[BUG] DrawingView Error : PlatformView cannot be null here when used with BindableLayout (Android and iOS)

[mahesh139]

Is there an existing issue for this?

• I have searched the existing issues

Did you read the "Reporting a bug" section on Contributing file?

• I have read the "Reporting a bug" section on Contributing file: https://github.com/CommunityToolkit/Maui/blob/main/CONTRIBUTING.md#reporting-a-bug

Current Behavior

Application crashes with PlatformView cannot be null here when drawing view is used inside bindable layout. app crashes while changing the item source of the bindable layout. This happens on both Android and iOS.

Error Started after upgrading to Microsoft.Maui.Controls 8.0.60+ (latest release 8.0.92 also has same problem.)

Please find Git repo that produces same error:
https://github.com/mahesh139/MAUIBugs

This was working fine with Microsoft.Maui.Controls 8.0.40

Expected Behavior

Changing bindable layout item source that contains drawing view must not crash.

Steps To Reproduce

1. Open and run the solution.
2. Click on "Section 2" button, this will change bindable layout item source (no items in source)
3. Click on "Section 1" button, App crashes with PlatformView cannot be null here error while changing item source.

Hope this video helps with re-production steps:
https://github.com/user-attachments/assets/ec693e41-b910-4d36-9d4c-12a6f7489072

Link to public reproduction project repository

https://github.com/mahesh139/MAUIBugs

Environment

• .NET MAUI CommunityToolkit:9.1.0
• OS: Win 10
• .NET MAUI:8
• Microsoft.Maui.Controls 8.0.92
• Microsoft.Maui.Controls.Compatibility 8.0.92

Anything else?

Same repo works fine for:
CommunityToolkit.Maui 9.0.0
Microsoft.Maui.Controls 8.0.40
Microsoft.Maui.Controls.Compatibility 8.0.40

[mahesh139]

Exception Log:

System.InvalidOperationException
PlatformView cannot be null here

void DrawingViewHandler.OnVirtualViewLinesCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
In App

Assembly:
CommunityToolkit.Maui.Core
Version:
1.0.0.0
Called from: ObservableCollection.cs in void ObservableCollection.OnCollectionChanged(NotifyCollectionChangedEventArgs e)

Show 3 more frames

void MauiDrawingViewExtensions.SetLines(IDrawingView drawingView, MauiDrawingView mauiDrawingView, IDrawingLineAdapter adapter)
In App

void DrawingViewHandler.OnPlatformViewLinesCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
In App

Called from: ObservableCollection.cs in void ObservableCollection.OnCollectionChanged(NotifyCollectionChangedEventArgs e)

Show 3 more frames

void MauiDrawingViewExtensions.SetLines(MauiDrawingView mauiDrawingView, IDrawingView drawingView)
In App

void DrawingViewHandler.MapLines(DrawingViewHandler handler, IDrawingView view)
In App

Called from: /_/src/Core/src/PropertyMapper.cs in void PropertyMapper<TVirtualView, TViewHandler>.Add(string key, Action<TViewHandler, TVirtualView> action)+(IElementHandler h, IElement v) => { }

Show 32 more frames

/_/MvvmHelpers/ObservableRangeCollection.cs in void ObservableRangeCollection.RaiseChangeNotificationEvents(NotifyCollectionChangedAction action, List changedItems, int startingIndex) at line 160:17
In App

/_/MvvmHelpers/ObservableRangeCollection.cs in void ObservableRangeCollection.ReplaceRange(IEnumerable collection) at line 140:4
In App

ViewModels\TestViewModel.cs in void TestViewModel.SetSection1Answers() at line 42:13
In App

ViewModels\TestViewModel.cs in void TestViewModel.RegisterCommands()+() => { } [0] at line 55:17
In App

Called from: /_/src/Controls/src/Core/Command.cs in Command(Action execute)+(object o) => { }