[Android] Fix OnBackButtonPressed not invoked for Shell

src/Controls/src/Core/Compatibility/Handlers/Shell/Android/ShellToolbarTracker.cs

@@ -233,9 +233,13 @@ protected async virtual void OnNavigateBack()
 		{
 			try
 			{
-				// Call OnBackButtonPressed to allow the page to intercept navigation
-				if (Page?.SendBackButtonPressed() == true)
+				// Route through Shell.OnBackButtonPressed so that Shell subclass overrides
+				// are invoked consistently for both the navigation bar back button and the
+				// hardware/system back button (fixes dotnet/maui#9095).
+				if (_shell?.SendBackButtonPressed() == true)
+				{
 					return;
+				}
 
 				await Page.Navigation.PopAsync();
 			}

src/Controls/tests/TestCases.HostApp/Issues/Issue9095.cs

@@ -0,0 +1,162 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 9095,
+ "Shell toolbar back button doesn't fire Shell.OnBackButtonPressed on Android and iOS",
+ PlatformAffected.Android)]
+public class Issue9095 : TestShell
+{
+	internal static bool BackButtonPressedCalledReturnFalse;
+	internal static bool ContentPageBackButtonPressedCalledReturnFalse;
+
+	protected override void Init()
+	{
+		Routing.RegisterRoute(nameof(Issue9095SecondPage), typeof(Issue9095SecondPage));
+		Routing.RegisterRoute(nameof(Issue9095ReturnFalsePage), typeof(Issue9095ReturnFalsePage));
+		AddContentPage(new Issue9095RootPage());
+	}
+
+	protected override bool OnBackButtonPressed()
+	{
+		// Set static flag to prove Shell.OnBackButtonPressed was called
+		BackButtonPressedCalledReturnFalse = true;
+
+		if (CurrentPage is Issue9095SecondPage secondPage)
+		{
+			secondPage.UpdateStatus("OnBackButtonPressed Called");
+		}
+
+		// Delegate to base which calls ContentPage.OnBackButtonPressed internally.
+		// If ContentPage returns true → base returns true (navigation blocked).
+		// If ContentPage returns false → base pops the stack (navigation proceeds).
+		return base.OnBackButtonPressed();
+	}
+
+
+	public class Issue9095RootPage : ContentPage
+	{
+		readonly Label _returnFalseStatusLabel;
+		readonly Label _contentPageReturnFalseStatusLabel;
+
+		public Issue9095RootPage()
+		{
+			Title = "HomePage";
+			BackButtonPressedCalledReturnFalse = false;
+			ContentPageBackButtonPressedCalledReturnFalse = false;
+
+			var navigateButton = new Button
+			{
+				Text = "Go to Second Page",
+				AutomationId = "NavigateButton"
+			};
+
+			navigateButton.Clicked += async (s, e) =>
+			 await Shell.Current.GoToAsync(nameof(Issue9095SecondPage));
+
+			var navigateReturnFalseButton = new Button
+			{
+				Text = "Go to Return False Page",
+				AutomationId = "NavigateReturnFalseButton"
+			};
+
+			navigateReturnFalseButton.Clicked += async (s, e) =>
+			 await Shell.Current.GoToAsync(nameof(Issue9095ReturnFalsePage));
+
+			_returnFalseStatusLabel = new Label
+			{
+				Text = "Waiting",
+				AutomationId = "ReturnFalseStatusLabel"
+			};
+
+			_contentPageReturnFalseStatusLabel = new Label
+			{
+				Text = "Waiting",
+				AutomationId = "ContentPageReturnFalseStatusLabel"
+			};
+
+			Content = new VerticalStackLayout
+			{
+				Children = { navigateButton, navigateReturnFalseButton, _returnFalseStatusLabel, _contentPageReturnFalseStatusLabel }
+			};
+		}
+
+		protected override void OnAppearing()
+		{
+			base.OnAppearing();
+			if (BackButtonPressedCalledReturnFalse)
+			{
+				_returnFalseStatusLabel.Text = "OnBackButtonPressed Called And Returned False";
+				BackButtonPressedCalledReturnFalse = false;
+			}
+			if (ContentPageBackButtonPressedCalledReturnFalse)
+			{
+				_contentPageReturnFalseStatusLabel.Text = "ContentPage OnBackButtonPressed Called And Returned False";
+				ContentPageBackButtonPressedCalledReturnFalse = false;
+			}
+		}
+	}
+
+	public class Issue9095SecondPage : ContentPage
+	{
+		readonly Label _statusLabel;
+		readonly Label _contentPageStatusLabel;
+
+		public Issue9095SecondPage()
+		{
+			Title = "Second Page";
+
+			_statusLabel = new Label
+			{
+				Text = "OnBackButtonPressed Not Called",
+				AutomationId = "BackButtonPressedLabel"
+			};
+
+			_contentPageStatusLabel = new Label
+			{
+				Text = "ContentPage OnBackButtonPressed Not Called",
+				AutomationId = "ContentPageBackButtonLabel"
+			};
+
+			Content = new VerticalStackLayout
+			{
+				Children = { _statusLabel, _contentPageStatusLabel }
+			};
+		}
+
+		public void UpdateStatus(string text)
+		{
+			_statusLabel.Text = text;
+		}
+
+		protected override bool OnBackButtonPressed()
+		{
+			_contentPageStatusLabel.Text = "ContentPage OnBackButtonPressed Called";
+			return true;
+		}
+	}
+
+	public class Issue9095ReturnFalsePage : ContentPage
+	{
+		public Issue9095ReturnFalsePage()
+		{
+			Title = "Return False Page";
+
+			Content = new VerticalStackLayout
+			{
+				Children =
+	{
+	 new Label
+	 {
+	  Text = "Press back to test OnBackButtonPressed returning false",
+	  AutomationId = "ReturnFalsePageLabel"
+	 }
+	}
+			};
+		}
+
+		protected override bool OnBackButtonPressed()
+		{
+			ContentPageBackButtonPressedCalledReturnFalse = true;
+			return false;
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue9095.cs

