[Windows] Notify Shell tab title changes

src/Controls/src/Core/Handlers/Shell/ShellItemHandler.Windows.cs

@@ -16,6 +16,7 @@ public partial class ShellItemHandler : ElementHandler<ShellItem, FrameworkEleme
 		public static PropertyMapper<ShellItem, ShellItemHandler> Mapper =
 				new PropertyMapper<ShellItem, ShellItemHandler>(ElementMapper)
 				{
+					[nameof(ShellItem.Title)] = MapTitle,
 					[nameof(ShellItem.CurrentItem)] = MapCurrentItem,
 					[Shell.TabBarIsVisibleProperty.PropertyName] = MapTabBarIsVisible
 				};
@@ -352,6 +353,12 @@ void UpdateQueryIcon()
 		}
 
 		ShellSection? _currentShellSection;
+
+		internal void UpdateTitle()
+		{
+			MapMenuItems();
+		}
+
 		void UpdateCurrentItem()
 		{
 			if (_currentShellSection == VirtualView.CurrentItem)
@@ -433,6 +440,11 @@ NavigationViewPaneDisplayMode GetNavigationViewPaneDisplayMode(IShellItemControl
 				NavigationViewPaneDisplayMode.LeftMinimal;
 		}
 
+		public static void MapTitle(ShellItemHandler handler, ShellItem item)
+		{
+			handler.UpdateTitle();
+		}
+
 		public static void MapCurrentItem(ShellItemHandler handler, ShellItem item)
 		{
 			handler.UpdateCurrentItem();

src/Controls/src/Core/Handlers/Shell/ShellSectionHandler.Windows.cs

@@ -12,6 +12,7 @@ public partial class ShellSectionHandler : ElementHandler<ShellSection, WFrame>,
 		public static PropertyMapper<ShellSection, ShellSectionHandler> Mapper =
 				new PropertyMapper<ShellSection, ShellSectionHandler>(ElementMapper)
 				{
+					[nameof(ShellSection.Title)] = MapTitle,
 					[nameof(ShellSection.CurrentItem)] = MapCurrentItem,
 				};
 
@@ -34,7 +35,13 @@ protected override WFrame CreatePlatformElement()
 			_navigationManager = CreateNavigationManager();
 			return new WFrame();
 		}
-
+		public static void MapTitle(ShellSectionHandler handler, ShellSection item)
+		{		
+			var shellItem = item.Parent as ShellItem;
+			var shellItemHandler = shellItem?.Handler as ShellItemHandler;
+			shellItemHandler?.UpdateTitle();
+		}
+
 		public static void MapCurrentItem(ShellSectionHandler handler, ShellSection item)
 		{
 			handler.SyncNavigationStack(false, null);

src/Controls/src/Core/PublicAPI/net-windows/PublicAPI.Unshipped.txt

@@ -1,6 +1,8 @@
 #nullable enable
 *REMOVED*~Microsoft.Maui.Controls.Accelerator.Modifiers.set -> void
 *REMOVED*~Microsoft.Maui.Controls.Accelerator.Keys.set -> void
+static Microsoft.Maui.Controls.Handlers.ShellItemHandler.MapTitle(Microsoft.Maui.Controls.Handlers.ShellItemHandler! handler, Microsoft.Maui.Controls.ShellItem! item) -> void
+static Microsoft.Maui.Controls.Handlers.ShellSectionHandler.MapTitle(Microsoft.Maui.Controls.Handlers.ShellSectionHandler! handler, Microsoft.Maui.Controls.ShellSection! item) -> void
 Microsoft.Maui.Controls.PointerGestureRecognizer.PointerPressed -> System.EventHandler<Microsoft.Maui.Controls.PointerEventArgs!>?
 Microsoft.Maui.Controls.PointerGestureRecognizer.PointerPressedCommand.get -> System.Windows.Input.ICommand!
 Microsoft.Maui.Controls.PointerGestureRecognizer.PointerPressedCommand.set -> void

src/Controls/tests/DeviceTests/Elements/Shell/ShellTests.Windows.cs

@@ -11,6 +11,7 @@
 using Microsoft.Maui.Platform;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
+using Microsoft.Maui.DeviceTests.Stubs;
 using Xunit;
 using NavigationView = Microsoft.UI.Xaml.Controls.NavigationView;
 using WFrameworkElement = Microsoft.UI.Xaml.FrameworkElement;
@@ -28,6 +29,40 @@ protected Task CheckFlyoutState(ShellHandler handler, bool desiredState)
 			return Task.CompletedTask;
 		}
 
+		[Fact(DisplayName = "Shell Title Updates Correctly")]
+		public async Task ShellTitleUpdatesCorrectly()
+		{
+			SetupBuilder();
+
+			var page1 = new ContentPage()
+			{ Content = new Label() { Text = "Page 1" }, Title = "Page 1" };
+			var page2 = new ContentPage()
+			{ Content = new Label() { Text = "Page 2" }, Title = "Page 2" };
+
+			var shell = await CreateShellAsync((shell) =>
+			{
+				var tabBar = new TabBar()
+				{
+					Items =
+					{
+						new ShellContent(){ Content = page1 },
+						new ShellContent(){ Content = page2 },
+					}
+				};
+
+				shell.Items.Add(tabBar);
+			});
+
+			await CreateHandlerAndAddToWindow<WindowHandlerStub>(new Controls.Window(shell), (handler) =>
+			{
+				Assert.Equal("Page 1", GetToolbarTitle(handler));
+
+				string newTitle = "New Page 1";
+				page1.Title = newTitle;
+				Assert.Equal(newTitle, GetToolbarTitle(handler));
+			});
+		}
+
 		[Fact(DisplayName = "Shell FlyoutIcon Initializes Correctly")]
 		public async Task ShellFlyoutIconInitializesCorrectly()
 		{