CollectionView with EmptyView and EmptyViewTemplate for Data template selector throws an exception

src/Controls/samples/Controls.Sample/Pages/Controls/CollectionViewGalleries/EmptyViewGalleries/EmptyViewGallery.cs

@@ -31,6 +31,8 @@ public EmptyViewGallery()
 							new EmptyViewTemplateGallery(), Navigation),
 						GalleryBuilder.NavButton("EmptyView (Swap EmptyView)", () =>
 							new EmptyViewSwapGallery(), Navigation),
+						GalleryBuilder.NavButton("EmptyView (Data Template Selector)", () =>
+						new EmptyViewWithDataTemplateSelector(), Navigation),
 						GalleryBuilder.NavButton("EmptyView (load simulation)", () =>
 							new EmptyViewLoadSimulateGallery(), Navigation),
 						GalleryBuilder.NavButton("EmptyView RTL", () =>

src/Controls/samples/Controls.Sample/Pages/Controls/CollectionViewGalleries/EmptyViewGalleries/EmptyViewWithDataTemplateSelector.xaml

@@ -0,0 +1,72 @@
+<?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.Pages.CollectionViewGalleries.EmptyViewGalleries.EmptyViewWithDataTemplateSelector">
+    <ContentPage.Resources>
+    <DataTemplate x:Key="AdvancedTemplate">
+      <StackLayout>
+        <Label Text="No results matched your filter."
+                 Margin="10,25,10,10"
+                 FontAttributes="Bold"
+                 FontSize="18"
+                 HorizontalOptions="Fill"
+                 HorizontalTextAlignment="Center"/>
+        <Label Text="Try a broader filter?"
+                 FontAttributes="Italic"
+                 FontSize="12"
+                 HorizontalOptions="Fill"
+                 HorizontalTextAlignment="Center"/>
+      </StackLayout>
+    </DataTemplate>
+
+    <DataTemplate x:Key="BasicTemplate">
+      <Label Text="No items to display."
+             Margin="10,25,10,10"
+             FontAttributes="Bold"
+             FontSize="18"
+             HorizontalOptions="Fill"
+             HorizontalTextAlignment="Center"/>
+    </DataTemplate>
+  </ContentPage.Resources>
+  <Grid Margin="20" RowDefinitions="Auto, Auto, *">
+    <StackLayout Grid.Row="0">
+      <Label Text="1. The test passes if you are able to filter below items by search term." />
+      <Label Text="2. The test passes if the filtering 'Xamarin'(no matched results), the string 'No items to display.' will be displayed." />
+      <Label Text="3. The test passes if the filtering operation yields no data(except Xamarin), the strings 'No results matched your filter.' and 'Try a broader filter?' will be displayed." />
+    </StackLayout>
+    <SearchBar Grid.Row="1"
+             x:Name="searchBar"
+             AutomationId="SearchBar"
+             SearchCommand="{Binding FilterCommand}"
+             SearchCommandParameter="{Binding Source={x:Reference searchBar}, Path=Text}"
+             Placeholder="Filter" />
+    <CollectionView Grid.Row="2"
+                  x:Name="collectionView"
+                  AutomationId="Success"
+                  ItemsSource="{Binding Monkeys}"
+                  EmptyView="{Binding Source={x:Reference searchBar}, Path=Text}">
+      <CollectionView.ItemTemplate>
+        <DataTemplate>
+          <Grid Padding="10">
+            <Grid.RowDefinitions>
+              <RowDefinition Height="Auto" />
+              <RowDefinition Height="Auto" />
+            </Grid.RowDefinitions>
+            <Grid.ColumnDefinitions>
+              <ColumnDefinition Width="Auto" />
+              <ColumnDefinition Width="Auto" />
+            </Grid.ColumnDefinitions>
+            <Label Grid.Column="1"
+                         Text="{Binding Name}"
+                         FontAttributes="Bold" />
+            <Label Grid.Row="1"
+                         Grid.Column="1"
+                         Text="{Binding Location}"
+                         FontAttributes="Italic"
+                         VerticalOptions="End" />
+          </Grid>
+        </DataTemplate>
+      </CollectionView.ItemTemplate>
+    </CollectionView>
+  </Grid>
+</ContentPage>

src/Controls/samples/Controls.Sample/Pages/Controls/CollectionViewGalleries/EmptyViewGalleries/EmptyViewWithDataTemplateSelector.xaml.cs

