReactiveCommand should be allowed to be executed. The `ReactiveCommand` uses an IObservable eventing system to determine if execution should be allowed which differs from other frameworks where you might have the command continuous poll if execution is allowed. The ReactiveCommand approach has some performance advantages in that the value is cached between the can execute observable being fired. You commonly will create your can execute observable using the [`WhenAnyValue` functions](../../binding/observing.md) provided by the ReactiveUI framework: 
 
 ```cs
 // Each time values of UserName and Password properties change,
@@ -278,7 +278,7 @@ command.Execute().Subscribe();
 
 ## Bindings
 
-`ReactiveCommand` can be connected to the View by either using XAML binding on supported platforms, or using the inbuilt [ReactiveUI binding](../data-binding/index.md) method `BindCommand`. Use of BindCommand is preferred but not required where XAML bindings are supported. Read more on this [here](binding-commands.md).
+`ReactiveCommand` can be connected to the View by either using XAML binding on supported platforms, or using the inbuilt [ReactiveUI binding](../data-binding/index.md) method `BindCommand`. Use of BindCommand is preferred but not required where XAML bindings are supported. Read more on this [here](../../binding/bindings.md).
 
 ## Unit Testing
 
diff --git a/docs/documentation/handbook/data-binding/index.md b/docs/documentation/handbook/data-binding/index.md
index 16a54245..e59ef10f 100644
--- a/docs/documentation/handbook/data-binding/index.md
+++ b/docs/documentation/handbook/data-binding/index.md
@@ -3,33 +3,18 @@ Order: 5
 ---
 # Data Binding in ReactiveUI
 
-A core part of being able to use the MVVM pattern is the very specific relationship between the ViewModel and View - that is, the View is connected in a one-way dependent manner to the ViewModel via *bindings*. ReactiveUI provides its own implementation of this concept, which has a number of advantages compared to platform-specific implementations such as XAML-based bindings.
+A binding connects a property on a view model to a property on a view. When one side changes, the binding writes the new value to the other side. ReactiveUI bindings are written with lambda expressions, so a renamed property breaks the build instead of failing at run time.
 
-* Bindings work on **all platforms** and operate the same.
-* Bindings are written via Expressions. This means that they are strongly typed, and renaming a ViewModel property, or a control in the UI layout without updating the binding, the build will fail.
-* Controlling how types bind to properties is flexible and can be customized.
+[ReactiveUI.Binding](../../binding/index.md) is the binding engine. A source generator reads each binding at build time and writes the code for it, so bindings need no reflection and work with trimming and Native AOT. The Binding section covers:
 
-## Getting Started
+* [Observing property changes](../../binding/observing.md) with `WhenChanged`, `WhenAnyValue` and the other observation methods.
+* [Bindings](../../binding/bindings.md) with `BindOneWay`, `BindTwoWay`, `BindTo`, `BindCommand` and `BindInteraction`.
+* [Converters](../../binding/converters.md) and [custom converters](../../binding/custom-converters.md) for values whose types differ.
+* [Notification mechanisms](../../binding/mechanisms.md), [views](../../binding/views.md), [threading](../../binding/threading.md) and [setup](../../binding/setup.md).
 
-In order to use bindings in the View, you must first implement `IViewFor<TViewModel>` on your View. Depending on the platform, you must implement it differently:
+## Platforms
 
-* **iOS** - change your base class to one of the Reactive UIKit classes (i.e.
-  `ReactiveViewController`) and implement `ViewModel` using
-  `RaiseAndSetIfChanged`, *or* implement `INotifyPropertyChanged` on your View and
-  ensure that ViewModel signals changes.
-
-* **Android:** - change your base class to one of the Reactive Activity /
-  Fragment classes (i.e. `ReactiveActivity<T>`), *or* implement
-  `IViewFor<T>` on your View and ensure that your ViewModel signals
-  changes.
-
-* **Xaml-based:** - Implement `IViewFor<T>` by hand and ensure that ViewModel
-  is a `DependencyProperty`. Additionally, for `UserControl`s you can use a base 
-  class that encapsulates `IViewFor` behavior - `ReactiveUserControl<TViewModel>`.
-  
-### Platforms
-
-For a detailed overview of the bindings on each platform, see the following sections:
+The platform pages below cover the view base classes and activation for each UI framework. Each one builds on [WhenActivated](../when-activated.md) and the platform base classes.
 
 * [Android](android/index.md)
 
@@ -39,164 +24,16 @@ For a detailed overview of the bindings on each platform, see the following sect
 
 * [Windows Presentation Foundation](windows-presentation-foundation.md)
 
-* [Windows Forms](windows-forms.md)
+* [Windows Forms](../../binding/threading.md)
 
 * [Avalonia UI](avalonia.md)
 
-## Types of Bindings
-
-Once you implement `IViewFor<T>`, binding methods are now available as extension methods on your class, as well as [activation and deactivation](../when-activated.md) feature for your views and associated view models. Like many other things in ReactiveUI, you should only set up bindings in a constructor or even better in a [WhenActivated](../when-activated.md) block.
-
-`OneWayBind`, `Bind`, `BindCommand` and `Subscribe` methods return an `IDisposable`. In general, you shouldn't care about this return value, except if you want to break a binding manually, or you're on a XAML-based platform, where bindings can leak memory. [WhenActivated](../when-activated.md) feature helps handle this concern gracefully.
-
-* **OneWayBind:** - Sets up a one-way binding from a property on the ViewModel
-  to the View.
-
-```csharp
-this.OneWayBind(ViewModel,
-    viewModel => viewModel.Name,
-    view => view.Name.Text);
-
-// OR
-
-this.WhenAnyValue(x => x.ViewModel.Name)
-    .BindTo(this, view => view.Name.Text);
-```
-
-* **Bind:** - Sets up a two-way binding between a property on the ViewModel to
-  the View.
