Breaking changes in Avalonia 12

This page lists all the breaking changes between Avalonia 11 and 12 and provides migration guidance and alternatives.

.NET support updated

Avalonia version 12 dropped support for .NET Framework and .NET Standard. Only .NET 8 and later are supported. The recommended target is .NET 10.

If your project targets Android or iOS, only .NET 10 is supported. This is to match the support Microsoft provides for the underlying .NET SDK.

Update your Avalonia projects to a supported .NET version.

Example:

-<TargetFramework>netstandard2.0</TargetFramework>
+<TargetFramework>net10.0</TargetFramework>

PR: #19869

Avalonia version 12

The major version of Avalonia is now 12, up from 11.

Upgrade all Avalonia package references to the latest 12 patch version, either in your favorite IDE or by editing the project files.
Choose the latest release from the official GitHub Releases page.

Example:

-<PackageReference Include="Avalonia" Version="11.3.12" />
+<PackageReference Include="Avalonia" Version="12.0.0" />
-<PackageReference Include="Avalonia.Themes.Fluent" Version="11.3.12" />
+<PackageReference Include="Avalonia.Themes.Fluent" Version="12.0.0" />

Avalonia.Diagnostics package removed

The Avalonia.Diagnostics package has been removed. The Dev Tools included with Avalonia Accelerate should be used instead.

Remove the Avalonia.Diagnostics package from your projects and replace it with AvaloniaUI.DiagnosticsSupport.
To install the Accelerate Dev Tools, see the Dev Tools documentation.

Example:

Project file:

-<PackageReference Include="Avalonia.Diagnostics" Version="11.3.12" />
+<PackageReference Include="AvaloniaUI.DiagnosticsSupport" Version="2.2.0" />

Application file:

-AttachDevTools();
+AttachDeveloperTools();

PR: #20332

Binding class hierarchy changes

The binding class hierarchy has changed. Bindings defined in XAML files (e.g., {Binding}) are unaffected. However, you must update binding usages in C# code.

The IBinding interface has been removed. Its replacement is the BindingBase class.

All types of bindings now inherit from BindingBase: ReflectionBinding, CompiledBinding, TemplateBinding, and IndexerBinding. Adjust your usage accordingly; don't assume that a BindingBase instance represents only a "standard" binding.

The Binding class is kept for compatibility and always corresponds to ReflectionBinding. To create bindings in code, use the CompiledBinding and ReflectionBinding classes directly.

The InstancedBinding class has also been removed. Its direct equivalent is BindingExpressionBase, which represents a binding applied to a given object and property.

Example:

 public record Item(string Value);

-var reflectionBinding = new Binding("SomeProperty");
 var reflectionBinding = new ReflectionBinding(nameof(Item.Value));

+var compiledBinding = CompiledBinding.Create((Item item) => item.Value);

PR: #19589, #20439

Compiled bindings are enabled by default

<AvaloniaUseCompiledBindingsByDefault> is now true by default.
Any Binding usage in XAML code now maps to CompiledBinding.

Avalonia's official templates explicitly enabled this flag in created projects for several years, so recent codebases should not be affected. However, if your project didn't define this flag, it was false in previous versions.

Compiled bindings are recommended whenever possible, as they are more performant than reflection bindings and are checked for correctness at build time.

PR: #19712

Binding plugins removed

The binding plugins were intended as an extensibility point for adding features to bindings. In practice, they were not working with compiled bindings and were effectively unused by most people.

Worse, users often had to turn off the default data annotations validation plugin because it conflicted with popular frameworks such as CommunityToolkit.Mvvm.

Starting with Avalonia v12, plugins are no longer configurable. The data annotations plugin is now disabled by default.

PR: #20623

Configurable text shaper

The text shaper is now configurable independently of the rendering engine. For most applications, this change should be transparent, as HarfBuzz is used by default when UsePlatformDetect is called on the AppBuilder.

However, if your project explicitly configures a rendering engine, such as Skia via UseSkia, an InvalidOperationException with the message No text shaping system configured might be thrown on startup. In this case, the project needs to be updated with a call to UseHarfBuzz on the AppBuilder.

