[Android] Fixed removing items from grouped list

src/Controls/src/Core/Compatibility/Handlers/ListView/Android/ListViewAdapter.cs

@@ -329,6 +329,16 @@ public override AView GetView(int position, AView convertView, ViewGroup parent)
 				return layout;
 			}
 
+			bool isHeader = cell.GetIsGroupHeader<ItemsView<Cell>, Cell>();
+
+			if (isHeader)
+			{
+				// We need to re-render the header to ensure it is properly measured and laid out.
+				// This is necessary because headers often have different layouts and sizes compared to regular cells,
+				// and reusing a view for a header can result in incorrect measurements and layout issues.
+				convertView = null;
+			}
+
 			AView view = CellFactory.GetCell(cell, convertView, parent, _context, _listView);
 
 			Performance.Start(reference, "AddView");
@@ -337,6 +347,7 @@ public override AView GetView(int position, AView convertView, ViewGroup parent)
 			{
 				if (convertView != view)
 				{
+					view.RemoveFromParent();
 					layout.RemoveViewAt(0);
 					layout.AddView(view, 0);
 				}
@@ -351,8 +362,6 @@ public override AView GetView(int position, AView convertView, ViewGroup parent)
 
 			Performance.Stop(reference, "AddView");
 
-			bool isHeader = cell.GetIsGroupHeader<ItemsView<Cell>, Cell>();
-
 			AView bline;
 
 			bool isSeparatorVisible = _listView.SeparatorVisibility == SeparatorVisibility.Default;

src/Controls/tests/TestCases.HostApp/Issues/Issue26015.xaml

@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ContentPage
+    xmlns:controls="clr-namespace:Maui.Controls.Sample.Issues"
+    xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+    xmlns:local="clr-namespace:Maui.Controls.Sample.Issues"
+    x:Class="Maui.Controls.Sample.Issues.Issue26015">
+    <RefreshView>
+        <ScrollView>
+            <Grid RowDefinitions="*,*">
+                <ListView Grid.Row="0"
+                          ItemsSource="{Binding Data}"
+                          IsGroupingEnabled="True"
+                          HasUnevenRows="True">
+                    <ListView.GroupHeaderTemplate>
+                        <DataTemplate>
+                            <ViewCell>
+                                <Label Text="{Binding Name}"/>
+                            </ViewCell>
+                        </DataTemplate>
+                    </ListView.GroupHeaderTemplate>
+                    <ListView.ItemTemplate>
+                        <DataTemplate>
+                            <ViewCell>
+                                <Grid>
+                                    <Label Text="{Binding Detail}"/>
+                                    <Button Text="Remove"
+                                            AutomationId="{Binding Detail}"
+                                            Command="{Binding Source={RelativeSource AncestorType={x:Type local:Issue26015ViewModel}}, Path=RemoveItemCommand}"
+                                            CommandParameter="{Binding .}"/>
+                                </Grid>
+                            </ViewCell>
+                        </DataTemplate>
+                    </ListView.ItemTemplate>
+                </ListView>
+                <ListView
+                    Grid.Row="1"
+                    ItemsSource="{Binding Data}"
+                    IsGroupingEnabled="True"
+                    HasUnevenRows="True">
+                    <ListView.ItemTemplate>
+                        <DataTemplate>
+                            <ViewCell>
+                                <Grid>
+                                    <Label Text="{Binding Detail}"/>
+                                    <Button
+                                        Text="Remove"
+                                        Command="{Binding Source={RelativeSource AncestorType={x:Type local:Issue26015ViewModel}}, Path=RemoveItemCommand}"
+                                        CommandParameter="{Binding .}"/>
+                                </Grid>
+                            </ViewCell>
+                        </DataTemplate>
+                    </ListView.ItemTemplate>
+                </ListView>
+            </Grid>
+        </ScrollView>
+    </RefreshView>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue26015.xaml.cs

@@ -0,0 +1,77 @@
+using System.Collections.ObjectModel;
+using System.ComponentModel;
+
+namespace Maui.Controls.Sample.Issues
+{
+
+	[Issue(IssueTracker.Github, 26015, "MAUI Grouped ListView Remove Item Causes Error when more than one Group item exists", PlatformAffected.Android)]
+	public partial class Issue26015 : ContentPage
+	{
+		public Issue26015()
+		{
+			InitializeComponent();
+			BindingContext = new Issue26015ViewModel();
+		}
+	}
+
+	class Issue26015ViewModel : ViewModelBase
+	{
+		public class GroupData : ObservableCollection<DetailData>
+		{
+			public string Name { get; private set; }
+			public GroupData(string name, ObservableCollection<DetailData> d) : base(d)
+			{ Name = name; }
+		}
+
+		public class DetailData
+		{
+			public int Nr { get; set; }
+			public string Detail { get; set; }
+		}
+
+		private ObservableCollection<GroupData> _data;
+		public ObservableCollection<GroupData> Data
+		{
+			get => _data;
+			set
+			{
+				_data = value;
+				OnPropertyChanged();
+			}
+		}
+
+		public Command RemoveItemCommand => new Command<DetailData>(RemoveItem);
+
+		public Issue26015ViewModel()
+		{
+			Data =
+			[
+				new GroupData("Group1",
+					[
+						new(){ Nr = 1, Detail = "Test1" },
+						new(){ Nr = 2, Detail = "Test2" }
+					]),
+					new GroupData("Group2",
+					[
+						new(){ Nr = 3, Detail = "Test3" },
+						new(){ Nr = 4, Detail = "Test4" }
+					]),
+				];
+		}
+
+		private void RemoveItem(DetailData data)
+		{
+			foreach (var item in Data)
+			{
+				foreach (var child in item)
+				{
+					if (child.Nr == data.Nr)
+					{
+						item.Remove(child);
+						break;
+					}
+				}
+			}
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue26015.cs

@@ -0,0 +1,26 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue26015 : _IssuesUITest
+{
+
+	public Issue26015(TestDevice testDevice) : base(testDevice)
+	{
+	}
+
+	public override string Issue => "MAUI Grouped ListView Remove Item Causes Error when more than one Group item exists";
+
+	[Test]
+	[Category(UITestCategories.ListView)]
+	public void AppShouldNotCrashWhenRemovingItemsFromGroupedList()
+	{
+		App.WaitForElement("Test1");
+		App.Click("Test1");
+		App.Click("Test2");
+		App.Click("Test3");
+		App.Click("Test4");
+	}
+}