-
-```csharp
-this.Bind(ViewModel, 
-    viewModel => viewModel.Name, 
-    view => view.Name.Text);
-```
-
-* **BindCommand:** - Bind an `ICommand` to a control, or to a specific event on that control (how this is implemented depends on the UI framework):
-
-```csharp
-// Bind the OK command to the button.
-// This uses the default "Click" event on XAML-based platforms
-// and equivalent events on Android and iOS.
-this.BindCommand(ViewModel,
-    viewModel => viewModel.OkCommand,
-    view => view.OkButton);
-
-// Bind the OK command to when the user presses a key
-this.BindCommand(ViewModel,
-    viewModel => viewModel.OkCommand,
-    view => view.RootView,
-    "KeyUp");
-```
-
-## Converting between types
-
-Direct bindings between properties are convenient, but often the two types are not assignable to each other. For example, binding an "Age" property to a TextBox would normally fail, because the TextBox expects a string value. Instead, ReactiveUI has an extensible system for coercing between types.
-
-For simple one-way bindings, you can use the conversion parameter in the `OneWayBind` method. This parameter is a `Func<TIn, TOut>`, so if the ViewModel property is of type `int` and the view property is of type `string`, it's a `Func<int, string>`
-which means that you don't have to write custom converter classes, like in standard WPF bindings, and can just write a simple, statically typed, conversion function.
-
-```csharp
-// Note: Age is an integer, Text is a string
-this.OneWayBind(ViewModel, 
-    viewModel => viewModel.Age, 
-    view => view.Name.Text, 
-    value => value.ToString()); // In the last parameter, we .ToString() the integer
-```
-
-### Creating custom Value Converters classes
-
-You can also register converters globally and convert types for two-way bindings. See [Value Converters](value-converters.md) page for details.
-
-## Choosing when to update the source
-
-By default, the source of a binding will be updated when the target changes, which is equivalent to setting `UpdateSourceTrigger = PropertyChanged` on a WPF binding. Sometimes it is desirable to have more fine-grained control over when the source will be updated (for example, the binding updating will trigger some expensive work which isn't necessary on every keystroke).
-
-One common requirement is to update the source when a user interface control loses keyboard (or logical) focus - WPF even provides `UpdateSourceTrigger = LostFocus` for this.
-
-ReactiveUI bindings allow this by providing an `IObservable` as a parameter to the binding, which disables the default behavior and causes the source to update whenever the observable fires. The parameter (`SignalViewUpdate`) can be of any `IObservable<object>`, meaning that any event on a user interface control is capable of causing the binding to update.
-
-For example, to have a binding update when a control loses keyboard focus, the following binding setup can be used:
-
-```cs
-// Note: We're using the ReactiveUI.Events NuGet package here, which 
-// wraps traditional .NET events on UI controls into IObservables and 
-// exposes them via the Events() extension method.
-this.Bind(ViewModel, 
-    viewModel => viewModel.SomeProperty, 
-    view => view.SomeTextBox, 
-    SomeTextBox.Events().LostKeyboardFocus);
-```
-
-## Why not use Subscribe?
-
-This is a good question, as both `BindTo` and `Subscribe` provide similar functionality; both can be used to bind your view to viewModel properties. Take the following two examples, both result in the same outcome, just with different styles:
-
-```cs
-//1. Using BindTo
-ViewModel.Name
-         .Select(x => $"Label: {x}")
-         .BindTo(this, x => x.loginButton.Text)
-         .DisposeWith(disp);
-```
-
-```cs
-//2. Using Subscribe
-ViewModel.Name
-         .Select(x => $"Label: {x}")
-         .Subscribe(x => loginButton.Text = x)
-         .DisposeWith(disp);
-```
-
-Although both are similar, `BindTo` does offer a number of benefits:
-
-* Can handle globally registered converters - See the [Value Converters](value-converters.md) page for details
-* Can handle special semantics within the ReactiveUI binding engine - e.g. on WinForms there are a number of properties where the set methods are automatically called
-* Provides a consistent style across multiple projects (iOS/Android...)
-
-In general `BindTo` is the recommended approach to binding. However as with a lot of ReactiveUI, you are free to choose the style which suits you best.
-
-## "Hack" bindings and BindTo
-
-Should you find that direct one and two-way bindings aren't enough to get the job done (or should you want View => ViewModel bindings), a flexible, Rx-based approach is also available, via combining `WhenAnyValue` with the `BindTo` operator, which allows you to one-way-bind an arbitrary `IObservable` to a property on an object.
-
-For example, here is a simple example of binding a ListBox's `SelectedItem` to a ViewModel:
-
-```cs
-public MainView()
-{
-    // Bind the View's SelectedItem to the ViewModel
-    this.WhenAnyValue(x => x.SomeList.SelectedItem)
-        .BindTo(this, x => x.ViewModel.SelectedItem);
-
-    // Bind ViewModel's IsSelected via SelectedItem. Note that this
-    // is only for illustrative purposes, it'd be better to bind this
-    // at the ViewModel layer (i.e. WhenAnyValue + ToProperty)
-    this.WhenAnyValue(x => x.SomeList.SelectedItem)
-        .Select(x => x != null)
-        .BindTo(this, x => x.ViewModel.IsSelected);
-}
-```
-
-`BindTo` applies the same binding hooks and type conversion that other property binding methods do, so the types don't necessarily have to match between the source and the target property.
-
-While you could certainly build complex bindings (even ones between two view models!), keep in mind that binding logic that you put in the View is untestable, so keeping the meaningful logic out of bindings is usually a Good Idea.