Example:

Project file:

+<PackageReference Include="Avalonia.HarfBuzz" Version="12.0.0" />

Application file:

 AppBuilder.Configure<App>()
     .UseSkia()
+    .UseHarfBuzz()

PR: #19852

Improved touch/pen focus and selection behavior

Selection handling in SelectingItemsControl (and derived controls such as ListBox, ComboBox, TabControl) and TreeView has been unified to provide consistent, platform-appropriate behavior across input devices:

• Touch and pen input now triggers selection on pointer release (not press), matching native platform conventions. This allows swipe and scroll gestures to start on a selectable item without accidentally changing the selection.
• Container types (e.g., ListBoxItem, TreeViewItem) now handle selection input directly instead of letting events bubble up to their parent ItemsControl. Custom logic that relied on intercepting selection events at the ItemsControl level must be moved to the container or to an override of UpdateSelectionFromEvent.
• Focus is changed only on release for touch and pen devices.

Obsoleted APIs

The following methods on SelectingItemsControl are obsoleted and will be removed in a future version:

Obsoleted method	Replacement
UpdateSelection	UpdateSelectionFromEvent
UpdateSelectionFromEventSource	UpdateSelectionFromEvent

Customizing selection behavior

Override ShouldTriggerSelection on SelectingItemsControl or TreeView to control which pointer or key events initiate selection. Override UpdateSelectionFromEvent to customize how selection is applied.

The static ItemSelectionEventTriggers class provides helper methods for checking modifiers:

Method	Description
ShouldTriggerSelection(InputElement, PointerEventArgs)	Determines whether a pointer event should trigger selection.
ShouldTriggerSelection(InputElement, KeyEventArgs)	Determines whether a key event should trigger selection.
HasRangeSelectionModifier(InputElement, RoutedEventArgs)	Checks for the Shift modifier (range select).
HasToggleSelectionModifier(InputElement, RoutedEventArgs)	Checks for the Ctrl modifier (toggle select).

PR: #19203, #19753

TopLevel changes

To prepare the groundwork for advanced windowing features, notably templated drawn window decorations and virtual window scenarios, several changes happened in Avalonia v12:

• Despite its name, a TopLevel (this includes Window) object is not necessarily at the root of the visual hierarchy anymore. Code that casts the top Visual to TopLevel no longer works. To access a TopLevel instance, always call TopLevel.GetTopLevel(Visual).
• Interfaces that were previously only implemented by TopLevel classes, such as IInputRoot, IRenderRoot, ILayoutRoot, ITextInputMethodRoot and IEmbeddableLayoutRoot, are either removed or not accessible anymore. Use TopLevel instead.
• A new IPresentationSource interface is introduced, which represents an arbitrary host for the visual tree (while not being a visual itself). To get a hold of such an instance, call the new GetPresentationSource(Visual) extension method.

PR: #20624

Window decoration changes

Avalonia v12 overhauls how the decorations (title bar, caption buttons, resize grips, and similar elements) of a window are drawn when the system chrome is not used:

• A new WindowDrawnDecorations class is added. Its role is to provide all the window decorations through a single control.
• Thanks to this new type, the TitleBar, CaptionButtons and ChromeOverlayLayer types are not necessary anymore and have been removed.
• The Window.ExtendClientAreaChromeHints property consisted of several flags that were not always behaving as expected. This property has been removed, as the WindowDecorations property in conjunction with ExtendClientAreaToDecorationsHint should be used instead.

PR: #20770, #20732, #20796

Clipboard changes

In a previous version, clipboard support was rewritten to use a new IAsyncDataTransfer interface and related types. To avoid breaking compatibility, the old IDataObject interface was kept (and made obsolete) as a shim for the new system.

The IDataObject interface has been removed in Avalonia v12, along with all methods that accept that type. Its implementation, DataObject, no longer does anything.

The IClipboard interface has been simplified, with methods for reading specific formats implemented as extension methods (such as TryGetTextAsync and TryGetFile).

Read the official clipboard documentation for details on using IAsyncDataTransfer.

