App.UnhandledException doesn't work at all

Describe the bug

Hi, how can I show the message when an application was crashed? The App.UnhandledException event doesn’t work. I’ve attached the sample. Also, I’ve found the issue https://github.com/microsoft/microsoft-ui-xaml/issues/5221 but in my case, it doesn’t catch any exceptions from the main thread. Same issue on WindowsAppSDK 1.0 preview 2

Steps to reproduce the bug

App.xaml.cs

    public partial class App : Application {
        public App() {
            UnhandledException += App_UnhandledException;
            this.InitializeComponent();
        }

        async void App_UnhandledException(object sender, Microsoft.UI.Xaml.UnhandledExceptionEventArgs e) {
            var dialog = new Windows.UI.Popups.MessageDialog(e.Exception.ToString());
            await dialog.ShowAsync();
        }

        protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args) {
            m_window = new MainWindow();
            m_window.Activate();
        }

        private Window m_window;
    }

MainWindow.xaml.cs

    public sealed partial class MainWindow : Window {
        public MainWindow() {
            this.InitializeComponent();
        }

        void myButton_Click(object sender, RoutedEventArgs e) {
            throw new ArgumentException("test");
        }
    }

Expected behavior

No response

Screenshots

https://i.imgur.com/WnHKKnV.gif

NuGet package version

WinUI 3 - Windows App SDK 0.8: 0.8.0 (If you’re seeing your issue in older previews of WinUI 3, please try this release)

Windows app type

• UWP
• Win32

Device form factor

Desktop

Windows version

May 2020 Update (19041)

Additional context

App3.zip

[Scottj1s]

App.UnhandledException fix will be available in Windows App SDK 1.2 Preview 2

[JohnnyWestlake]

UnhandledException is a bit of a misnomer… It is actually only thrown when something in the framework raises an error during Frame.Navigate, the name is quite bad but this is expected behavior.

That doesn’t sound correct 🤔 A UWP app would catch the majority of CLR and WinRT errors in the above in the App.UnhandledException handler no problem ignoring exceptions thrown in Tasks (in fact, I’ve just tried the above and it works as expected in UWP), and Frame navigation failures would probably bubble up Frame.NavigationFailed event. I would expect WinUI to behave similarly?