Fix CollectionView.Header is header is not scrollable in Android platform

src/Controls/src/Core/Handlers/Items/Android/ItemContentView.cs

@@ -3,6 +3,8 @@
 using Android.Content;
 using Android.Views;
 using Microsoft.Maui.Graphics;
+using AndroidX.Core.Widget;
+using AndroidX.RecyclerView.Widget;
 using AView = Android.Views.View;
 
 namespace Microsoft.Maui.Controls.Handlers.Items
@@ -37,6 +39,75 @@ internal Func<Size?> RetrieveStaticSize
 			set => _retrieveStaticSize = new WeakReference(value);
 		}
 
+		public override bool DispatchTouchEvent(MotionEvent e)
+		{
+			if (IsHeaderOrFooterContent())
+			{
+
+				if (e.Action == MotionEventActions.Up || e.Action == MotionEventActions.Cancel)
+				{
+					Parent?.RequestDisallowInterceptTouchEvent(false);
+				}
+			}
+
+			return base.DispatchTouchEvent(e);
+		}
+
+		public override bool OnInterceptTouchEvent(MotionEvent ev)
+		{
+			if (IsHeaderOrFooterContent())
+			{
+				if (ev.Action == MotionEventActions.Down)
+				{
+					Parent?.RequestDisallowInterceptTouchEvent(true);
+					return false;
+				}
+			}
+
+			return base.OnInterceptTouchEvent(ev);
+		}
+
+		/// <summary>
+		/// Determines if this ItemContentView is being used for header or footer content
+		/// by checking if the contained View is the same as the ItemsView's Header or Footer
+		/// </summary>
+		bool IsHeaderOrFooterContent()
+		{
+			if (View == null)
+			{
+				return false;
+			}
+
+			// Find the parent ItemsView by traversing up the view hierarchy
+			var itemsView = FindParentItemsView();
+			if (itemsView is StructuredItemsView structuredItemsView)
+			{
+				// Check if our View is the same object reference as the header or footer
+				return ReferenceEquals(View, structuredItemsView.Header) ||
+					   ReferenceEquals(View, structuredItemsView.Footer);
+			}
+
+			return false;
+		}
+
+		/// <summary>
+		/// Finds the parent StructuredItemsView by traversing the logical parent chain
+		/// </summary>
+		StructuredItemsView FindParentItemsView()
+		{
+			var current = View?.Parent;
+			while (current != null)
+			{
+				if (current is StructuredItemsView itemsView)
+				{
+					return itemsView;
+				}
+
+				current = current.Parent;
+			}
+			return null;
+		}
+
 		internal void RealizeContent(View view, ItemsView itemsView)
 		{
 			Content = CreateHandler(view, itemsView);

src/Controls/src/Core/PublicAPI/net-android/PublicAPI.Unshipped.txt

@@ -1 +1,3 @@
 #nullable enable
+~override Microsoft.Maui.Controls.Handlers.Items.ItemContentView.DispatchTouchEvent(Android.Views.MotionEvent e) -> bool
+~override Microsoft.Maui.Controls.Handlers.Items.ItemContentView.OnInterceptTouchEvent(Android.Views.MotionEvent ev) -> bool

src/Controls/tests/TestCases.HostApp/Issues/Issue22120.cs

@@ -0,0 +1,86 @@
+using System.Collections.ObjectModel;
+using Microsoft.Maui.Controls;
+
+namespace Maui.Controls.Sample.Issues
+{
+    [Issue(IssueTracker.Github, 22120, "CollectionView.Header is not scrollable in Android platform",
+        PlatformAffected.Android)]
+    public class Issue22120 : ContentPage
+    {
+        public Issue22120()
+        {
+            Title = "Issue 22120";
+
+            // Create header items for the ListView inside ScrollView
+            var headerItems = new List<string>();
+            for (int i = 1; i <= 15; i++)
+            {
+                headerItems.Add($"Header Item {i}");
+            }
+
+            // Create collection items
+            var collectionItems = new List<string>
+            {
+                "Pink", "Green", "Blue", "Yellow", "Orange", "Purple", "SkyBlue", "PaleGreen"
+            };
+
+            // Create the ListView for the header content with ItemTemplate
+            var headerListView = new ListView
+            {
+                AutomationId = "Issue22120HeaderListView",
+                HorizontalOptions = LayoutOptions.Center,
+                ItemsSource = headerItems,
+                HeightRequest = 400,
+                ItemTemplate = new DataTemplate(() =>
+                {
+                    var label = new Label
+                    {
+                        Padding = new Thickness(10),
+                        BackgroundColor = Colors.LightBlue
+                    };
+                    label.SetBinding(Label.TextProperty, ".");
+
+                    return new ViewCell
+                    {
+                        View = label
+                    };
+                })
+            };
+
+            // Create the ScrollView for the header containing the ListView
+            var headerScrollView = new ScrollView
+            {
+                AutomationId = "Issue22120HeaderScrollView",
+                HeightRequest = 200,
+                Content = headerListView
+            };
+
+            // Create the main CollectionView
+            var collectionView = new CollectionView
+            {
+                AutomationId = "Issue22120CollectionView",
+                Margin = new Thickness(20),
+                HorizontalOptions = LayoutOptions.Fill,
+                VerticalOptions = LayoutOptions.Fill,
+                ItemsLayout = new GridItemsLayout(3, ItemsLayoutOrientation.Vertical),
+                Header = headerScrollView,
+                ItemsSource = collectionItems,
+                ItemTemplate = new DataTemplate(() =>
+                {
+                    var button = new Button
+                    {
+                        Margin = new Thickness(5),
+                        Padding = new Thickness(0),
+                        HeightRequest = 60,
+                        HorizontalOptions = LayoutOptions.Fill,
+                        VerticalOptions = LayoutOptions.Center
+                    };
+                    button.SetBinding(Button.TextProperty, ".");
+                    return button;
+                })
+            };
+
+            Content = collectionView;
+        }
+    }
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue22120.cs

@@ -0,0 +1,27 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue22120 : _IssuesUITest
+{
+    public Issue22120(TestDevice device) : base(device) { }
+
+    public override string Issue => "CollectionView.Header is not scrollable in Android platform";
+
+    [Test]
+    [Category(UITestCategories.CollectionView)]
+    public void CollectionViewHeaderScrollViewIsScrollable()
+    {
+        App.WaitForElement("Issue22120HeaderScrollView");
+        App.WaitForElement("Header Item 1");
+        App.ScrollDown("Issue22120HeaderScrollView", ScrollStrategy.Gesture, swipePercentage: 0.9, swipeSpeed: 1000);
+        App.WaitForElement("Header Item 7", timeout: TimeSpan.FromSeconds(5));
+        App.ScrollDown("Issue22120HeaderScrollView", ScrollStrategy.Gesture, swipePercentage: 0.9, swipeSpeed: 1000);
+        App.WaitForElement("Header Item 12", timeout: TimeSpan.FromSeconds(5));
+        App.ScrollUp("Issue22120HeaderScrollView", ScrollStrategy.Gesture, swipePercentage: 0.9, swipeSpeed: 1000);
+        App.ScrollUp("Issue22120HeaderScrollView", ScrollStrategy.Gesture, swipePercentage: 0.9, swipeSpeed: 1000);
+        App.WaitForElement("Header Item 1", timeout: TimeSpan.FromSeconds(5));
+    }
+}