feat: Support for ComboBox.SelectionChangedTrigger

src/Uno.UI/Generated/3.0.0.0/Microsoft.UI.Xaml.Controls/ComboBox.cs

@@ -36,7 +36,7 @@ public string Text
 			}
 		}
 #endif
-#if __ANDROID__ || __IOS__ || IS_UNIT_TESTS || __WASM__ || __SKIA__ || __NETSTD_REFERENCE__ || __MACOS__
+#if false
 		[global::Uno.NotImplemented("__ANDROID__", "__IOS__", "IS_UNIT_TESTS", "__WASM__", "__SKIA__", "__NETSTD_REFERENCE__", "__MACOS__")]
 		public global::Microsoft.UI.Xaml.Controls.ComboBoxSelectionChangedTrigger SelectionChangedTrigger
 		{
@@ -141,7 +141,7 @@ public object SelectionBoxItem
 			new Microsoft.UI.Xaml.FrameworkPropertyMetadata(default(global::Microsoft.UI.Xaml.Media.Brush)));
 #endif
 		// Skipping already declared property PlaceholderTextProperty
-#if __ANDROID__ || __IOS__ || IS_UNIT_TESTS || __WASM__ || __SKIA__ || __NETSTD_REFERENCE__ || __MACOS__
+#if false
 		[global::Uno.NotImplemented("__ANDROID__", "__IOS__", "IS_UNIT_TESTS", "__WASM__", "__SKIA__", "__NETSTD_REFERENCE__", "__MACOS__")]
 		public static global::Microsoft.UI.Xaml.DependencyProperty SelectionChangedTriggerProperty { get; } =
 		Microsoft.UI.Xaml.DependencyProperty.Register(

src/Uno.UI/Generated/3.0.0.0/Microsoft.UI.Xaml.Controls/ComboBoxSelectionChangedTrigger.cs

@@ -3,7 +3,7 @@
 #pragma warning disable 114 // new keyword hiding
 namespace Microsoft.UI.Xaml.Controls
 {
-#if __ANDROID__ || __IOS__ || IS_UNIT_TESTS || __WASM__ || __SKIA__ || __NETSTD_REFERENCE__ || __MACOS__
+#if false
 	public enum ComboBoxSelectionChangedTrigger
 	{
 #if __ANDROID__ || __IOS__ || IS_UNIT_TESTS || __WASM__ || __SKIA__ || __NETSTD_REFERENCE__ || __MACOS__

src/Uno.UI/UI/Xaml/Controls/ComboBox/ComboBox.Properties.cs

@@ -183,6 +183,22 @@ public Brush PlaceholderForeground
 	/// </summary>
 	public DataTemplate SelectionBoxItemTemplate { get; private set; }
 
+	/// <summary>
+	/// Gets or sets a value that indicates what action causes a SelectionChanged event to occur.
+	/// </summary>
+	public ComboBoxSelectionChangedTrigger SelectionChangedTrigger
+	{
+		get => (ComboBoxSelectionChangedTrigger)GetValue(SelectionChangedTriggerProperty);
+		set => SetValue(SelectionChangedTriggerProperty, value);
+	}
+
+	public static DependencyProperty SelectionChangedTriggerProperty { get; } =
+		DependencyProperty.Register(
+			nameof(SelectionChangedTrigger),
+			typeof(ComboBoxSelectionChangedTrigger),
+			typeof(ComboBox),
+			new FrameworkPropertyMetadata(default(ComboBoxSelectionChangedTrigger)));
+
 	/// <summary>
 	/// Gets an object that provides calculated values that can be referenced
 	/// as TemplateBinding sources when defining templates for a ComboBox control.

src/Uno.UI/UI/Xaml/Controls/ComboBox/ComboBoxSelectionChangedTrigger.cs

@@ -0,0 +1,17 @@
+namespace Microsoft.UI.Xaml.Controls;
+
+/// <summary>
+/// Defines constants that specify what action causes a SelectionChanged event to occur.
+/// </summary>
+public enum ComboBoxSelectionChangedTrigger
+{
+	/// <summary>
+	/// A change event occurs when the user commits a selection in the combo box.
+	/// </summary>
+	Committed = 0,
+
+	/// <summary>
+	/// A change event occurs each time the user navigates to a new selection in the combo box.
+	/// </summary>
+	Always = 1,
+}