-
-## "Hack" Command Bindings
+## Implement IViewFor on the view
 
-Similarly to property bindings, you can also add custom Hack bindings for commands as well. Two methods that are useful for this are `InvokeCommand` and `WhenAnyObservable`. The former allows you to invoke a command whenever an Observable signals, and the latter allows you to safely get an Observable from a ViewModel in a safe way. Here's how they apply to commands:
+A view needs an `IViewFor<TViewModel>` implementation before it can use the view-first binding methods. The way to implement it depends on the platform.
 
-```cs
-//
-// This code is all in the View constructor
-//
+* **iOS:** change the base class to one of the Reactive UIKit classes, such as `ReactiveViewController`, and implement `ViewModel` with `RaiseAndSetIfChanged`. You can also implement `INotifyPropertyChanged` on the view and make sure the `ViewModel` property signals changes.
 
-// Invoke a command whenever the Escape key is pressed
-this.Events().KeyUp
-    .Where(x => x.Key == Key.Escape)
-    .InvokeCommand(this, x => x.ViewModel.Cancel);
+* **Android:** change the base class to one of the Reactive Activity or Fragment classes, such as `ReactiveActivity<T>`. You can also implement `IViewFor<T>` on the view and make sure the `ViewModel` property signals changes.
 
-// Subscribe to Cancel, and close the Window when it happens
-this.WhenAnyObservable(x => x.ViewModel.Cancel)
-    .Subscribe(_ => this.Close());
-```
+* **XAML-based platforms:** implement `IViewFor<T>` by hand and make `ViewModel` a `DependencyProperty`. A `UserControl` can use the `ReactiveUserControl<TViewModel>` base class instead.
diff --git a/docs/documentation/handbook/data-binding/value-converters.md b/docs/documentation/handbook/data-binding/value-converters.md
deleted file mode 100644
index 092b6e79..00000000
--- a/docs/documentation/handbook/data-binding/value-converters.md
+++ /dev/null
@@ -1,94 +0,0 @@
----
-Order: 2
----
-# Value Converters
-
-A value converter should implement the `IBindingTypeConverter` interface. See an example of a globally registered converter type that converts between Boolean and XAML Visibility: [BooleanToVisibilityTypeConverter.cs](https://github.com/reactiveui/ReactiveUI/blob/main/src/ReactiveUI.Wpf/Common/BooleanToVisibilityTypeConverter.cs)
-
-## How GetAffinityForObjects works
-
-Return 0 if you can't convert an object and return anything else if it is possible. The largest value wins. 
-
-```csharp
-public int GetAffinityForObjects(Type fromType, Type toType)
-{
-    if (fromType == typeof(string))
-    {
-        return 100; // any number other than 0 signifies conversion is possible.
-    }
-    return 0;
-}
-```
-
-## How TryConvert works
-
-TryConvert function takes four arguments. The first one is value we are trying to convert, the second one is type to which we are trying to convert that value. `conversionHint` is like a converter parameter, and `result` is where we need to store the conversion result. TryConvert function should return `true` if conversion succeeds and `false` if conversion fails.
-
-```csharp
-public bool TryConvert(object from, Type toType, object conversionHint, out object result)
-{
-    try
-    {
-        result = !string.IsNullOrWhiteSpace((string)from);
-    }
-    catch (Exception ex)
-    {
-        this.Log().WarnException("Couldn't convert object to type: " + toType, ex);
-        result = null;
-        return false;
-    }
-
-    return true;
-}
-```
-
-## Registration
-
-If you'd like to use a custom converter globally, you need to register it using Splat Locator.
-
-```csharp
-AppLocator.CurrentMutable.RegisterConstant(
-    new MyCoolTypeConverter(), 
-    typeof(IBindingTypeConverter)
-);
-```
-
-## Usage
-
-For globally registered converters, usage is **automatic**. When a binding is created, the converter(s) with the highest affinity are chosen from those registered with Splat. Optionally, you can provide a specific converter to override what the default would have been for either VM to View or View to VM. In this case you don't need to register a converter:
-
-```csharp
-this.Bind(ViewModel, 
-    viewModel => viewModel.ViewModelProperty, 
-    view => view.Control.Property,
-    vmToViewConverterOverride: new CustomTypeConverter());
-```
-
-It's important to specify `vmToViewConverterOverride` to be sure not to accidentally pass your converter to the `conversionHint` parameter.
-    
-## Inline Binding Converters
-
-You can supply inline function methods to Bind. This allows you to quickly supply a conversion method. This avoids having to supply a IBindingTypeConverter for one off cases. 
