[Android, Windows] Fix CollectionView handler cleanup when DataTemplateSelector switches templates

src/Controls/src/Core/Handlers/Items/Android/ItemContentView.cs

@@ -66,6 +66,10 @@ internal void Recycle()
 				RemoveView(platformView);
 			}
 
+			// Capture the current platform view before disconnecting handlers, because
+			// DisconnectHandlers() may null out the handler's PlatformView/ContainerView.
+			View?.DisconnectHandlers();
+
 			Content = null;
 			_pixelSize = null;
 			_reportMeasure = null;

src/Controls/src/Core/Handlers/Items/Android/TemplatedItemViewHolder.cs

@@ -42,6 +42,14 @@ public void Recycle(ItemsView itemsView)
 			}
 
 			itemsView.RemoveLogicalChild(View);
+
+			// Disconnect and clear the handler via ItemContentView.Recycle(), which calls
+			// DisconnectHandlers() before releasing Content. Reset _selectedTemplate so the
+			// next Bind() call always goes through the templateChanging path and recreates
+			// the handler (since we just disconnected it).
+			_itemContentView.Recycle();
+			View = null; // clear reference to the disconnected view
+			_selectedTemplate = null; // force templateChanging=true on next Bind() to recreate the view
 		}
 
 		public void Bind(object itemBindingContext, ItemsView itemsView,

src/Controls/src/Core/Handlers/Items/ItemsViewHandler.Windows.cs

@@ -184,7 +184,12 @@ private void CleanUpCollectionViewSource(ListViewBase platformView)
 				foreach (var item in platformView.GetChildren<ItemContentControl>())
 				{
 					var element = item.GetVisualElement();
-					VirtualView.RemoveLogicalChild(element);
+
+					if (element is not null)
+					{
+						element.DisconnectHandlers();
+						VirtualView.RemoveLogicalChild(element);
+					}
 				}
 			}
 

