[iOS] Fix deselect item on CollectionView

src/Controls/src/Core/Handlers/Items/iOS/SelectableItemsViewController.cs

@@ -53,9 +53,15 @@ internal void ClearSelection()
 		{
 			var selectedItemIndexes = CollectionView.GetIndexPathsForSelectedItems();
 
-			foreach (var index in selectedItemIndexes)
+			if(selectedItemIndexes is not null && selectedItemIndexes.Any())
 			{
-				CollectionView.DeselectItem(index, true);
+				CollectionView.PerformBatchUpdates(null, _ =>
+				{
+					foreach (var index in selectedItemIndexes)
+					{
+						CollectionView.DeselectItem(index, true);
+					}
+				});
 			}
 		}
 
@@ -157,8 +163,11 @@ void SynchronizePlatformSelectionWithSelectedItems()
 			{
 				var itemAtPath = GetItemAtIndex(path);
 				if (!selectedItems.Contains(itemAtPath))
+				{
+					CollectionView.PerformBatchUpdates(null, _ =>
 				{
 					CollectionView.DeselectItem(path, true);
+					});
 				}
 				else
 				{

src/Controls/src/Core/Handlers/Items2/iOS/SelectableItemsViewController2.cs

@@ -40,7 +40,7 @@ internal void SelectItem(object selectedItem)
 
 			if (index.Section > -1 && index.Item > -1)
 			{
-                // Ensure the selected index is updated after the collection view's items generation is completed
+				// Ensure the selected index is updated after the collection view's items generation is completed
 				CollectionView.PerformBatchUpdates(null, _ =>
 				{
 					CollectionView.SelectItem(index, true, UICollectionViewScrollPosition.None);
@@ -53,10 +53,13 @@ internal void ClearSelection()
 		{
 			var selectedItemIndexes = CollectionView.GetIndexPathsForSelectedItems();
 
-			foreach (var index in selectedItemIndexes)
+			CollectionView.PerformBatchUpdates(null, _ =>
 			{
-				CollectionView.DeselectItem(index, true);
-			}
+				foreach (var index in selectedItemIndexes)
+				{
+					CollectionView.DeselectItem(index, true);
+				}
+			});
 		}
 
 		void FormsSelectItem(NSIndexPath indexPath)
@@ -158,7 +161,10 @@ void SynchronizePlatformSelectionWithSelectedItems()
 				var itemAtPath = GetItemAtIndex(path);
 				if (!selectedItems.Contains(itemAtPath))
 				{
-					CollectionView.DeselectItem(path, true);
+					CollectionView.PerformBatchUpdates(null, _ =>
+					{
+						CollectionView.DeselectItem(path, true);
+					});
 				}
 				else
 				{

src/Controls/tests/TestCases.HostApp/Issues/Issue26187.cs

@@ -0,0 +1,92 @@
+using System.Collections.ObjectModel;
+
+namespace Maui.Controls.Sample.Issues
+{
+    [Issue(IssueTracker.Github, 26187, "[MAUI] Select items traces are preserved", PlatformAffected.iOS)]
+    public class Issue26187 : NavigationPage
+    {
+        public Issue26187()
+        {
+            PushAsync(new CollectionViewSelectedItemNullPage());
+        }
+    }
+
+    public class CollectionViewSelectedItemNullPage : ContentPage
+    {
+        public ObservableCollection<string> Items { get; set; }
+
+        public string SelectedItem { get; set; }
+
+        public CollectionViewSelectedItemNullPage()
+        {
+            Items = new ObservableCollection<string>
+                {
+                    "Item 1",
+                    "Item 2",
+                    "Item 3",
+                    "Item 4",
+                    "Item 5"
+                };
+            SelectedItem = Items.LastOrDefault();
+            var cv = new CollectionView
+            {
+                SelectionMode = SelectionMode.Single,
+                ItemTemplate = new DataTemplate(() =>
+                {
+                    var label = new Label
+                    {
+                        FontSize = 24,
+                        HorizontalOptions = LayoutOptions.FillAndExpand,
+                        VerticalOptions = LayoutOptions.Center,
+                        AutomationId ="lblItem"
+                    };
+                    label.SetBinding(Label.TextProperty, ".");
+
+                    return new HorizontalStackLayout
+                    {
+                        Children = { label }
+                    };
+                })
+
+            };
+
+            cv.SetBinding(CollectionView.ItemsSourceProperty, new Binding(nameof(Items)));
+          //  cv.SetBinding(CollectionView.SelectedItemProperty, new Binding(nameof(SelectedItem)));
+            Content = cv;
+
+            BindingContext = this;
+          //  cv.SelectedItem = SelectedItem;
+
+           cv.SelectionChanged += CollectionView_SelectionChanged;
+        }
+
+        async void CollectionView_SelectionChanged(object sender, SelectionChangedEventArgs e)
+        {
+            if (e.CurrentSelection.FirstOrDefault() is string issue)
+            {
+                await Navigation.PushAsync(new NewPage(issue));
+            }
+
+            // Clear Selection
+            var cv = sender as CollectionView;
+            if (cv is not null)
+            {
+                cv.SelectedItem = null;
+            }
+        }
+
+        class NewPage : ContentPage
+        {
+            public NewPage(string item)
+            {
+                Title = item;
+                Content = new Button
+                {
+                    Text = $"Go Back Selected Item null from {item}",
+                    Command = new Command(() => Navigation.PopAsync()),
+                    AutomationId = "btnGoBack"
+                };
+            }
+        }
+    }
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue26187.cs

@@ -0,0 +1,27 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue26187 : _IssuesUITest
+	{
+		public override string Issue => "[MAUI] Select items traces are preserved";
+
+		public Issue26187(TestDevice device)
+		: base(device)
+		{ }
+
+		[Test]
+		[Category(UITestCategories.CollectionView)]
+		public void SelectedItemVisualIsCleared()
+		{
+			App.WaitForElement("lblItem");
+			App.Tap("lblItem");
+			App.WaitForElement("btnGoBack");
+			App.Tap("btnGoBack");
+			App.WaitForElement("lblItem");
+			VerifyScreenshot();
+		}
+	}
+}