-
-```csharp            
-this.WhenActivated(disposables =>
-{
-    this.Bind(this.ViewModel, 
-        viewModel => viewModel.DateTime, 
-        view => view.DateTextBox.Text, 
-        this.ViewModelToViewConverterFunc, 
-        this.ViewToViewModelConverterFunc)
-        .DisposeWith(disposables);
-});
-                    
-private string ViewModelToViewConverterFunc(DateTime dateTime)
-{
-    return dateTime.ToString("O"); // return ISO 8601 Date ime
-}
-
-private DateTime ViewToViewModelConverterFunc(string value)
-{
-    DateTime.TryParse(value, out DateTime returnValue);
-    return returnValue;
-}            
-```
diff --git a/docs/documentation/handbook/data-binding/windows-forms.md b/docs/documentation/handbook/data-binding/windows-forms.md
deleted file mode 100644
index f884e1a4..00000000
--- a/docs/documentation/handbook/data-binding/windows-forms.md
+++ /dev/null
@@ -1,6 +0,0 @@
----
-Order: 4
----
-# Data Binding in Windows Forms with ReactiveUI
-
-See [Using ReactiveUI for WinForms MVVM Design](https://www.codeproject.com/Articles/801986/Using-ReactiveUI-for-WinForms-MVVM-Design)
diff --git a/docs/documentation/handbook/interactions/binding-interactions.md b/docs/documentation/handbook/interactions/binding-interactions.md
deleted file mode 100644
index ab8701d9..00000000
--- a/docs/documentation/handbook/interactions/binding-interactions.md
+++ /dev/null
@@ -1,59 +0,0 @@
----
-Order: 2
----
-# Binding Interactions
-
-In addition to registering `Interaction` handlers manually, we also provide a set of view extension methods for setting up bindings, both of which mimic the `handler` parameter of the `RegisterHandler` overloads:
-
-```cs
-IDisposable BindInteraction<TViewModel, TView, TInput, TOutput>(
-    this TView view,
-    TViewModel? viewModel,
-    Expression<Func<TViewModel, IInteraction<TInput, TOutput>>> propertyName,
-    Func<IInteractionContext<TInput, TOutput>, Task> handler);
-
-IDisposable BindInteraction<TViewModel, TView, TInput, TOutput, TDontCare>(
-    this TView view,
-    TViewModel? viewModel,
-    Expression<Func<TViewModel, IInteraction<TInput, TOutput>>> propertyName,
-    Func<IInteractionContext<TInput, TOutput>, IObservable<TDontCare>> handler);
-```
-
-Registering handlers manually is fine for simple scenarios. But if, for example, you expect your `Interaction` or one of its ancestors to change, the complexity starts increasing because of the need to dispose of the old and subscribe to the latest:
-
-```cs
-var interactionDisposable = new SingleReplaceableDisposable();
-
-this
-    .WhenAnyValue(x => x.ViewModel.MyInteraction)
-    .Where(x => x != null)
-    .Tap(x => interactionDisposable.Create(x.RegisterHandler(context => /*Do Something*/)))
-    .Finally(() => interactionDisposable?.Dispose())
-    .Subscribe();
-```
-
-Compare that with the binding approach...
-
-```cs
-// In a view
-this.BindInteraction(
-    this.ViewModel,
-    vm => vm.MyInteraction,
-    context => /*Do Something*/);
-```
-
-and it's clear to see the benefits.
-
-Just like the rest of the `Bind` family, it's easy to "unhook" the binding by disposing of the returned `IDisposable` object. If you're using the `WhenActivated` feature, it's simply:
-
-```cs
-this.WhenActivated(
-    disposables =>
-    {
-        this.BindInteraction(
-                this.ViewModel,
-                vm => vm.MyInteraction,
-                context => /*Do Something*/)
-            .DisposeWith(disposables);
-    });
-```
diff --git a/docs/documentation/handbook/user-input-validation.md b/docs/documentation/handbook/user-input-validation.md
index 17fb88a1..3576e598 100644
--- a/docs/documentation/handbook/user-input-validation.md
+++ b/docs/documentation/handbook/user-input-validation.md
@@ -5,7 +5,7 @@ Order: 20
 
 When building applications, you often need to validate user input. This is especially true for mobile applications, where users expect immediate feedback on their actions. In this guide, we will explore how to implement user input validation in ReactiveUI applications using built-in features and the ReactiveUI.Validation package.
 
-ReactiveUI itself offers a few powerful features allowing you to validate user input on fly. With [WhenAnyValue](when-any.md), you can listen to view model property changes and control [ReactiveCommand](commands/index.md) executability. When reactive command's `CanExecute` observable returns false, the control to which you bind that command stays disabled. The simplest validator looks as follows:
+ReactiveUI itself offers a few powerful features allowing you to validate user input on fly. With [WhenAnyValue](../binding/observing.md), you can listen to view model property changes and control [ReactiveCommand](commands/index.md) executability. When reactive command's `CanExecute` observable returns false, the control to which you bind that command stays disabled. The simplest validator looks as follows:
 
 ```cs
 // Declare name validator as IObservable<bool> which emitts a new value when name changes.
diff --git a/docs/documentation/handbook/view-models/index.md b/docs/documentation/handbook/view-models/index.md
index c30d10d2..029d4166 100644
--- a/docs/documentation/handbook/view-models/index.md
+++ b/docs/documentation/handbook/view-models/index.md
@@ -26,7 +26,7 @@ Many people believe that the MVVM pattern means that there should be zero code i
 
 So then, how do I decide what to put in the View? Concepts such as scroll position and control focus are great examples of code that is View-specific. Handling animation and Window position / minimize are also great examples of code that often should be in the View.
 
-Another common misconception is that of separation - while it is very important that the ViewModel have no reference to the View or any of the controls that the View creates, **the reverse is not true**. The View is free to be very tightly bound to the ViewModel, and in fact, it is often useful for the View to "reach into" the ViewModel via [WhenAny, WhenAnyValue and WhenAnyObservable](../when-any.md).
+Another common misconception is that of separation - while it is very important that the ViewModel have no reference to the View or any of the controls that the View creates, **the reverse is not true**. The View is free to be very tightly bound to the ViewModel, and in fact, it is often useful for the View to "reach into" the ViewModel via [WhenAny, WhenAnyValue and WhenAnyObservable](../../binding/observing.md).
 
 With the theory out of the way, let's see how to create ViewModels in ReactiveUI.
 
@@ -51,7 +51,7 @@ public string Name
 }
 ```
 
-Note, that unlike in other frameworks, they are **always written this way**, using the exact same boilerplate code. If you are attempting to put *anything* in the setter, you are almost certainly Doing It Wrong, and should be using [WhenAnyValue](../when-any.md) and [ToProperty](../observable-as-property-helper.md) instead. 