src/Controls/tests/TestCases.HostApp/Issues/Issue32243.cs

@@ -0,0 +1,315 @@
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 32243, "CollectionView does not disconnect handlers when DataTemplateSelector changes template", PlatformAffected.Android | PlatformAffected.UWP)]
+public class Issue32243 : NavigationPage
+{
+	public Issue32243() : base(new _Issue32243MainPage())
+	{
+		_Issue32243TrackingLabel.ResetAll();
+	}
+}
+
+class _Issue32243MainPage : ContentPage
+{
+	readonly Label _handlerCountLabel;
+	readonly Label _statusLabel;
+
+	public _Issue32243MainPage()
+	{
+		Title = "Issue 32243";
+
+		_statusLabel = new Label
+		{
+			Text = "Navigate to the CollectionView page, switch templates, go back, then check handlers.",
+			AutomationId = "StatusLabel"
+		};
+
+		_handlerCountLabel = new Label
+		{
+			Text = "Connected handlers will be shown here.",
+			AutomationId = "HandlerCountLabel"
+		};
+
+		var navigateButton = new Button
+		{
+			Text = "Navigate to template page",
+			AutomationId = "NavigateButton"
+		};
+
+		navigateButton.Clicked += async (sender, args) =>
+		{
+			await Navigation.PushAsync(new _Issue32243CollectionPage());
+		};
+
+		var checkHandlersButton = new Button
+		{
+			Text = "Show connected handlers",
+			AutomationId = "CheckHandlersButton"
+		};
+
+		checkHandlersButton.Clicked += (sender, args) =>
+		{
+			var labelsWithHandlers = _Issue32243TrackingLabel.GetLabelsWithConnectedHandlers();
+
+			if (labelsWithHandlers.Count == 0)
+			{
+				_handlerCountLabel.Text = "✓ No labels have connected handlers (all cleaned up!)";
+				_handlerCountLabel.TextColor = Colors.Green;
+				_statusLabel.Text = "Status: No connected handlers found.";
+			}
+			else
+			{
+				var details = string.Join("\n", labelsWithHandlers.Select(label =>
+					$"Label #{label.InstanceId} - Text: '{label.Text}'"));
+
+				_handlerCountLabel.Text = $"⚠️ {labelsWithHandlers.Count} labels still have connected handlers:\n{details}";
+				_handlerCountLabel.TextColor = Colors.Brown;
+				_statusLabel.Text = "Status: Connected handlers are still present.";
+			}
+		};
+
+		Content = new VerticalStackLayout
+		{
+			Padding = 20,
+			Spacing = 10,
+			Children =
+			{
+				new Label
+				{
+					Text = "This test mirrors the sandbox flow: navigate, switch templates, navigate back, then verify disconnected handlers."
+				},
+				navigateButton,
+				checkHandlersButton,
+				_statusLabel,
+				_handlerCountLabel
+			}
+		};
+	}
+}
+
+class _Issue32243CollectionPage : ContentPage
+{
+	readonly List<_Issue32243Item> _items;
+	readonly CollectionView _collectionView;
+	readonly Label _statusLabel;
+
+	public _Issue32243CollectionPage()
+	{
+		Title = "Template Page";
+
+		_items = Enumerable.Range(1, 50).Select(i => new _Issue32243Item
+		{
+			Name = $"Item {i}",
+			UseTemplateA = i % 2 == 1
+		}).ToList();
+
+		var templateA = new DataTemplate(() =>
+		{
+			var label = new _Issue32243TrackingLabel();
+			label.SetBinding(Label.TextProperty, nameof(_Issue32243Item.Name));
+			return new VerticalStackLayout
+			{
+				BackgroundColor = Colors.LightBlue,
+				Padding = new Thickness(10),
+				Children =
+				{
+					label,
+					new Label { Text = "Template A", TextColor = Colors.Blue }
+				}
+			};
+		});
+
+		var templateB = new DataTemplate(() =>
+		{
+			var label = new Label();
+			label.SetBinding(Label.TextProperty, nameof(_Issue32243Item.Name));
+			return new VerticalStackLayout
+			{
+				BackgroundColor = Colors.LightGray,
+				Padding = new Thickness(10),
+				Children =
+				{
+					label,
+					new Label { Text = "Template B", TextColor = Colors.Gray }
+				}
+			};
+		});
+
+		_statusLabel = new Label
+		{
+			Text = "Status: Mixed templates active",
+			AutomationId = "TemplatePageStatusLabel"
+		};
+
+		var switchTemplateButton = new Button
+		{
+			Text = "Switch to all Template B",
+			AutomationId = "SwitchTemplateButton"
+		};
+
+		switchTemplateButton.Clicked += (sender, args) =>
+		{
+			foreach (var item in _items)
+			{
+				item.UseTemplateA = false;
+			}
+
+			_collectionView.ItemsSource = _items.ToList();
+			_statusLabel.Text = "Status: All items using Template B";
+		};
+
+		var navigateBackButton = new Button