@@ -0,0 +1,75 @@
+#nullable enable
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.ComponentModel;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Windows.Input;
+
+namespace Maui.Controls.Sample.Pages.CollectionViewGalleries.EmptyViewGalleries
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	public partial class EmptyViewWithDataTemplateSelector : ContentPage
+	{
+		public EmptyViewWithDataTemplateSelector()
+		{
+			InitializeComponent();
+            var emptyViewTemplateSelector = new SearchTermDataTemplateSelector
+            {
+                DefaultTemplate = (DataTemplate)Resources["AdvancedTemplate"],
+                OtherTemplate = (DataTemplate)Resources["BasicTemplate"]
+            };
+            collectionView.EmptyViewTemplate = emptyViewTemplateSelector;
+            BindingContext = new EmptyViewWithDataTemplateSelectorViewModel();
+		}
+
+		public class Monkey
+        {
+            public string? Name { get; set; }
+            public string? Location { get; set; }
+            public string? Details { get; set; }
+        }
+
+		public class SearchTermDataTemplateSelector : DataTemplateSelector
+        {
+            public DataTemplate? DefaultTemplate { get; set; }
+            public DataTemplate? OtherTemplate { get; set; }
+
+            protected override DataTemplate? OnSelectTemplate(object item, BindableObject container)
+			{
+				string query = (string)item;
+				return query.Equals("xamarin", StringComparison.OrdinalIgnoreCase) ? OtherTemplate : DefaultTemplate;
+			}
+        }
+
+		internal class EmptyViewWithDataTemplateSelectorViewModel
+		{
+			public ObservableCollection<Monkey> Monkeys { get; } = new();
+            public ICommand FilterCommand => new Command<string>(FilterItems);
+
+            public EmptyViewWithDataTemplateSelectorViewModel()
+            {
+                // Directly populate the ObservableCollection
+                Monkeys.Add(new Monkey
+                {
+                    Name = "Baboon",
+                    Location = "Africa & Asia",
+                    Details = "Baboons are African and Arabian Old World monkeys belonging to the genus Papio, part of the subfamily Cercopithecinae."
+                });
+            }
+
+            private void FilterItems(string filter)
+            {
+                var filteredItems = Monkeys.Where(monkey => monkey.Name?.Contains(filter, StringComparison.OrdinalIgnoreCase) ?? false).ToList();
+                Monkeys.Clear();
+                foreach (var monkey in filteredItems)
+                {
+                    Monkeys.Add(monkey);
+                }
+            }
+		}
+	}
+}

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

@@ -567,7 +567,7 @@ protected virtual void HandleFormsElementMeasureInvalidated(VisualElement formsE
 		internal void UpdateView(object view, DataTemplate viewTemplate, ref UIView uiView, ref VisualElement formsElement)
 		{
 			// Is view set on the ItemsView?
-			if (view is null && viewTemplate is null)
+			if (view is null && (viewTemplate is null || viewTemplate is DataTemplateSelector))
 			{
 				if (formsElement != null)
 				{

src/Controls/src/Core/Handlers/Items2/iOS/ItemsViewController2.cs

@@ -401,7 +401,7 @@ protected virtual CGRect DetermineEmptyViewFrame()
 		internal void UpdateView(object view, DataTemplate viewTemplate, ref UIView uiView, ref VisualElement formsElement)
 		{
 			// Is view set on the ItemsView?
-			if (view == null && viewTemplate is null)
+			if (view is null && (viewTemplate is null || viewTemplate is DataTemplateSelector))
 			{
 				if (formsElement != null)
 				{

src/Controls/tests/TestCases.HostApp/Issues/Issue25224.xaml

@@ -0,0 +1,76 @@
+<?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.Issue25224"
+             xmlns:local="clr-namespace:Maui.Controls.Sample.Issues"
+             x:Name="ThisMainPage"
+             Title="Main Page">
+
+  <ContentPage.Resources>
+    <DataTemplate x:Key="AdvancedTemplate">
+      <StackLayout>
+        <Label Text="No results matched your filter."
+                 Margin="10,25,10,10"
+                 FontAttributes="Bold"
+                 FontSize="18"
+                 HorizontalOptions="Fill"
+                 HorizontalTextAlignment="Center"/>
+        <Label Text="Try a broader filter?"
+                 FontAttributes="Italic"
+                 FontSize="12"
+                 HorizontalOptions="Fill"
+                 HorizontalTextAlignment="Center"/>
+      </StackLayout>
+    </DataTemplate>
+
+    <DataTemplate x:Key="BasicTemplate">
+      <Label Text="No items to display."
+             Margin="10,25,10,10"
+             FontAttributes="Bold"
+             FontSize="18"
+             HorizontalOptions="Fill"
+             HorizontalTextAlignment="Center"/>
+    </DataTemplate>
+  </ContentPage.Resources>
+  <Grid Margin="20" RowDefinitions="Auto, Auto, *">
+    <StackLayout Grid.Row="0">
+      <Label Text="1. The test passes if you are able to filter below items by search term." />
+      <Label Text="2. The test passes if the filtering 'Xamarin'(no matched results), the string 'No items to display.' will be displayed." />
+      <Label Text="3. The test passes if the filtering operation yields no data(except Xamarin), the strings 'No results matched your filter.' and 'Try a broader filter?' will be displayed." />
+    </StackLayout>
+    <SearchBar Grid.Row="1"
+             x:Name="searchBar"
+             AutomationId="SearchBar"
+             SearchCommand="{Binding FilterCommand}"
+             SearchCommandParameter="{Binding Source={x:Reference searchBar}, Path=Text}"
+             Placeholder="Filter" />
+    <CollectionView Grid.Row="2"
+                  x:Name="collectionView"
+                  AutomationId="Success"
+                  ItemsSource="{Binding Monkeys}"
+                  EmptyView="{Binding Source={x:Reference searchBar}, Path=Text}">
+      <CollectionView.ItemTemplate>
+        <DataTemplate>
+          <Grid Padding="10">
+            <Grid.RowDefinitions>
+              <RowDefinition Height="Auto" />
+              <RowDefinition Height="Auto" />
+            </Grid.RowDefinitions>
+            <Grid.ColumnDefinitions>
+              <ColumnDefinition Width="Auto" />
+              <ColumnDefinition Width="Auto" />
+            </Grid.ColumnDefinitions>
+            <Label Grid.Column="1"
+                         Text="{Binding Name}"
+                         FontAttributes="Bold" />
+            <Label Grid.Row="1"
+                         Grid.Column="1"
+                         Text="{Binding Location}"
+                         FontAttributes="Italic"
+                         VerticalOptions="End" />
+          </Grid>
+        </DataTemplate>
+      </CollectionView.ItemTemplate>
+    </CollectionView>
+  </Grid>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue25224.xaml.cs