+Note, that unlike in other frameworks, they are **always written this way**, using the exact same boilerplate code. If you are attempting to put *anything* in the setter, you are almost certainly Doing It Wrong, and should be using [WhenAnyValue](../../binding/observing.md) and [ToProperty](../observable-as-property-helper.md) instead. 
 
 ## Read-Only Properties
 
@@ -72,7 +72,7 @@ public PostViewModel()
 
 So far, nothing here has been particularly surprising, just boilerplate MVVM features. However, there is another type of Property in ReactiveUI that doesn't exist in other frameworks that is **very important** to effectively use ReactiveUI, the "Output Property".
 
-Output properties are a way to take *Observables* and convert them into *ViewModel Properties*. We'll often use them with the opposite method, which turns ViewModel Properties into Observables, [WhenAnyValue](../when-any.md). As the name implies, Output Properties are usually read-only (i.e. the source Observable dictates when the property changes).
+Output properties are a way to take *Observables* and convert them into *ViewModel Properties*. We'll often use them with the opposite method, which turns ViewModel Properties into Observables, [WhenAnyValue](../../binding/observing.md). As the name implies, Output Properties are usually read-only (i.e. the source Observable dictates when the property changes).
 
 First, we need to be able to declare an Output Property, using a class called `ObservableAsPropertyHelper<T>`:
 
@@ -94,7 +94,7 @@ Here, `ToProperty` creates an `ObservableAsPropertyHelper` instance which will s
 
 ## Best Practices
 
-One of the core concepts of Functional Reactive Programming, is that instead of writing *imperative code* (i.e. "Do A right now, then do B, then do C"), we want to write *Functional, Declarative code* - instead of writing event handlers and methods to change properties, we want **to Describe how properties are related to each other**, using [WhenAnyValue](../when-any.md) and [ToProperty](../observable-as-property-helper.md).
+One of the core concepts of Functional Reactive Programming, is that instead of writing *imperative code* (i.e. "Do A right now, then do B, then do C"), we want to write *Functional, Declarative code* - instead of writing event handlers and methods to change properties, we want **to Describe how properties are related to each other**, using [WhenAnyValue](../../binding/observing.md) and [ToProperty](../observable-as-property-helper.md).
 
 As a result, almost all of the interesting code in a well-written ReactiveUI ViewModel will be in the *constructor*; this code will describe how the properties in the ViewModel are related to each other. Your goal when writing the code for a ViewModel, is to take statements that describe how the view *should* work in terms of its commands and properties, and to translate them into things to put into the constructor. For example:
 
diff --git a/docs/documentation/handbook/when-activated.md b/docs/documentation/handbook/when-activated.md
index d111afce..57825e29 100644
--- a/docs/documentation/handbook/when-activated.md
+++ b/docs/documentation/handbook/when-activated.md
@@ -100,7 +100,7 @@ As a rule of thumb for all platforms, you should use it for bindings and any tim
 
 ## When should I bother disposing of IDisposable objects?
 
-If you do a [WhenAny](when-any.md) on anything other than `this`, you **need** to put it inside a `WhenActivated` block and add a call to `DisposeWith`. If you just launch a window and then that window goes away when app goes away and you have nothing else to manage, you don't need `WhenActivated`. 
+If you do a [WhenAny](../binding/observing.md) on anything other than `this`, you **need** to put it inside a `WhenActivated` block and add a call to `DisposeWith`. If you just launch a window and then that window goes away when app goes away and you have nothing else to manage, you don't need `WhenActivated`. 
 
 Always use `WhenActivated` and `DisposeWith` with XAML views, if you're writing `this.WhenAnyValue(x => x.ViewModel.Prop).BindTo(...)` or `this.Bind*(...)` (read more on bindings [here](data-binding/index.md)). You should use it any time there's something your view sets up that will outlive the view - on a Xaml platform, you may have a subscription that you don't want to stay active when the view is detached from the visual tree. It's also useful for setting up things when you get added to the visual tree, although usually the correct place for something like that is in the ViewModel's `WhenActivated`. 
 
diff --git a/docs/documentation/handbook/when-any.md b/docs/documentation/handbook/when-any.md
deleted file mode 100644
index 67670ecf..00000000
--- a/docs/documentation/handbook/when-any.md
+++ /dev/null
@@ -1,287 +0,0 @@
----
-Order: 24
----
-# WhenAny
-
-[![YouTube](https://img.shields.io/badge/YouTube-ReactiveUI-red?logo=youtube)](https://www.youtube.com/watch?v=IH2yx7b9DNY)
-
-In interactive UI applications, state is continually changing in response to user actions and application events. ReactiveUI enables you to express changes to application state as streams of values and combine and manipulate them using the operators of [ReactiveUI.Primitives](../primitives/index.md).
-
-The motivation is intuitive enough when you think about it. It's not hard to imagine that changes to a property can be considered events - that's how `INotifyPropertyChanged` works. From there, the same argument for using streams over events applies. In the context of MVVM application design specifically, modelling property changes as observables leads to several advantages:
-
-- The logic of an application can be defined in terms of changes to properties
-- This logic can be composed and expressed declaratively, using the power of stream operators
-- Concepts like time and asynchronicity become easier to reason about, due to their first-class treatment in an Observable context.
-
-ReactiveUI provides several variants of `WhenAny` to help you work with properties as an observable stream.
-
-## What is WhenAny
-
-`WhenAny` is a set of extension methods, each starting with the prefix `WhenAny`, that allow you to get notifications when properties on objects change.
-
-You can think of the `WhenAny` as a set of extension methods notifying you when one or many property values have changed.
