Fix erratic Page.Loaded events in Shell tab navigation

src/Controls/src/Core/Shell/ShellContent.cs

@@ -244,6 +244,35 @@ shellSection.Parent is ShellItem shellItem &&
 					this.Window is null; // user has set the main page to a different shell instance
 			}
 
+			// Additional check: Don't disconnect if we're just switching between tabs in the same section
+			// This prevents unnecessary page recreation and multiple Loaded events
+			// Fixes: https://github.com/dotnet/maui/issues/11
+			if (disconnect && Parent is ShellSection currentSection && 
+			    currentSection.Parent is ShellItem currentItem && 
+			    shell?.CurrentItem == currentItem)
+			{
+				// We're still within the same ShellItem, just switching tabs
+				// Only disconnect if this specific ShellContent is not the current one
+				// and it's not adjacent to the current one (to allow for smooth tab transitions)
+				if (currentSection.CurrentItem == this)
+				{
+					disconnect = false;
+				}
+				else
+				{
+					var items = currentSection.Items;
+					var currentIndex = items.IndexOf(currentSection.CurrentItem);
+					var thisIndex = items.IndexOf(this);
+
+					// Keep adjacent tabs loaded to allow for smooth transitions and swipe gestures
+					// This prevents the erratic Page.Loaded events described in the issue
+					if (currentIndex >= 0 && thisIndex >= 0 && Math.Abs(currentIndex - thisIndex) <= 1)
+					{
+						disconnect = false;
+					}
+				}
+			}
+
 			if (!disconnect)
 			{
 				shell?.NotifyFlyoutBehaviorObservers();

src/Controls/src/Core/VisualElement/VisualElement.Platform.cs

@@ -16,6 +16,7 @@ namespace Microsoft.Maui.Controls
 	public partial class VisualElement
 	{
 		IDisposable? _loadedUnloadedToken;
+
 		partial void HandlePlatformUnloadedLoaded()
 		{
 			_loadedUnloadedToken?.Dispose();
@@ -27,7 +28,20 @@ partial void HandlePlatformUnloadedLoaded()
 			{
 				if (view.IsLoaded())
 				{
+#if ANDROID
+					// Android-specific: Only send Loaded if this is a genuinely new platform view
+					// or if we haven't fired Loaded for this view yet. This prevents multiple
+					// Loaded events during Shell fragment lifecycle changes.
+					bool shouldSendLoaded = _lastPlatformView != view || !_isLoadedFired;
+					_lastPlatformView = view;
+
+					if (shouldSendLoaded)
+					{
+						SendLoaded(false);
+					}
+#else
 					SendLoaded(false);
+#endif
 
 					// If SendLoaded caused the unloaded tokens to wire up
 					_loadedUnloadedToken?.Dispose();
@@ -57,6 +71,10 @@ partial void HandlePlatformUnloadedLoaded()
 				}
 				else
 				{
+#if ANDROID
+					// Android-specific: Clear the tracked platform view when unloading
+					_lastPlatformView = null;
+#endif
 					SendUnloaded();
 				}
 			}

src/Controls/src/Core/VisualElement/VisualElement.cs

@@ -1785,6 +1785,11 @@ void UpdateBoundsComponents(Rect bounds)
 		EventHandler? _loaded;
 		EventHandler? _unloaded;
 		bool _watchingPlatformLoaded;
+#if ANDROID
+		// Android-specific: Track the last platform view to prevent redundant Loaded events
+		// during Shell fragment lifecycle changes
+		object? _lastPlatformView;
+#endif
 		Rect _frame = new Rect(0, 0, -1, -1);
 		event EventHandler? _windowChanged;
 		event EventHandler? _platformContainerViewChanged;
@@ -1819,6 +1824,11 @@ private protected override void OnHandlerChangedCore()
 			base.OnHandlerChangedCore();
 