@@ -0,0 +1,64 @@
+#nullable enable
+using System.Collections.ObjectModel;
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+using System.Windows.Input;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	[Issue(IssueTracker.Github, 25224, "CollectionView - EmptyView with EmptyViewTemplate for Data template selector page throws an exception", PlatformAffected.iOS)]
+	public partial class Issue25224: ContentPage
+	{
+		public Issue25224()
+		{
+			InitializeComponent();
+            var emptyViewTemplateSelector = new SearchTermDataTemplateSelector
+            {
+                DefaultTemplate = (DataTemplate)Resources["AdvancedTemplate"],
+                OtherTemplate = (DataTemplate)Resources["BasicTemplate"]
+            };
+            collectionView.EmptyViewTemplate = emptyViewTemplateSelector;
+            BindingContext = new Issue25224ViewModel();
+		}
+
+		public class SearchTermDataTemplateSelector : DataTemplateSelector
+        {
+            public DataTemplate? DefaultTemplate { get; set; }
+            public DataTemplate? OtherTemplate { get; set; }
+
+            protected override DataTemplate? OnSelectTemplate(object item, BindableObject container)
+			{
+				string query = (string)item;
+				return query.Equals("xamarin", StringComparison.OrdinalIgnoreCase) ? OtherTemplate : DefaultTemplate;
+			}
+        }
+
+		internal class Issue25224ViewModel
+		{
+			public ObservableCollection<Monkey> Monkeys { get; } = new();
+            public ICommand FilterCommand => new Command<string>(FilterItems);
+
+            public Issue25224ViewModel()
+            {
+                // Directly populate the ObservableCollection
+                Monkeys.Add(new Monkey
+                {
+                    Name = "Baboon",
+                    Location = "Africa & Asia",
+                    Details = "Baboons are African and Arabian Old World monkeys belonging to the genus Papio, part of the subfamily Cercopithecinae."
+                });
+            }
+
+            private void FilterItems(string filter)
+            {
+                var filteredItems = Monkeys.Where(monkey => monkey.Name?.Contains(filter, StringComparison.OrdinalIgnoreCase) ?? false).ToList();
+                Monkeys.Clear();
+                foreach (var monkey in filteredItems)
+                {
+                    Monkeys.Add(monkey);
+                }
+            }
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue25224.cs

@@ -0,0 +1,36 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	internal class Issue25224 : _IssuesUITest
+	{
+		public Issue25224(TestDevice device) : base(device) { }
+
+		public override string Issue => "CollectionView - EmptyView with EmptyViewTemplate for Data template selector page throws an exception";
+
+		[Test]
+		[Category(UITestCategories.CollectionView)]
+		public void CollectionViewEmptyViewDefaultTemplateShouldNotCrashOnDisplay()
+		{
+			App.WaitForElement("SearchBar");
+			App.EnterText("SearchBar", "test");
+			App.PressEnter();
+			// On UI test, pressing Enter twice performs filtering and shows the empty view.
+			// This code is necessary due to the app's behavior on UI test, which differs from simple samples.
+			App.PressEnter();
+			App.WaitForElement("Success");
+		}
+
+		[Test]
+		[Category(UITestCategories.CollectionView)]
+		public void CollectionViewEmptyViewOtherTemplateShouldNotCrashOnDisplay()
+		{
+			App.WaitForElement("SearchBar");
+			App.EnterText("SearchBar", "xamarin");
+			App.PressEnter();
+			App.WaitForElement("Success");
+		}
+	}
+}