-
-`WhenAny` supports multiple property types including `INotifyPropertyChanged`, `DependencyProperty` and `BindableProperty`. 
-
-It will check the property for support for each of those property types, and when you `Subscribe()` it will subscribe to the events offered by the applicable property notification mechanism.
-
-`WhenAny` by default is just a wrapper around these property notification events, and won't store any values before a `Subscribe`. You can use [sharing operators](../primitives/sharing.md) such as `ShareLive` and `ReplayLive` to get it to store these values.
-
-You can also wrap the `WhenAny` in a `Signal.Lazy` to avoid the value being calculated until a `Subscribe` has happened. This is useful for `ObservableAsPropertyHelper` when you're using the defer feature.
-
-## Basic syntax
-
-The following examples demonstrate simple uses of `WhenAnyValue`; the `WhenAny` variant you are likely to use most frequently.
-
-## WhenAnyValue
-
-<div class="youtube-video-container"><iframe src="https://www.youtube.com/embed/IH2yx7b9DNY" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe></div>
-
-### Watching single property
-
-`WhenAnyValue` will return the initial value of the property, and any subsequent changes to the property.
-
-For example, this returns an observable that yields the current value of `Foo`, and any subsequent changes:
-
-```cs
-this.WhenAnyValue(x => x.Foo)
-```
-
-### Watching a number of properties
-
-This returns an observable that yields a new `Color` with the values of Red, Green and Blue properties, and then will emit a new value in the observable when any of the property values change.
-
-The final parameter is a selector describing how to combine the three observed properties:
-
-```cs
-this.WhenAnyValue(x => x.Red, x => x.Green, x => x.Blue, 
-                  (r, g, b) => new Color(r, g, b));
-```
-
-### Watching a nested property
-
-`WhenAny` variants can observe nested properties for changes, too:
-
-```cs
-this.WhenAnyValue(x => x.Foo.Bar.Baz);
-```
-
-Presuming the properties between `Foo.Bar.Baz` are not null it will emit the current value and then any subsequent values.
-
-If either `Foo` or `Bar` are null then the value of `Baz` won't be emitted.
-
-### Usage
-
-Below are some typical usages of the observables returned by the `WhenAny` variants:
-
-#### Subscribing
-
-You can `Subscribe` to the observable returned by the `WhenAny` variant and get notifications whenever the value changes.
-
-```cs
-this.WhenAnyValue(x => x.SearchText)
-    .Subscribe(x => Console.WriteLine(x));
-```
-
-This will subscribe to whenever the current object's `SearchText` is changed and print the value to the `Console.WriteLine` method.
-
-#### Exposing 'calculated' properties
-
-In general, using `Subscribe` on a `WhenAny` observable (or any observable, for that matter) just to set a property is likely a code smell. Idiomatically, the `ToProperty` operator is used to create a 'read-only' calculated property that can be exposed to the rest of your application, only settable by the `WhenAny` chain that preceded it:
-
-```cs
-this.WhenAnyValue(x => x.SearchText, x => x.Length, (text, length) => text + " (" + length + ")")
-    .ToProperty(this, x => x.SearchTextLength, out _searchTextLength);
-```
-
-This will set an ([ObservableAsPropertyHelper](observable-as-property-helper.md) property) field called `_searchTextLength` which you then expose via the `SearchTextLength` property. `ObservableAsPropertyHelper` properties cannot be mutated directly, but are instead calculated via the `WhenAnyValue` selector lambda.
-
-See the [ObservableAsPropertyHelper](observable-as-property-helper.md) section for more information on this pattern.
-
-#### `ReactiveCommand.CanExecute` observable
-
-`WhenAny` can be used for providing logic if a `ReactiveCommand` can be executed or not.
-
-```cs
-var canCreateUser = this.WhenAnyValue(
-    x => x.Username, x => x.Password, 
-    (user, pass) => 
-        !string.IsNullOrWhiteSpace(user) && 
-        !string.IsNullOrWhiteSpace(pass) && 
-        user.Length >= 3 && 
-        pass.Length >= 8)
-    .Unique();
-
-CreateUserCommand = ReactiveCommand.CreateFromTask(CreateUser, canCreateUser); 
-```
-
-Here, `WhenAnyValue` is used to observe the changing values of the `Username` and `Password` fields, and the selector will determine if the `CreateUserCommand` can be executed, preventing the user from executing the command until the validation conditions are met.
-
-#### Invoking commands
-
-Commands are often bound to buttons or controls in the view that can be triggered by the user. You can also trigger commands when a property value has changed.
-
-```cs
-// In the ViewModel.
-this.WhenAnyValue(x => x.SearchText)
-    .Where(x => !String.IsNullOrWhiteSpace(x))
-    .Calm(TimeSpan.FromSeconds(.25))
-    .InvokeCommand(SearchCommand);
-
-// In the View.
-this.Bind(ViewModel, vm => vm.SearchText, v => v.SearchTextField.Text);
-```
-
-Above, whenever the `SearchText` property has changed, and a quarter second has passed since the last change, the `InvokeCommand` will cause the `SearchCommand` to be invoked.
-
-The view will Bind to the `SearchText` property which will trigger the command automatically.
-
-#### Performing view-specific transforms as an input to `BindTo`
-
-Ideally, controls on your view bind directly to properties on your view model. In cases where you need to convert a viewmodel value to a view-specific value (e.g. `bool` to `Visibility`), you should register a `BindingConverter`. Still, you may come across a situation in which you want to perform a transformation in the view directly. Here, we observe the `ShowToolTip` property of the view model, transform the `true`/`false` values to `1` and `0` respectively, then bind the result to the `ToolTipLabel`'s alpha property. 