 			IsPlatformEnabled = Handler != null;
+#if ANDROID
+			// Android-specific: Reset tracked platform view when handler changes
+			// to ensure proper Loaded event handling with new platform views
+			_lastPlatformView = null;
+#endif
 			UpdatePlatformUnloadedLoadedWiring(Window);
 		}
 

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

@@ -0,0 +1,217 @@
+using System;
+using System.Collections.Generic;
+using Microsoft.Maui.Controls;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[Issue(IssueTracker.Github, 11, "For pages used in FlyoutItem/Tab/ShellContent the Page.Loaded event is called erratically", PlatformAffected.All)]
+	public class ShellPageLoadedIssue : Shell
+	{
+		public static Dictionary<string, int> PageLoadedCounts = new Dictionary<string, int>();
+		public static Dictionary<string, List<string>> LoadedPageSequence = new Dictionary<string, List<string>>();
+		public static string CurrentTestName = "";
+
+		public ShellPageLoadedIssue()
+		{
+			var tab = new Tab { Title = "The Pages", Route = "ViewCaseViewModel" };
+
+			tab.Items.Add(new ShellContent
+			{
+				Title = "Main Page",
+				ContentTemplate = new DataTemplate(() => new TestPage1()),
+				Route = "Route1"
+			});
+
+			tab.Items.Add(new ShellContent
+			{
+				Title = "Other Page", 
+				ContentTemplate = new DataTemplate(() => new TestPage2()),
+				Route = "Route2"
+			});
+
+			tab.Items.Add(new ShellContent
+			{
+				Title = "Another Page",
+				ContentTemplate = new DataTemplate(() => new TestPage3()),
+				Route = "Route3"
+			});
+
+			var flyoutItem = new FlyoutItem
+			{
+				FlyoutDisplayOptions = FlyoutDisplayOptions.AsMultipleItems
+			};
+			flyoutItem.Items.Add(tab);
+
+			this.Items.Add(flyoutItem);
+
+			// Add single shell contents
+			this.Items.Add(new ShellContent
+			{
+				Title = "Single Main",
+				ContentTemplate = new DataTemplate(() => new TestPage1()),
+				Route = "MainPage"
+			});
+
+			this.Items.Add(new ShellContent
+			{
+				Title = "Single Other",
+				ContentTemplate = new DataTemplate(() => new TestPage2()),
+				Route = "OtherPage"
+			});
+		}
+
+		public static void ResetCounters(string testName)
+		{
+			CurrentTestName = testName;
+			PageLoadedCounts.Clear();
+			if (!LoadedPageSequence.ContainsKey(testName))
+				LoadedPageSequence[testName] = new List<string>();
+			else
+				LoadedPageSequence[testName].Clear();
+		}
+
+		public static void RecordPageLoaded(string pageName)
+		{
+			if (!PageLoadedCounts.ContainsKey(pageName))
+				PageLoadedCounts[pageName] = 0;
+
+			PageLoadedCounts[pageName]++;
+
+			if (!string.IsNullOrEmpty(CurrentTestName))
+			{
+				if (!LoadedPageSequence.ContainsKey(CurrentTestName))
+					LoadedPageSequence[CurrentTestName] = new List<string>();
+				LoadedPageSequence[CurrentTestName].Add($"{pageName}:{PageLoadedCounts[pageName]}");
+			}
+		}
+	}
+
+	public class TestPage1 : ContentPage
+	{
+		public TestPage1()
+		{
+			Title = "Main Page";
+			AutomationId = "TestPage1";
+			Content = new StackLayout
+			{
+				Children =
+				{
+					new Label { Text = "This is Test Page 1", AutomationId = "Page1Label" },
+					new Button 
+					{ 
+						Text = "Navigate to Other Page", 
+						AutomationId = "NavigateToOtherButton",
+						Command = new Command(async () => await Shell.Current.GoToAsync("//Route2"))
