Glitchy ListBox when adding items & setting SelectedIndex

[metal450]

Describe the bug

In my app, I've got a page where I show Log messages in a ListBox:

<ListBox ItemsSource="{Binding LogItems}" SelectedIndex="{Binding SelectedIndex}">
  <ListBox.ItemTemplate>
      <DataTemplate>
         <Border BorderThickness="0,0,0,1" Padding="5 0" >
             <TextBlock Text="{Binding}" Margin="0" Padding="0" TextWrapping="Wrap"/>
         </Border>
     </DataTemplate>
  </ListBox.ItemTemplate>
</ListBox>

And:

    public ObservableCollection<string> LogItems
    {
        get => _logItems;
        set => this.RaiseAndSetIfChanged(ref _logItems, value);
    }
    private ObservableCollection<string> _logItems = new ObservableCollection<string>();

    public int SelectedIndex
    {
        get => _selectedIndex;
        set => this.RaiseAndSetIfChanged(ref _selectedIndex, value);
    }
    private int _selectedIndex = -1;

    public void AddLog(string log)
    {
        LogItems.Add(log);
        //SelectedIndex = LogItems.Count - 1;
    }

The above code works fine.

However, if I uncomment the SelectedItem line so that the ListBox will scroll to the bottom each time a new log is added, sometimes it works fine, but randomly it gets all glitched out, with multiple messages overlapping each other. Once that happens, if I scroll up, those overlapping messages will even jump around at random. Here's a video to illustrate:

The behavior is reproducible on Windows, Android, and iOS. It happens on the latest stable version of Avalonia, 11.0.10.

To Reproduce

See description

Expected behavior

No response

Avalonia version

11.0.10

OS

No response

Additional context

No response

[timunie]

please try 11.1 beta as well. Also looks like a custom theme, so best to check with simple sample and vanilla Avalonia

[jp2masa]

Duplicate of #14389?

[metal450]

please try 11.1 beta as well.

Hmm, actually seems to be fixed in the beta. Is the beta safe to use in a production app tho...?

[timunie]

I'd use it as we are close to 11.1 release. But better to test your App carefully before releasing it.

[metal450]

Unfortunately I haven't been able to get 11.1 to work in practice, because it requires .NET 8 (currently I'm on .net 7), and when I upgrade to .net 8, I can no longer initialize Maui.Essentials on iOS.

I'm assuming there's no way to either:

• Get this fix without upgrading to Avalonia 11.1, or
• Upgrade to 11.1 without having to upgrade to .NET 8, or
• I posted the Maui.Essentials issue here; have you seen this occur when upgrading to .Net 8? I know it isn't an Avalonia issue...but I'm kind of stuck if Avalonia is now requiring .Net 8. I included a repro project.

[metal450]

Just noticed 11.0.11 is out; seems to be fixed there :)