-
-```cs
-// In the View.
-ViewModel.WhenAnyValue(x => x.ShowToolTip)
-         .Select(show => show ? 1f : 0f)
-         .BindTo(this, x => x.ToolTipLabel.Alpha);
-```
-
-The preferable option is to use the `OneWayBind` property to perform the binding.
-
-```cs
-this.OneWayBind(this.ViewModel, vm => vm.ShowToolTip, view => view.ToolTipLabel.Alpha, show => show ? 1f : 0f);
-```
-
-## WhenAny
-
-`WhenAny` allows you to get the Sender and the Expression passed into the `WhenAny`. This is useful for scenarios where the `Sender` is important such as View's where you need to know the Control which invoked the Property Change.
-
-`WhenAny` will pass an `ObservedChange` object, which exposes the following properties:
-
-* `Value` - the updated value
-* `Sender` - the object whose property has changed 
-* `Expression` - the expression that changed. Not needed often for external users.
-
-
-```cs
-this.WhenAny(x => x.ComboBox.SelectedItem).Subscribe(x => Console.WriteLine($"The {x.Sender} changed value to {x.Value}"));
-```
-
-Above, we write out the `Sender` and the new property value of the `SelectedItem`.
-
-`WhenAnyValue` should be preferred over `WhenAny` where possible and you don't need to know the `Sender` or the `Expression`.
-
-## WhenAnyObservable
-
-`WhenAnyObservable` observes one or multiple observables and provides the latest observable value, handles automatic subscriptions of the new observable and disposal of previous observables.  `WhenAnyObservable` by default will be a lazy subscription, this means you will not get a value until you subscribe.
-
-```csharp
-public class MyViewModel
-{
-    [Reactive]
-    public Document Document { get; set; }
-
-    public MyViewModel()
-    {
-      this.WhenAnyObservable(x => x.Document.IsSaved).Subscribe(x => Console.WriteLine($"Document Saved: {x}"));
-    }
-}
-
-public class Document
-{
-    public IObservable<bool> IsSaved { get; }
-}
-```
-
-Above whenever the document is saved, it will print the value from the `IsSaved` observable.  It will automatically unsubscribe and re-subscribe when the `Document` property is changed.
-
-## Additional Considerations
-
-### Property Changed Notifications needed
-Using `WhenAny` variants is fairly straightforward. However, there are a few aspects of their behaviour that are worth highlighting.
-
-`WhenAny` variants support a wide range of property changed notifications. For example it can support `INotifyPropertyChanged` for your view models, `DependencyProperty` on windows based XAML platforms, `NSObject` property changed notifications on Apple. To get value changed notifications your object must implement one of these known property changed notification mechanisms. 
-
-If one of these isn't supported you will only get the initial value of the property and won't have any notifications of updates. Additionally, a warning will be issued at run time (ensure you have registered a service for `ILogger` to see this).
-
-Commonly on your view model you will use `INotifyPropertyChanged` which the `ReactiveObject` supports, where you'll commonly use ReactiveUI's `RaiseAndSetIfChanged` or raise the standard `INotifyPropertyChanged` events
-
-### `WhenAny` has cold observable and behavioural semantics
-
-`WhenAny` is a purely cold Observable, which eventually directly connects to UI component events. For events such as `DependencyProperties`, this could potentially be a minor place to optimize, via `Publish`. When chaining to `ToProperty` (another cold operator), the target `ObservableAsPropertyHelper` must be read (`.Value`) or observed (e.g. used in a binding or used as part of another `WhenAny` with a subscription), for any part of the chain to execute. 
-
-Additionally, `WhenAny` always provides you with the current value as soon as you subscribe to it - in this sense it is effectively a `BehaviorSubject`.
-
-### `WhenAny` will not propagate `NullReferenceException`s within the watched expression
-
-`WhenAny` will only send notifications if reading the given expression would not throw a `NullReferenceException`. Consider the following code:
-
-```cs
-this.WhenAny(x => x.Foo.Bar.Baz, _ => "Hello!")
-    .Subscribe(x => Console.WriteLine(x));
-
-// Example 1
-this.Foo.Bar.Baz = null;
->>> Hello!
-
-// Example 2: Nothing printed!
-this.Foo.Bar = null;
-
-// Example 3
-this.Foo.Bar = new Bar() { Baz = "Something" };
->>> Hello!
-```
-
-In Example 1, even though `Baz` is null, because the expression could be evaluated, you get a notification.
-
-In Example 2 however, evaluating this.Foo.Bar.Baz wouldn't give you null, it would crash. `WhenAny` therefore suppresses any notifications from being generated. Setting `Bar` to a new value generates a new notification.
-
-### `WhenAny` only notifies on change of the output value
-
-`WhenAny` only tells you when the final value of the input expression has changed. This is true even if the resulting change is because of an intermediate value in the expression chain. Here's an explaining example:
-
-```cs
-this.WhenAny(x => x.Foo.Bar.Baz, _ => "Hello!")
-    .Subscribe(x => Console.WriteLine(x));
-
-// Example 1
-this.Foo.Bar.Baz = "Something";
->>> Hello!
-
-// Example 2: Nothing printed!
-this.Foo.Bar.Baz = "Something";
-
-// Example 3: Still nothing
-this.Foo.Bar = new Bar() { Baz = "Something" };
-
-// Example 4: The result changes, so we print
-this.Foo.Bar = new Bar() { Baz = "Else" };
->>> Hello!
-```
-
-Notably, in Example 3, even though the intermediate `Bar` object was replaced with a new instance, no change is fired - as the result of the full `Foo.Bar.Baz` expression has not changed.
