Skip to content

[Windows, Android] Fix ScrollView Content Not Removed When Set to Null #33069

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
PureWeen merged 6 commits into from
Dec 22, 2025
Merged

[Windows, Android] Fix ScrollView Content Not Removed When Set to Null #33069

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
586f247
fix added
devanathan-vaithiyanathan Dec 3, 2025
ff92c07
fix added
devanathan-vaithiyanathan Dec 8, 2025
a6a14b5
test added
devanathan-vaithiyanathan Dec 8, 2025
b8e794a
Modified the test case
devanathan-vaithiyanathan Dec 9, 2025
e05af7b
Update ScrollViewHandler.Windows.cs
devanathan-vaithiyanathan Dec 9, 2025
6de1a1b
test case added
devanathan-vaithiyanathan Dec 10, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
80 changes: 80 additions & 0 deletions src/Controls/tests/TestCases.HostApp/Issues/Issue33067.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,80 @@
using System.Collections.ObjectModel;
Copy link

Copilot AI Dec 9, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The System.Collections.ObjectModel namespace is not used in this file and should be removed.

Suggested change
using System.Collections.ObjectModel;

Copilot uses AI. Check for mistakes.

namespace Maui.Controls.Sample.Issues;

[Issue(IssueTracker.Github, 33067, "[Windows, Android] ScrollView Content Not Removed When Set to Null", PlatformAffected.Android | PlatformAffected.UWP)]

public class Issue33067 : ContentPage
{
ScrollView _scrollView = null!;
Label _originalContent = null!;
Button _setNullButton = null!;
Button _addContentButton = null!;

public Issue33067()
{
CreateUI();
}

void CreateUI()
{
// Create the original content label
_originalContent = new Label
{
Text = "This is a sample label inside the ScrollView that can be set to null and added back.",
Padding = new Thickness(20),
AutomationId = "ContentLabel",
FontSize = 16
};

// Create the ScrollView
_scrollView = new ScrollView
{
BackgroundColor = Colors.LightGray,
HeightRequest = 300,
Content = null
};

// Create the "Set Content to Null" button
_setNullButton = new Button
{
Text = "Set Content to Null",
AutomationId = "SetNullButton"
};
_setNullButton.Clicked += OnSetContentNullClicked;

// Create the "Add Content" button
_addContentButton = new Button
{
Text = "Add Content",
AutomationId = "AddContentButton"
};
_addContentButton.Clicked += OnAddContentClicked;

// Create the main layout
var layout = new VerticalStackLayout
{
Spacing = 20,
Padding = new Thickness(30),
Children = { _setNullButton, _addContentButton, _scrollView }
};

// Set the content of the page
Content = layout;
}

void OnSetContentNullClicked(object sender, EventArgs e)
{
// Set ScrollView content to null
_scrollView.Content = null;
}

void OnAddContentClicked(object sender, EventArgs e)
{
// Restore the original content
if (_originalContent != null)
{
_scrollView.Content = _originalContent;
}
Comment on lines +75 to +78
Copy link

Copilot AI Dec 9, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The null check for _originalContent is unnecessary here because it's initialized as null! (null-forgiving operator) on line 10 and is always assigned a non-null value in CreateUI() before any button click can occur. This check can be simplified to just _scrollView.Content = _originalContent;

Suggested change
if (_originalContent != null)
{
_scrollView.Content = _originalContent;
}
_scrollView.Content = _originalContent;

Copilot uses AI. Check for mistakes.
}
}
30 changes: 30 additions & 0 deletions src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue33067.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,30 @@
using NUnit.Framework;
using UITest.Appium;
using UITest.Core;

namespace Microsoft.Maui.TestCases.Tests.Issues;
public class Issue33067 : _IssuesUITest
{
public Issue33067(TestDevice device) : base(device) { }

public override string Issue => "[Windows, Android] ScrollView Content Not Removed When Set to Null";

[Test, Order(1)]
[Category(UITestCategories.ScrollView)]
public void VerifyScrollViewContentShouldNull()
{
App.WaitForElement("SetNullButton");
App.WaitForNoElement("ContentLabel");
}

[Test, Order(2)]
[Category(UITestCategories.ScrollView)]
public void VerifyScrollViewContentWhenSetToNull()
{
App.WaitForElement("SetNullButton");
App.Tap("AddContentButton");
App.WaitForElement("ContentLabel");
App.Tap("SetNullButton");
App.WaitForNoElement("ContentLabel");
}
}
15 changes: 13 additions & 2 deletions src/Core/src/Handlers/ScrollView/ScrollViewHandler.Android.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -196,15 +196,26 @@ The methods below exist to support inserting/updating the extra padding/margin l

static void UpdateInsetView(IScrollView scrollView, IScrollViewHandler handler, ICrossPlatformLayout crossPlatformLayout)
{
if (scrollView.PresentedContent == null || handler.MauiContext == null)
if (handler.MauiContext is null)
{
return;
}

// Find existing inset panel once
var currentPaddingLayer = FindInsetPanel(handler);

// If PresentedContent is null, clean up any existing content and return
if (scrollView.PresentedContent is null)
{
currentPaddingLayer?.RemoveAllViews();
return;
}

var nativeContent = scrollView.PresentedContent.ToPlatform(handler.MauiContext);

if (FindInsetPanel(handler) is ContentViewGroup currentPaddingLayer)
if (currentPaddingLayer is not null)
{
// Only update if content has changed or is missing
if (currentPaddingLayer.ChildCount == 0 || currentPaddingLayer.GetChildAt(0) != nativeContent)
{
currentPaddingLayer.RemoveAllViews();
Expand Down
19 changes: 16 additions & 3 deletions src/Core/src/Handlers/ScrollView/ScrollViewHandler.Windows.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -125,21 +125,34 @@ The methods below exist to support inserting/updating the padding/margin panel.

static void UpdateContentPanel(IScrollView scrollView, IScrollViewHandler handler, ICrossPlatformLayout crossPlatformLayout)
{
if (scrollView.PresentedContent == null || handler.MauiContext == null)
if (handler.MauiContext is null)
{
return;
}

var scrollViewer = handler.PlatformView;
var currentPaddingLayer = GetContentPanel(scrollViewer);

// If PresentedContent is null, clean up any existing content and return
if (scrollView.PresentedContent is null)
{
if (currentPaddingLayer is not null)
{
currentPaddingLayer.CachedChildren.Clear();
}

Copy link

Copilot AI Dec 9, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Trailing whitespace should be removed from this empty line. This can be caught by running dotnet format before committing.

Suggested change

Copilot uses AI. Check for mistakes.
return;
}

var nativeContent = scrollView.PresentedContent.ToPlatform(handler.MauiContext);

if (GetContentPanel(scrollViewer) is ContentPanel currentPaddingLayer)
if (currentPaddingLayer is not null)
{
// Only update if content has changed or is missing
if (currentPaddingLayer.CachedChildren.Count == 0 || currentPaddingLayer.CachedChildren[0] != nativeContent)
{
currentPaddingLayer.CachedChildren.Clear();
currentPaddingLayer.CachedChildren.Add(nativeContent);

}
}
else
Expand Down
Loading