Example:

// Setting a data object on the clipboard
-var data = new DataObject();
-data.Set(DataFormats.Text, "some text");
+var item = new DataTransferItem();
+item.Set(DataFormat.Text, "some text");
+var data = new DataTransfer();
+data.Add(item);

-await clipboard.SetDataObjectAsync(data);
+await clipboard.SetDataAsync(data);

Example:

// Reading text from the clipboard
-var text = await clipboard.GetTextAsync();
+var text = await clipboard.TryGetTextAsync();

PR: #20521

Multiple dispatchers support

While not technically a breaking change, Avalonia v12 now supports multiple dispatchers, one per thread.

Using Dispatcher.UIThread is still perfectly acceptable for applications. However, library and control authors should start using the AvaloniaObject.Dispatcher and Dispatcher.CurrentDispatcher properties to support multiple dispatchers properly.

Multiple UI threads are currently still unsupported.

PR: #18686

Dispatcher.InvokeAsync captures the execution context

This change should make most usages of asynchronous calls behave as the user would expect. AsyncLocal will work as expected, and impersonation and culture will flow from the caller.

PR: #19163

FuncMultiValueConverter accepts an IReadOnlyList

The converter function parameter changed from IEnumerable<TIn> to IReadOnlyList<TIn>, allowing you to access values by index (e.g., values[0]) without converting to an intermediate collection. Since IReadOnlyList<T> extends IEnumerable<T>, most existing usages that iterate or use LINQ are unaffected. Code that explicitly declares the lambda parameter type as IEnumerable<TIn> will need to be updated.

PR: #19936

Data validation enabled by default in custom controls

Before v12, Avalonia properties with enableDataValidation: true required overriding the UpdateDataValidation method for data validation errors to be reported for that property. Now it happens automatically.

You should remove UpdateDataValidation overrides that only call DataValidationErrors.SetError.

Example:

 public class CustomControl
 {

     public static readonly StyledProperty<string?> CustomProperty = 
         AvaloniaProperty.Register<CustomControl, string?>("Custom", enableDataValidation: true)); 

-    protected override void UpdateDataValidation(AvaloniaProperty property, BindingValueType state, Exception? error)
-    {
-        if (property == CustomProperty)
-        {
-            DataValidationErrors.SetError(this, error);
-        }
-    } 
 }

If you need to revert to the old behavior for a given property, override UpdateDataValidation and do not call the base method for that property.

PR: #20067

Render target and platform surface interfaces reworked

Several internal rendering interfaces have been restructured:

• IRenderTarget.CreateDrawingContext now takes a RenderTargetSceneInfo parameter instead of multiple overloads.
• IRenderTargetBitmapImpl no longer extends IRenderTarget. It now extends IReadableBitmapImpl with a simpler CreateDrawingContext() method.
• IDrawingContextLayerImpl no longer extends IRenderTargetBitmapImpl. It now extends IBitmapImpl directly.
• Platform surfaces use the typed IPlatformRenderSurface interface instead of IEnumerable<object>.
• ISkiaGpu is now internal.

Several versioned and split interfaces have been merged into their base types:

• IRenderTarget2 and IRenderTargetWithProperties merged into IRenderTarget.
• IGlPlatformSurfaceRenderTarget2 and IGlPlatformSurfaceRenderTargetWithCorruptionInfo merged into IGlPlatformSurfaceRenderTarget.
• ISkiaGpuRenderTarget2 merged into ISkiaGpuRenderTarget.
• ISkiaGpuWithPlatformGraphicsContext merged into ISkiaGpu.

Additionally, alpha format handling has been consolidated:

• ILockedFramebuffer now includes an AlphaFormat property.
• IReadableBitmapImpl now includes an AlphaFormat? property, replacing the separate IReadableBitmapWithAlphaImpl interface.
• Bitmap.CopyPixels() no longer accepts an AlphaFormat parameter. The alpha format is now read from the ILockedFramebuffer directly.
• The LockedFramebuffer constructor requires an AlphaFormat parameter.

The IPlatformRenderInterfaceContext.CreateOffscreenRenderTarget method signature changed from (PixelSize, double) to (PixelSize, Vector, bool), where the double scaling factor is replaced by a Vector for per-axis scaling and a bool for text antialiasing control. A new MaxOffscreenRenderTargetPixelSize property was also added to the interface.

These changes only affect code that implements custom rendering backends or directly consumes platform-level rendering interfaces. Application code using RenderTargetBitmap or standard drawing APIs is not affected.