+					},
+					new Button 
+					{ 
+						Text = "Navigate to Another Page", 
+						AutomationId = "NavigateToAnotherButton",
+						Command = new Command(async () => await Shell.Current.GoToAsync("//Route3"))
+					},
+					new Label { Text = GetLoadedCountText(), AutomationId = "LoadedCountLabel" }
+				}
+			};
+
+			this.Loaded += (s, e) => 
+			{
+				ShellPageLoadedIssue.RecordPageLoaded("TestPage1");
+				if (Content is StackLayout stack && stack.Children.Last() is Label label)
+				{
+					label.Text = GetLoadedCountText();
+				}
+			};
+		}
+
+		private string GetLoadedCountText()
+		{
+			return $"Page1 Loaded Count: {(ShellPageLoadedIssue.PageLoadedCounts.ContainsKey("TestPage1") ? ShellPageLoadedIssue.PageLoadedCounts["TestPage1"] : 0)}";
+		}
+	}
+
+	public class TestPage2 : ContentPage
+	{
+		public TestPage2()
+		{
+			Title = "Other Page";
+			AutomationId = "TestPage2";
+			Content = new StackLayout
+			{
+				Children =
+				{
+					new Label { Text = "This is Test Page 2", AutomationId = "Page2Label" },
+					new Button 
+					{ 
+						Text = "Navigate to Main Page", 
+						AutomationId = "NavigateToMainButton",
+						Command = new Command(async () => await Shell.Current.GoToAsync("//Route1"))
+					},
+					new Button 
+					{ 
+						Text = "Navigate to Another Page", 
+						AutomationId = "NavigateToAnotherButton",
+						Command = new Command(async () => await Shell.Current.GoToAsync("//Route3"))
+					},
+					new Label { Text = GetLoadedCountText(), AutomationId = "LoadedCountLabel" }
+				}
+			};
+
+			this.Loaded += (s, e) => 
+			{
+				ShellPageLoadedIssue.RecordPageLoaded("TestPage2");
+				if (Content is StackLayout stack && stack.Children.Last() is Label label)
+				{
+					label.Text = GetLoadedCountText();
+				}
+			};
+		}
+
+		private string GetLoadedCountText()
+		{
+			return $"Page2 Loaded Count: {(ShellPageLoadedIssue.PageLoadedCounts.ContainsKey("TestPage2") ? ShellPageLoadedIssue.PageLoadedCounts["TestPage2"] : 0)}";
+		}
+	}
+
+	public class TestPage3 : ContentPage
+	{
+		public TestPage3()
+		{
+			Title = "Another Page";
+			AutomationId = "TestPage3";
+			Content = new StackLayout
+			{
+				Children =
+				{
+					new Label { Text = "This is Test Page 3", AutomationId = "Page3Label" },
+					new Button 
+					{ 
+						Text = "Navigate to Main Page", 
+						AutomationId = "NavigateToMainButton",
+						Command = new Command(async () => await Shell.Current.GoToAsync("//Route1"))
+					},
+					new Button 
+					{ 
+						Text = "Navigate to Other Page", 
+						AutomationId = "NavigateToOtherButton",
+						Command = new Command(async () => await Shell.Current.GoToAsync("//Route2"))
+					},
+					new Label { Text = GetLoadedCountText(), AutomationId = "LoadedCountLabel" }
+				}
+			};
+
+			this.Loaded += (s, e) => 
+			{
+				ShellPageLoadedIssue.RecordPageLoaded("TestPage3");
+				if (Content is StackLayout stack && stack.Children.Last() is Label label)
+				{
+					label.Text = GetLoadedCountText();
+				}
+			};
+		}
+
+		private string GetLoadedCountText()
+		{
+			return $"Page3 Loaded Count: {(ShellPageLoadedIssue.PageLoadedCounts.ContainsKey("TestPage3") ? ShellPageLoadedIssue.PageLoadedCounts["TestPage3"] : 0)}";
+		}
+	}
+}