[CollectionView] Crash occurs when switching CollectionView.IsVisible right after setting ItemsSource

src/Controls/src/Core/Internals/PropertyPropagationExtensions.cs

@@ -1,12 +1,14 @@
 #nullable disable
 using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
 
 namespace Microsoft.Maui.Controls.Internals
 {
 	/// <include file="../../../docs/Microsoft.Maui.Controls.Internals/PropertyPropagationExtensions.xml" path="Type[@FullName='Microsoft.Maui.Controls.Internals.PropertyPropagationExtensions']/Docs/*" />
 	public static class PropertyPropagationExtensions
 	{
-		internal static void PropagatePropertyChanged(string propertyName, Element element, IEnumerable children)
+		internal static void PropagatePropertyChanged(string propertyName, Element element, IReadOnlyList<IVisualTreeElement> children)
 		{
 			if (propertyName == null || propertyName == VisualElement.FlowDirectionProperty.PropertyName)
 				SetFlowDirectionFromParent(element);
@@ -26,10 +28,12 @@ internal static void PropagatePropertyChanged(string propertyName, Element eleme
 			if (propertyName == null || propertyName == Shell.NavBarIsVisibleProperty.PropertyName)
 				BaseShellItem.PropagateFromParent(Shell.NavBarIsVisibleProperty, element);
 
-			foreach (var child in children)
+			foreach (var child in children.ToArray())
 			{
 				if (child is IPropertyPropagationController view)
+				{
 					view.PropagatePropertyChanged(propertyName);
+				}
 			}
 		}
 

src/Controls/tests/TestCases.HostApp/Issues/Issue28162.xaml

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue28162">
+    <VerticalStackLayout>
+        <Button Text="Toggle visibility"
+                AutomationId="button"
+                Clicked="Button_Clicked"/>
+        <CollectionView IsVisible="True"
+                        HorizontalOptions="Center"
+                        VerticalOptions="Center"
+                        x:Name="CollectionView">
+            <CollectionView.Header>
+                <ContentView HeightRequest="50"
+                             BackgroundColor="Green"/>
+            </CollectionView.Header>
+            <CollectionView.ItemTemplate>
+                <DataTemplate>
+                    <Border StrokeShape="RoundRectangle 10"
+                            Padding="20"
+                            Stroke="Red">
+                        <Label HorizontalOptions="Center"
+                               VerticalOptions="Center"
+                               Text="{Binding .}"/>
+                    </Border>
+                </DataTemplate>
+            </CollectionView.ItemTemplate>
+            <CollectionView.Footer>
+                <ContentView HeightRequest="50"
+                             BackgroundColor="Green"/>
+            </CollectionView.Footer>
+        </CollectionView>
+    </VerticalStackLayout>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue28162.xaml.cs

@@ -0,0 +1,19 @@
+using System.Collections.ObjectModel;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[Issue(IssueTracker.Github, 28162, "Crash occurs when switching CollectionView.IsVisible right after setting ItemsSource", PlatformAffected.iOS)]
+	public partial class Issue28162 : ContentPage
+	{
+		public Issue28162()
+		{
+			InitializeComponent();
+		}
+
+		private void Button_Clicked(object sender, EventArgs e)
+		{
+			CollectionView.ItemsSource = new ObservableCollection<string> { "Item 1", "Item 2", "Item 3" };
+			CollectionView.IsVisible = !CollectionView.IsVisible;
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue28162.cs

@@ -0,0 +1,23 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue28162 : _IssuesUITest
+	{
+		public Issue28162(TestDevice testDevice) : base(testDevice)
+		{
+		}
+
+		public override string Issue => "Crash occurs when switching CollectionView.IsVisible right after setting ItemsSource";
+
+		[Test]
+		[Category(UITestCategories.CollectionView)]
+		public void SwitchingVisibilityAndChangingItemsSourceShouldNotCrash()
+		{
+			App.WaitForElement("button");
+			App.Click("button");
+		}
+	}
+}