PRs: #20811, #20556, #20557, #20497

Text formatting constructors modified

GenericTextRunProperties, TextCollapsingProperties, and TextShaperOptions all had two constructors: one with a FontFeatureCollection parameter, and one without.

They have been merged into a single constructor with an optional parameter. Depending on the overload used, you might need to reorder the arguments, since FontFeatureCollection is now the last parameter.

PR: #20527

Access keys are triggered by symbol

Previously, the underlying virtual key triggered access keys, so accented characters or numbers could not be used as access keys.

To align with other popular UI frameworks and user expectations, access keys are now triggered by the symbol printed on the key. This means accented characters (e.g., _é) and numbers (e.g., _2) now work as access keys.

The AccessText.AccessKey property type changed from char to string? to support multi-byte Unicode characters. Code that reads this property will need to be updated.

PR: #20662

Font support updated

To ensure consistent font loading across platforms, Avalonia v12 includes its own font parser.

Some legacy fonts that are not TrueType (.ttf) or OpenType (.otf) are no longer supported. Such fonts include the ancient Type 1 Font format (.pfb/.pfm).

PR: #19852

Screen is abstract

The Screen class has several internal implementations, and the base class was constructible only for legacy reasons.

In Avalonia v12, it is now abstract. Do not construct a Screen class. Instead, get an existing instance from its members (for example, Screens.All, Screens.Primary, Screens.ScreenFromWindow).

PR: #20529

ResourcesChangedEventArgs is a struct

For performance purposes, ResourcesChangedEventArgs is now a struct.

Most projects never construct instances of this type, as it's mainly used through the StyledElement.ResourcesChanged event. If you did construct ResourcesChangedEventArgs, call ResourceChangedEventArgs.Create instead.

PR: #20576

Gesture events moved

All the attached events previously declared in the Gestures class (such as ScrollGesture, Pinch, and others) have been moved to InputElement, making them available to all elements by default. Remove the Gestures. prefix from your XAML files.

The Gestures class is not public anymore.

Example:

-<Button Gestures.Pinch="Button_Pinch" />
+<Button Pinch="Button_Pinch" />

PR: #20789

Windows

Direct2D1 support removed

Avalonia no longer provides a Direct2D rendering backend. This package was not maintained, and did not have feature and performance parity with the Skia backend. The Skia backend is now the recommended rendering backend for all usages.

Example:

Project file:

-<PackageReference Include="Avalonia.Direct2D1" Version="11.3.12" />
+<PackageReference Include="Avalonia.Skia" Version="12.0.0" />

Application file:

 AppBuilder.Configure<App>()
-    .UseDirect2D1()
+    .UseSkia()

PR: #20132

BinaryFormatter removed

In previous versions, Avalonia used .NET's BinaryFormatter on Windows to implicitly serialize and deserialize arbitrary objects placed on the clipboard.

Microsoft has been recommending migrating away from the binary formatter since several .NET versions. Avalonia follows this guidance and no longer uses it.

Your project should explicitly serialize and deserialize objects using your preferred mechanism (JSON is a popular format).

PR: #20455

Window.ExtendClientAreaToDecorationsHint improved

On Windows, several issues with the ExtendClientAreaToDecorationsHint property have been fixed, and this property now works in all supported scenarios. Previously, various workarounds were suggested, such as adding or removing margins in the affected window (notably when the window is maximized). All earlier workarounds should now be removed.

PR: #20217

Android

App initialization changed

In Avalonia 12, the way an Android application and its activities are initialized has changed, allowing subsequent activities to properly use the Application class defined in your project.

1. Change your main activity to inherit from AvaloniaMainActivity (non-generic) instead of AvaloniaMainActivity<TApp> (generic).
2. Add a new class deriving from AvaloniaAndroidApplication<TApp> and apply the [Android.App.Application] attribute to it.

Example:

[Activity]
public class MainActivity :
-AvaloniaMainActivity<App>
+AvaloniaMainActivity
{
}

+[Application]
+public class AndroidApp : AvaloniaAndroidApplication<App>
+{
+    protected AndroidApp(IntPtr javaReference, JniHandleOwnership transfer)
+        : base(javaReference, transfer)
+    {
+    }
+}

PR: #18756

IActivityApplicationLifetime replaces ISingleViewApplicationLifetime

Android now uses IActivityApplicationLifetime instead of ISingleViewApplicationLifetime. This new interface provides a MainViewFactory property (a Func<Control>) instead of a single MainView instance, because Android can create multiple activity instances during the app's lifetime.

