Using CollectionView.EmptyView results in an Exception on Windows

[omghb]

Description

We get an Exception from CollectionView.EmptyView after migrating from MAUI 8.0.93 to MAUI 9.0.40.

If we add items to the CollectionView and then navigate a second time to this page we get the exception Element is already the child of another element on Windows. This results in a crash of the App.

Development note: The Page using the CollectionView is a singleton.

Steps to Reproduce

1. Clone and run repro solution from GitHub repo: https://github.com/omghb/MauiIssue28212
2. Perform the same steps than shown in the video:
   
3. If you change the MAUI version to 8.0.93 then this issue will no occur.

Link to public reproduction project repository

No response

Version with bug

9.0.40 SR4

Is this a regression from previous behavior?

Yes, this used to work in .NET MAUI

Last version that worked well

8.0.93 SR9.3

Affected platforms

• Windows
• Not affected platforms: The same navigation works fine on Android and iOS.

Affected platform versions

Win 10 22H2

Did you find any workaround?

protected override void OnAppearing()
{
    base.OnAppearing();
    collectionView.EmptyView = new CustomEmptyView();
}

protected override void OnDisappearing()
{
    collectionView.EmptyView = null;
    base.OnDisappearing();
}

Relevant log output

Microsoft.UI.Xaml.UnhandledExceptionEventArgs

No installed components were detected.

Element is already the child of another element.


at WinRT.ExceptionHelpers.<ThrowExceptionForHR>g__Throw|38_0(Int32 hr)
   at ABI.Microsoft.UI.Xaml.Controls.IContentControlMethods.set_Content(IObjectReference _obj, Object value)
   at Microsoft.UI.Xaml.Controls.ContentControl.set_Content(Object value)
   at Microsoft.Maui.Controls.Platform.FormsListView.OnApplyTemplate()
   at Microsoft.UI.Xaml.FrameworkElement.Microsoft.UI.Xaml.IFrameworkElementOverrides.OnApplyTemplate()
   at ABI.Microsoft.UI.Xaml.IFrameworkElementOverrides.Do_Abi_OnApplyTemplate_2(IntPtr thisPtr)
--- End of stack trace from previous location ---
   at WinRT.ExceptionHelpers.<ThrowExceptionForHR>g__Throw|38_0(Int32 hr)
   at ABI.Microsoft.UI.Xaml.IUIElementMethods.Measure(IObjectReference _obj, Size availableSize)
   at Microsoft.UI.Xaml.UIElement.Measure(Size availableSize)
   at Microsoft.Maui.ViewHandlerExtensions.GetDesiredSizeFromHandler(IViewHandler viewHandler, Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Handlers.ViewHandler`2.GetDesiredSize(Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Layouts.LayoutExtensions.ComputeDesiredSize(IView view, Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Controls.VisualElement.MeasureOverride(Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Controls.VisualElement.Microsoft.Maui.IView.Measure(Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Layouts.GridLayoutManager.GridStructure.MeasureCell(Cell cell, Double width, Double height)
   at Microsoft.Maui.Layouts.GridLayoutManager.GridStructure.SecondMeasurePass()
   at Microsoft.Maui.Layouts.GridLayoutManager.GridStructure.MeasureCells()
   at Microsoft.Maui.Layouts.GridLayoutManager.GridStructure..ctor(IGridLayout grid, Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Layouts.GridLayoutManager.Measure(Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Controls.Layout.CrossPlatformMeasure(Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Platform.MauiPanel.CrossPlatformMeasure(Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Platform.MauiPanel.MeasureOverride(Size availableSize)
   at Microsoft.UI.Xaml.FrameworkElement.Microsoft.UI.Xaml.IFrameworkElementOverrides.MeasureOverride(Size availableSize)
   at ABI.Microsoft.UI.Xaml.IFrameworkElementOverrides.Do_Abi_MeasureOverride_0(IntPtr thisPtr, Size availableSize, Size* result)
--- End of stack trace from previous location ---
   at WinRT.ExceptionHelpers.<ThrowExceptionForHR>g__Throw|38_0(Int32 hr)
   at ABI.Microsoft.UI.Xaml.IUIElementMethods.Measure(IObjectReference _obj, Size availableSize)
   at Microsoft.UI.Xaml.UIElement.Measure(Size availableSize)
   at Microsoft.Maui.ViewHandlerExtensions.GetDesiredSizeFromHandler(IViewHandler viewHandler, Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Handlers.ViewHandler`2.GetDesiredSize(Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Layouts.LayoutExtensions.ComputeDesiredSize(IView view, Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Controls.VisualElement.MeasureOverride(Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Controls.VisualElement.Microsoft.Maui.IView.Measure(Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Layouts.LayoutExtensions.MeasureContent(IContentView contentView, Thickness inset, Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Layouts.LayoutExtensions.MeasureContent(IContentView contentView, Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Controls.ContentPage.Microsoft.Maui.ICrossPlatformLayout.CrossPlatformMeasure(Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Platform.MauiPanel.CrossPlatformMeasure(Double widthConstraint, Double heightConstraint)
   at Microsoft.Maui.Platform.MauiPanel.MeasureOverride(Size availableSize)
   at Microsoft.UI.Xaml.FrameworkElement.Microsoft.UI.Xaml.IFrameworkElementOverrides.MeasureOverride(Size availableSize)
   at ABI.Microsoft.UI.Xaml.IFrameworkElementOverrides.Do_Abi_MeasureOverride_0(IntPtr thisPtr, Size availableSize, Size* result)

[similar-issues-ai]

We've found some similar issues:

• [Android] CollectionView: VirtualView cannot be null here, when clearing and adding items on second navigation #12219 , similarity score: 81%

If any of the above are duplicates, please consider closing this issue out and adding additional context in the original issue.

Note: You can give me feedback by 👍 or 👎 this comment.

[Zhanglirong-Winnie]

This issue has been verified Visual Studio 17.14 Preview 1.1(9.0.40 & 9.0.0). Can repro this issue on Windows platform. On 8.0.100 works fine.

[sheiksyedm]

The fix has been merged into the main branch via PR #28560. Therefore, this issue can now be closed.