Fix ListView.ScrollTo to Align SelectedItem with Center or End on Windows

src/Controls/src/Core/Compatibility/Handlers/ListView/Windows/ListViewRenderer.cs

@@ -578,15 +578,31 @@ async void OnViewChangeCompleted(object sender, SemanticZoomViewChangedEventArgs
 			ScrollTo(listProxy.ProxiedEnumerable, listProxy[0], ScrollToPosition.Start, true, true);
 		}
 
-		bool ScrollToItemWithAnimation(ScrollViewer viewer, object item)
+		bool ScrollToItemWithAnimation(ScrollViewer viewer, object item, ScrollToPosition toPosition)
 		{
 			var selectorItem = List.ContainerFromItem(item) as Microsoft.UI.Xaml.Controls.Primitives.SelectorItem;
 			var transform = selectorItem?.TransformToVisual(viewer.Content as UIElement);
 			var position = transform?.TransformPoint(new global::Windows.Foundation.Point(0, 0));
 			if (!position.HasValue)
 				return false;
 			// scroll with animation
-			viewer.ChangeView(position.Value.X, position.Value.Y, null);
+			switch (toPosition)
+			{
+				case ScrollToPosition.Center:
+				case ScrollToPosition.End:
+					{
+						double offset = viewer.ViewportHeight - selectorItem.DesiredSize.Height;
+						if (toPosition == ScrollToPosition.Center)
+							viewer.ChangeView(position.Value.X, position.Value.Y - (offset / 2), null);
+						else
+							viewer.ChangeView(position.Value.X, position.Value.Y - offset, null);
+						break;
+					}
+				default:
+					viewer.ChangeView(position.Value.X, position.Value.Y, null);
+					break;
+			}
+
 			return true;
 		}
 
@@ -617,7 +633,7 @@ async void ScrollTo(object group, object item, ScrollToPosition toPosition, bool
 			object c = t[location.Item2];
 
 			// scroll to desired item with animation
-			if (shouldAnimate && ScrollToItemWithAnimation(viewer, c))
+			if (shouldAnimate && ScrollToItemWithAnimation(viewer, c, toPosition))
 				return;
 
 			double viewportHeight = viewer.ViewportHeight;

src/Controls/tests/TestCases.HostApp/Issues/Issue26857.cs

@@ -0,0 +1,135 @@
+using System.Collections.ObjectModel;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[Issue(IssueTracker.Github, 26857, "ListView ScrollTo position always remains at the start even when set to Center or End", PlatformAffected.All)]
+	public class Issue26857 : ContentPage
+	{
+		private ListView ListView;
+		private ObservableCollection<string> Items;
+
+		public Issue26857()
+		{
+			Items = new ObservableCollection<string>
+			{
+				"Item 1",
+				"Item 2",
+				"Item 3",
+				"Item 4",
+				"Item 5",
+				"Item 6",
+				"Item 7",
+				"Item 8",
+				"Item 9",
+				"Item 10",
+				"Item 11",
+				"Item 12",
+				"Item 13",
+				"Item 14",
+				"Item 15",
+				"Item 16",
+				"Item 17",
+				"Item 18",
+				"Item 19",
+				"Item 20",
+				"Item 21",
+				"Item 22",
+				"Item 23",
+				"Item 24",
+				"Item 25",
+			};
+
+			ListView = new ListView
+			{
+				ItemsSource = Items,
+				SelectedItem = "Item 10",
+				VerticalOptions = LayoutOptions.Center,
+				HorizontalOptions = LayoutOptions.Center,
+				WidthRequest = 300,
+				HeightRequest = 220,
+			};
+
+			var horizontalStack = new StackLayout
+			{
+				Orientation = StackOrientation.Horizontal,
+				HorizontalOptions = LayoutOptions.Center,
+				Spacing = 20
+			};
+
+			var startButton = new Button
+			{
+				Text = "Start",
+				AutomationId = "StartButton",
+			};
+			startButton.Clicked += ScrollPositionStart_Clicked;
+
+			var centerButton = new Button
+			{
+				Text = "Center",
+				AutomationId = "CenterButton",
+			};
+			centerButton.Clicked += ScrollPositionCenter_Clicked;
+
+			var endButton = new Button
+			{
+				Text = "End",
+				AutomationId = "EndButton",
+			};
+			endButton.Clicked += ScrollPositionEnd_Clicked;
+
+			horizontalStack.Children.Add(startButton);
+			horizontalStack.Children.Add(centerButton);
+			horizontalStack.Children.Add(endButton);
+
+			var stackLayout = new StackLayout
+			{
+				Orientation = StackOrientation.Vertical,
+				Spacing = 20
+			};
+
+			stackLayout.Children.Add(ListView);
+			stackLayout.Children.Add(horizontalStack);
+			this.Content = stackLayout;
+		}
+
+		private void ScrollToSelectedItem(ScrollToPosition toPosition)
+		{
+			if (ListView?.SelectedItem != null)
+			{
+				switch (toPosition)
+				{
+					case ScrollToPosition.Start:
+						ListView.ScrollTo(ListView.SelectedItem, ScrollToPosition.Start, true);
+						break;
+					case ScrollToPosition.Center:
+						ListView.ScrollTo(ListView.SelectedItem, ScrollToPosition.Center, true);
+						break;
+					case ScrollToPosition.End:
+						ListView.ScrollTo(ListView.SelectedItem, ScrollToPosition.End, true);
+						break;
+				}	
+			}
+		}
+
+		private void ScrollPositionStart_Clicked(object sender, EventArgs e)
+		{
+			var currentIndex = Items.IndexOf(ListView.SelectedItem as string);
+			ListView.SelectedItem = Items[currentIndex + 2];
+			ScrollToSelectedItem(ScrollToPosition.Start);
+		}
+
+		private void ScrollPositionCenter_Clicked(object sender, EventArgs e)
+		{
+			var currentIndex = Items.IndexOf(ListView.SelectedItem as string);
+			ListView.SelectedItem = Items[currentIndex + 2];
+			ScrollToSelectedItem(ScrollToPosition.Center);
+		}
+
+		private void ScrollPositionEnd_Clicked(object sender, EventArgs e)
+		{
+			var currentIndex = Items.IndexOf(ListView.SelectedItem as string);
+			ListView.SelectedItem = Items[currentIndex + 2];
+			ScrollToSelectedItem(ScrollToPosition.End);
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue26857.cs

@@ -0,0 +1,44 @@
+
+using NUnit.Framework;
+using NUnit.Framework.Legacy;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue26857 : _IssuesUITest
+	{
+		public override string Issue => "ListView ScrollTo position always remains at the start even when set to Center or End";
+
+		public Issue26857(TestDevice device) : base(device)
+		{
+		}
+
+		[Test]
+		[Category(UITestCategories.ListView)]
+		public void Issue26857_SelectItemPositionStart()
+		{
+			App.WaitForElement("StartButton");
+			App.Tap("StartButton");
+			VerifyScreenshot();
+		}
+
+		[Test]
+		[Category(UITestCategories.ListView)]
+		public void Issue26857Test_SelectItemPositionCenter()
+		{
+			App.WaitForElement("CenterButton");
+			App.Tap("CenterButton");
+			VerifyScreenshot();
+		}
+
+		[Test]
+		[Category(UITestCategories.ListView)]
+		public void Issue26857Test_SelectItemPositionEnd()
+		{
+			App.WaitForElement("EndButton");
+			App.Tap("EndButton");
+			VerifyScreenshot();
+		}
+	}
+}