Update your App.axaml.cs to check for IActivityApplicationLifetime before ISingleViewApplicationLifetime:

 public override void OnFrameworkInitializationCompleted()
 {
     if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
         desktop.MainWindow = new MainWindow();
+    else if (ApplicationLifetime is IActivityApplicationLifetime activityLifetime)
+        activityLifetime.MainViewFactory = () => new MainView();
     else if (ApplicationLifetime is ISingleViewApplicationLifetime singleView)
         singleView.MainView = new MainView();
     base.OnFrameworkInitializationCompleted();
 }

The ISingleViewApplicationLifetime check is still needed for iOS, browser, and embedded Linux platforms.

PR: #18893

Removed CreateAppBuilder and CustomizeAppBuilder from AvaloniaMainActivity

The CreateAppBuilder() and CustomizeAppBuilder(AppBuilder) virtual methods have been removed from AvaloniaMainActivity. These methods were previously marked as obsolete and are no longer called by the framework. App initialization is now handled entirely through AvaloniaAndroidApplication<TApp>, as described in the section above.

If you were overriding these methods, move that logic into your AvaloniaAndroidApplication<TApp> subclass or your App class instead.

PR: #20715

iOS

App initialization changed

In Avalonia 12, the way an iOS application is initialized has changed to use the "scenes" concept, which Apple will make mandatory in the near future.

While most applications should work without any code changes, AvaloniaAppDelegate.Window will now remain null after the app is initialized, as the window is now managed internally by the scene delegate.

If you need to access the UIWindow, override the AvaloniaView.MovedToWindow method to detect when the view gets attached to it.

PR: #20454

Browser

Avalonia.Browser.Blazor package removed

The Avalonia.Browser.Blazor package served as a temporary migration step during the upgrade from Avalonia's old Blazor-based browser backend. Avalonia has now fully moved to a new backend based on WASM (Avalonia.Browser). This package was no longer maintained and has been removed.

It is still possible to run Avalonia on top of Blazor by using the supported Avalonia.Browser package and its AvaloniaView class.

PR: #20105

Tizen

Avalonia.Tizen package removed

The Tizen platform is no longer supported out of the box because it lacked a maintainer. Read Moving Tizen Support Out of Main Repository for details.

PR: #19722

Headless

xUnit.net and NUnit supported versions updated

The underlying test frameworks supported by Avalonia's headless platform have been updated to their latest versions. The unit tests might need updates.

• xUnit.net support now targets version 3 (up from 2). Read xUnit.net's official migration guide for how to migrate your unit tests.
• NUnit support now targets version 4 (up from 3). Read NUnit's official migration guide for how to migrate your unit tests.

PR: #20372, #20481

Removed members

The following members have been removed in Avalonia 12. They are grouped by the feature area that motivated the removal.

Binding class hierarchy

See Binding class hierarchy changes for context.

Removed member	Replacement	PR
IBinding interface	BindingBase	#19589
InstancedBinding class	BindingExpressionBase	#19589

Binding plugins

See Binding plugins removed for context. Remove all usages of these types.

Removed member	PR
Avalonia.Data.Core.Plugins.BindingPlugins	#20623
Avalonia.Data.Core.Plugins.DataValidationBase	#20623
Avalonia.Data.Core.Plugins.ExceptionValidationPlugin	#20623
Avalonia.Data.Core.Plugins.IDataValidationPlugin	#20623
Avalonia.Data.Core.Plugins.IndeiValidationPlugin	#20623
Avalonia.Data.Core.Plugins.IPropertyAccessorPlugin	#20623
Avalonia.Data.Core.Plugins.IStreamPlugin	#20623
Avalonia.Data.Core.Plugins.PropertyAccessorBase	#20623
Avalonia.Data.Core.Plugins.PropertyError	#20623

Clipboard and drag-drop

See Clipboard changes for context.