-
-### null propogation inside `WhenAnyValue`
-`WhenAnyValue` is not directly able to perform null propogation due to the fact Expressions don't support this feature yet.
-
-You can simulate null propogation support by chaining your `WhenAnyValue()` call to each property along the way. Here's an example:
-
-```cs
-this.WhenAnyValue(x => x.Foo, x => x.Foo.Bar, x => x.Foo.Bar.Baz, (foo, bar, baz) => foo?.Bar?.Baz)
-    .Subscribe(x => Console.WriteLine(x));
-```
-
-## How WhenAny knows about different type of properties
-
-`WhenAny` operators will look for services registered with Splat with the `ICreatesObservableForProperty` interface.
-
-The interface has two methods, `GetAffinityForObject` and `GetNotificationForProperty`.
-
-The first method `GetAffinityForObject` based on the property type, property name, and it should notify before or after the property change, will ask for a "vote" on how confident the property changed observable is at converting the value. A value of 0 from `GetAffinityForObject` means it cannot create a property changed observable at all. The system will then take votes from all registered `ICreatesObservableForProperty` interfaces and the one with the highest numeric vote wins. In the worst case a `POCOObservableForProperty` will always have a value greater than 0. This type of property changed observable will only get the initial value for the property and never update.
-
-After the voting has finished it will call `GetNotificationForProperty` with the property type, name and if it should be before or after the property changed. It will then create the property changed observable.
-
-When you are calling as part of a `WhenAny` chain it will get the property changed observable for each property along the chain.
-
-So for instance `this.WhenAnyValue(x => x.Property1.Property2)` will get the property changed observables for the Property1, then for the Property2. So each can be a different type of observable property, for example a `INotifyPropertyChanged` and a `DependencyObject`.
diff --git a/docs/documentation/primitives/extensions/state-and-testing.md b/docs/documentation/primitives/extensions/state-and-testing.md
index 4e3e8a38..20cfe7ff 100644
--- a/docs/documentation/primitives/extensions/state-and-testing.md
+++ b/docs/documentation/primitives/extensions/state-and-testing.md
@@ -115,7 +115,7 @@ name: 'Grace'
 The lambda must read one property directly, such as `p => p.Name`. A lambda that calls a method, such as
 `p => p.ToString()`, throws `ArgumentException`. The helper works with trimming and Native AOT.
 
-In a ReactiveUI app, [`WhenAnyValue`](../../handbook/when-any.md) does this job for view models and follows chains of
+In a ReactiveUI app, [`WhenAnyValue`](../../binding/observing.md) does this job for view models and follows chains of
 properties.
 
 ## Running code on subscribe and dispose
diff --git a/docs/documentation/primitives/signals.md b/docs/documentation/primitives/signals.md
index b30c4548..3ee6d5ae 100644
--- a/docs/documentation/primitives/signals.md
+++ b/docs/documentation/primitives/signals.md
@@ -320,7 +320,7 @@ Pass an `IEqualityComparer<T>` as a third argument to skip a value that equals t
 comparer, a change event that leaves the value the same still sends it again.
 
 Watching properties is exactly what ReactiveUI's `WhenAnyValue` does for you, so in a ReactiveUI app you rarely
-need to build this by hand. See [WhenAny](../handbook/when-any.md).
+need to build this by hand. See [WhenAny](../binding/observing.md).
 
 ## Sending from many threads
 
diff --git a/docs/documentation/reactive-programming/observables.md b/docs/documentation/reactive-programming/observables.md
index f6e074bb..866f62b7 100644
--- a/docs/documentation/reactive-programming/observables.md
+++ b/docs/documentation/reactive-programming/observables.md
@@ -56,7 +56,7 @@ Ada Lovelace
 
 | Source | Stream |
 |---|---|
-| A property | `WhenAnyValue`. See [WhenAny](../handbook/when-any.md). |
+| A property | `WhenAnyValue`. See [WhenAny](../binding/observing.md). |
 | A command | `ReactiveCommand` is a stream of its results, and `IsExecuting` and `ThrownExceptions` are streams too. See [commands](../handbook/commands/index.md). |
 | An event | `Events()` from the [observable events generator](../handbook/observable-events/index.md), or [`Signal.FromEvent`](../primitives/creation-factories.md#from-an-event). |
 | A task | [`Signal.FromAsync`](../primitives/creation-factories.md). |
diff --git a/docs/documentation/reactive-programming/operators.md b/docs/documentation/reactive-programming/operators.md
index a7ee8b3f..e963e846 100644
--- a/docs/documentation/reactive-programming/operators.md
+++ b/docs/documentation/reactive-programming/operators.md
@@ -111,7 +111,7 @@ cannot run. [Your first pipeline](#your-first-pipeline) shows it. See [commands]
 ### `WhenAnyValue` and `WhenAnyObservable`
 
 `WhenAnyValue` makes a stream from properties. `WhenAnyObservable` follows a property that itself holds a stream, such
-as a command on a child view model. See [WhenAny](../handbook/when-any.md).
+as a command on a child view model. See [WhenAny](../binding/observing.md).
 
 ## Every other operator
 
diff --git a/nuget-packages.json b/nuget-packages.json
index 93dc6ef3..2dabfcf8 100644
--- a/nuget-packages.json
+++ b/nuget-packages.json
@@ -33,6 +33,7 @@
     "ReactiveMarbles.PropertyChanged.SourceGenerator",
     "ReactiveMarbles.RoslynHelpers",
     "ReactiveMarbles.SourceGenerator.TestNuGetHelper",
+    "ReactiveUI.Binding",
     "ReactiveUI.Binding.Analyzer",
     "ReactiveUI.Binding.SourceGenerators",
     "ReactiveUI.Disposables",