@@ -0,0 +1,83 @@
+#if ANDROID // iOS/Mac fix pending in https://github.com/dotnet/maui/pull/35072
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue9095 : _IssuesUITest
+{
+	public Issue9095(TestDevice device) : base(device) { }
+
+	public override string Issue => "Shell toolbar back button doesn't fire Shell.OnBackButtonPressed on Android and iOS";
+
+	protected override bool ResetAfterEachTest => true;
+
+	[Test]
+	[Category(UITestCategories.Shell)]
+	public void ShellOnBackButtonPressedShouldBeInvokedWhenPressingNavigationBarBackButton()
+	{
+		// Navigate to the second page
+		App.WaitForElement("NavigateButton");
+		App.Tap("NavigateButton");
+
+		// Wait for the second page to appear
+		App.WaitForElement("BackButtonPressedLabel");
+
+		// Verify the initial state
+		var initialText = App.FindElement("BackButtonPressedLabel").GetText();
+		Assert.That(initialText, Is.EqualTo("OnBackButtonPressed Not Called"),
+		 "Label should show 'Not Called' before pressing back.");
+
+		var initialContentPageText = App.FindElement("ContentPageBackButtonLabel").GetText();
+		Assert.That(initialContentPageText, Is.EqualTo("ContentPage OnBackButtonPressed Not Called"),
+		 "ContentPage label should show 'Not Called' before pressing back.");
+
+		// Tap the Shell toolbar back button
+		if (App is AppiumIOSApp iosApp && HelperExtensions.IsIOS26OrHigher(iosApp))
+			App.TapBackArrow(); // iOS 26+ doesn't show the previous page title in the back button
+		else
+			App.TapBackArrow(Device is TestDevice.iOS or TestDevice.Mac ? "HomePage" : "");
+
+		// Shell.OnBackButtonPressed should have been called, updating the label.
+		// The second page remains visible because Shell.OnBackButtonPressed returns true.
+		var updatedText = App.WaitForElement("BackButtonPressedLabel").GetText();
+		Assert.That(updatedText, Is.EqualTo("OnBackButtonPressed Called"),
+		 "Shell.OnBackButtonPressed should be invoked when pressing the Shell toolbar back button.");
+
+		// ContentPage.OnBackButtonPressed should also have been called.
+		var contentPageText = App.FindElement("ContentPageBackButtonLabel").GetText();
+		Assert.That(contentPageText, Is.EqualTo("ContentPage OnBackButtonPressed Called"),
+		 "ContentPage.OnBackButtonPressed should be invoked when pressing the Shell toolbar back button.");
+	}
+
+	[Test]
+	[Category(UITestCategories.Shell)]
+	public void ShellOnBackButtonPressedReturnFalseShouldNavigateBack()
+	{
+		// Navigate to the return-false page
+		App.WaitForElement("NavigateReturnFalseButton");
+		App.Tap("NavigateReturnFalseButton");
+
+		// Wait for the return-false page to appear
+		App.WaitForElement("ReturnFalsePageLabel");
+
+		// Tap the Shell toolbar back button
+		if (App is AppiumIOSApp iosApp && HelperExtensions.IsIOS26OrHigher(iosApp))
+			App.TapBackArrow();
+		else
+			App.TapBackArrow(Device is TestDevice.iOS or TestDevice.Mac ? "HomePage" : "");
+
+		// Shell.OnBackButtonPressed returned false, so navigation should proceed back to root.
+		// The labels on the root page confirm both Shell and ContentPage OnBackButtonPressed were called.
+		App.WaitForElement("ReturnFalseStatusLabel");
+		var shellStatusText = App.FindElement("ReturnFalseStatusLabel").GetText();
+		Assert.That(shellStatusText, Is.EqualTo("OnBackButtonPressed Called And Returned False"),
+		 "Shell.OnBackButtonPressed should have been called even when returning false.");
+
+		var contentPageStatusText = App.FindElement("ContentPageReturnFalseStatusLabel").GetText();
+		Assert.That(contentPageStatusText, Is.EqualTo("ContentPage OnBackButtonPressed Called And Returned False"),
+		 "ContentPage.OnBackButtonPressed should have been called even when returning false.");
+	}
+}
+#endif