+		{
+			Text = "Navigate back",
+			AutomationId = "NavigateBackButton"
+		};
+
+		navigateBackButton.Clicked += async (sender, args) =>
+		{
+			await Navigation.PopAsync();
+		};
+
+		_collectionView = new CollectionView
+		{
+			AutomationId = "ItemsCollectionView",
+			SelectionMode = SelectionMode.None,
+			ItemTemplate = new _Issue32243TemplateSelector
+			{
+				TemplateA = templateA,
+				TemplateB = templateB
+			},
+			ItemsSource = _items
+		};
+
+		Content = new Grid
+		{
+			RowDefinitions =
+			{
+				new RowDefinition { Height = GridLength.Auto },
+				new RowDefinition { Height = GridLength.Star }
+			},
+			Children =
+			{
+				new VerticalStackLayout
+				{
+					Padding = new Thickness(20, 20, 20, 10),
+					Spacing = 8,
+					Children =
+					{
+						new Label { Text = "50 items — odd=Template A (blue), even=Template B (gray)" },
+						switchTemplateButton,
+						navigateBackButton,
+						_statusLabel
+					}
+				},
+				_collectionView
+			}
+		};
+
+		Grid.SetRow(_collectionView, 1);
+	}
+}
+
+class _Issue32243TrackingLabel : Label
+{
+	static int _instanceCounter;
+	static readonly List<WeakReference<_Issue32243TrackingLabel>> _allInstances = [];
+	readonly int _instanceId;
+
+	public _Issue32243TrackingLabel()
+	{
+		_instanceId = ++_instanceCounter;
+		_allInstances.Add(new WeakReference<_Issue32243TrackingLabel>(this));
+		DeviceDisplay.MainDisplayInfoChanged += OnMainDisplayInfoChanged;
+	}
+
+	protected override void OnHandlerChanged()
+	{
+		base.OnHandlerChanged();
+
+		if (Handler is null)
+		{
+			DeviceDisplay.MainDisplayInfoChanged -= OnMainDisplayInfoChanged;
+		}
+	}
+
+	public int InstanceId => _instanceId;
+
+	public static List<_Issue32243TrackingLabel> GetLabelsWithConnectedHandlers()
+	{
+		var result = new List<_Issue32243TrackingLabel>();
+
+		_allInstances.RemoveAll(wr =>
+		{
+			if (wr.TryGetTarget(out var label))
+			{
+				if (label.Handler != null)
+				{
+					result.Add(label);
+				}
+
+				return false;
+			}
+
+			return true;
+		});
+
+		return result;
+	}
+
+	void OnMainDisplayInfoChanged(object sender, DisplayInfoChangedEventArgs e)
+	{
+		_ = _instanceId;
+	}
+
+	public static void ResetAll()
+	{
+		_allInstances.Clear();
+		_instanceCounter = 0;
+	}
+}
+
+class _Issue32243TemplateSelector : DataTemplateSelector
+{
+	public DataTemplate TemplateA { get; set; }
+	public DataTemplate TemplateB { get; set; }
+
+	protected override DataTemplate OnSelectTemplate(object item, BindableObject container)
+	{
+		return item is _Issue32243Item { UseTemplateA: true } ? TemplateA : TemplateB;
+	}
+}
+
+class _Issue32243Item : INotifyPropertyChanged
+{
+	string _name = string.Empty;
+	bool _useTemplateA;
+
+	public string Name
+	{
+		get => _name;
+		set
+		{
+			_name = value;
+			OnPropertyChanged();
+		}
+	}
+
+	public bool UseTemplateA
+	{
+		get => _useTemplateA;
+		set
+		{
+			_useTemplateA = value;
+			OnPropertyChanged();
+		}
+	}
+
+	public event PropertyChangedEventHandler PropertyChanged;
+
+	protected void OnPropertyChanged([CallerMemberName] string name = null)
+		=> PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue32243.cs

@@ -0,0 +1,33 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+[Category(UITestCategories.CollectionView)]
+public class Issue32243 : _IssuesUITest
+{
+	public Issue32243(TestDevice testDevice) : base(testDevice) { }
+
+	public override string Issue => "CollectionView does not disconnect handlers when DataTemplateSelector changes template";
+
+	[Test]
+	public void CollectionViewDisconnectsHandlersAfterNavigationBack()
+	{
+		App.WaitForElement("NavigateButton");
+		App.Tap("NavigateButton");
+
+		App.WaitForElement("SwitchTemplateButton");
+		App.Tap("SwitchTemplateButton");
+
+		App.WaitForElement("NavigateBackButton");
+		App.Tap("NavigateBackButton");
+
+		App.WaitForElement("CheckHandlersButton");
+		App.Tap("CheckHandlersButton");
+
+		var result = App.WaitForElement("HandlerCountLabel").GetText();
+		Assert.That(result, Is.EqualTo("✓ No labels have connected handlers (all cleaned up!)"),
+			"CollectionView should disconnect handlers from views belonging to the old DataTemplate after navigating back.");
+	}
+}