Removed member	Replacement	PR
DataFormats.* members	DataFormat.*	#20521
DataObject.* members	DataTransfer	#20521
DataObjectExtensions class	AsyncDataTransferExtensions	#20521
DragDrop.DoDragDrop method	DragDrop.DoDragDropAsync	#20521
DragEventArgs.Data property	DragEventArgs.DataTransfer	#20521
IDataObject interface	IAsyncDataTransfer	#20521
IClipboard.GetDataAsync	IClipboard.TryGetDataAsync	#20521
IClipboard.GetFormatsAsync	ClipboardExtensions.GetDataFormatsAsync	#20521
IClipboard.GetTextAsync	ClipboardExtensions.TryGetTextAsync	#20521
IClipboard.SetTextAsync	ClipboardExtensions.SetTextAsync	#20521
IClipboard.TryGetInProcessDataObjectAsync	IClipboard.TryGetInProcessDataAsync	#20521

TopLevel

See TopLevel changes for context.

Removed member	Replacement	PR
IInputRoot interface	TopLevel	#20624
ITextInputMethodRoot interface	TopLevel	#20624
IEmbeddedLayoutRoot interface	TopLevel	#20624
ILayoutRoot interface	TopLevel	#20624
IRenderRoot interface	TopLevel	#20624
LayoutManager class	ILayoutManager	#20624
TopLevel.PlatformSettings property	VisualExtensions.GetPlatformSettings	#20624
TopLevel.PointerOverElement property	Remove usages	#20624
TopLevel.StartRendering/StopRendering	Embedding.StartRendering/StopRendering	#20624
VisualExtensions.GetVisualRoot method	GetPresentationSource + IPresentationSource.RootVisual	#20624

Window decorations

See Window decoration changes for context.

Removed member	Replacement	PR
Chrome.CaptionButtons class	WindowDrawnDecorations	#20770
Chrome.TitleBar class	WindowDrawnDecorations	#20770
ChromeOverlayLayer class	WindowDrawnDecorations	#20732
VisualLayerManager.AdornerLayer property	AdornerLayer.GetAdornerLayer	#20732
VisualLayerManager.ChromeOverlayLayer property	WindowDrawnDecorations	#20732
VisualLayerManager.LightDismissOverlayLayer property	Remove usages	#20732
VisualLayerManager.OverlayLayer property	OverlayLayer.GetOverlayLayer	#20732
Window.ExtendClientAreaChromeHints property	Window.WindowDecorations	#20770
SystemDecorations enum	WindowDecorations	#20796
ExtendClientAreaChromeHints enum	WindowDecorations	#20770
IPopupHostProvider interface	Popup	#20732
IPopupHost interface	Popup	#20597
LightDismissOverlayLayer class	VisualLayerManager	#20732
OverlayPopupHost.CreatePopupHost method	Popup	#20597

Gesture events

See Gesture events moved for context.

Removed member	Replacement	PR
Gestures class (all attached events)	Events on InputElement	#20789

Other specific removals

Removed member	Replacement	Notes	PR
ResourcesChangedEventArgs.Empty	ResourcesChangedEventArgs.Create	See ResourcesChangedEventArgs is a struct	#20576
TextInputMethodClient.ShowInputPanel	InputPaneActivationRequested event	Showing input panel directly was not correct on all platforms	#20544
NativeMenuBar.EnableMenuItemClickForwarding	Remove usages	Property did nothing	#20577
NativeMenuItemToggleType enum	MenuItemToggleType	Merged with MenuItemToggleType	#20577
IGeometryContext2 interface	IGeometryContext	isStroked/isFilled are now optional parameters on IGeometryContext methods	#20528
IWindowImpl.GetWindowsZOrder	IWindowingPlatform.GetWindowsZOrder	Parameter type changed from Span<Window> to ReadOnlySpan<IWindowImpl>	#20633
AutoCompleteBox.BindingEvaluator	Provide your own implementation	Was an implementation detail exposed publicly	#20596
CharacterReader struct	Provide your own implementation	Was an implementation detail exposed publicly	#19123
StringTokenizer struct	Provide your own implementation	Was an implementation detail exposed publicly	#20544
Data.Core.PropertyPath class	Remove usages	Leftover from previous versions, unused	#19133
Remote.RemoteServer class	Remove usages	Leftover, not working correctly	#20767
Remote.RemoteWidget class	Remove usages	Leftover, not working correctly	#20767

Obsolete since Avalonia 11

The following members were marked obsolete in Avalonia 11 and have now been removed.

Removed member	Replacement	PR
IInsetsManager.DisplayEdgeToEdge	IInsetsManager.DisplayEdgeToEdgePreference	#20617
CustomAnimatorBase / CustomAnimatorBase<T>	InterpolatingAnimator<T>	#20613
CubicBezierEasing	SplineEasing	#20613
AppBuilder.LifetimeOverride	Use any predefined lifetime	#20617
AvaloniaObjectExtensions.Bind	AvaloniaObject.Bind	#20613
IActivatableApplicationLifetime	Application.Current.TryGetFeature<IActivatableLifetime>	#20617
ContextMenu.PlacementMode	ContextMenu.Placement	#20617
FileDialog / FileSystemDialog / SystemDialog	IStorageProvider	#20617
OpenFileDialog	IStorageProvider.OpenFilePickerAsync	#20617
OpenFolderDialog	IStorageProvider.OpenFolderPickerAsync	#20617
SaveFileDialog	IStorageProvider.SaveFilePickerAsync	#20617
ManagedFileDialogExtensions.ShowManagedAsync	IStorageProvider.OpenFilePickerAsync	#20617
ItemContainerGenerator.ContainerFromIndex	ItemsControl.ContainerFromIndex	#20617
ItemContainerGenerator.IndexFromContainer	ItemsControl.IndexFromContainer	#20617
TreeContainerIndex	TreeView	#20617
TreeItemContainerGenerator	ItemContainerGenerator	#20617
ItemsControl.ItemsControlFromItemContaner	ItemsControl.ItemsControlFromItemContainer	#20617
ToggleButton.Checked/Unchecked/Indeterminate events	ToggleButton.IsCheckedChanged	#20617
TabItem.SubscribeToOwnerProperties	Remove usages	#20617
BindingPriority.TemplatedParent	BindingPriority.Template	#20613
CompiledBindingPathBuilder.SetRawSource	CompiledBinding.Source	#20613
Color.ToUint32	Color.ToUInt32	#20613
DrawingContext.PushPreTransform/PushPostTransform/PushTransformContainer	DrawingContext.PushTransform	#20613
ImmutableRadialGradientBrush.Radius	RadiusX and RadiusY	#20613
IRadialGradientBrush.Radius	RadiusX and RadiusY	#20613
RadialGradientBrush.Radius	RadiusX and RadiusY	#20613
IApplicationPlatformEvents	Application.Current.TryGetFeature<IActivatableLifetime>	#20617
Popup.PlacementMode	Popup.Placement	#20617
Screen.PixelDensity	Screen.Scaling	#20617
Screen.Primary	Screen.IsPrimary	#20617
ICompositionGpuImportedObject.ImportCompeted	ImportCompleted	#20613
IStyleable interface	StyledElement	#20613

Renamed members

Old name	New name	Notes	PR
PseudolassesExtensions	PseudoClassesExtensions	Typo fix. Most codebases are unaffected since this type is used implicitly from XAML or as C# extension methods.	#18717
X11PlatformOptions.ExterinalGLibMainLoopExceptionLogger	ExternalGLibMainLoopExceptionLogger	Typo fix.	#19128
TextBox.Watermark	TextBox.PlaceholderText	Old property kept as obsolete.	#20303
TextBox.UseFloatingWatermark	TextBox.UseFloatingPlaceholder	Old property kept as obsolete.	#20303
Window.SystemDecorations	Window.WindowDecorations	Old property kept as obsolete. See Window decoration changes.	#20796
RenderOptions.TextRenderingMode	TextOptions.TextRenderingMode	TextOptions also includes TextHintingMode and BaselinePixelAlignment. See Text options.	#20107
TextBlock.LetterSpacing	TextElement.LetterSpacing	Now an inherited attached property available on all templated controls. XAML on TextBlock is source-compatible; update code referencing TextBlock.LetterSpacingProperty to TextElement.LetterSpacingProperty.	#20141

See also

• Avalonia 12 release notes