Bug: Accessing some of TaskbarIcon's properties results in an COMException

[myfix16]

Describe the bug

Accessing some of TaskbarIcon's properties, such as Icon, GeneratedIcon, Margin, etc., results in a System.Runtime.InteropServices.COMException.

Exception message:

An application calls an interface that has been marshaled for another thread

Steps to reproduce the bug

1. Create a sample WindowsAppSDK 1.2 packaged C# app
2. Add a windowless TaskbarIcon using the same method as this sample
3. Access TaskbarIcon's properties, for example,

TaskbarIcon icon = <Initialization>;
icon.GeneratedIcon.Text = "Test";

4. Observe the exception in a debug session.

Expected behavior

No exception should be thrown.

Screenshots

Exception details:

NuGet package version

H.NotifyIcon.WinUI 2.0.75
Microsoft.WindowsAppSDK 1.2.221209.1

Platform

WinUI

IDE

Visual Studio 2022

Windows Version

Windows 11

WindowsAppSDK Version

Other

WindowsAppSDK Type

Packaged

Manifest

No response

Additional context

No response

[myfix16]

The problem is resolved with the solution posted by @JasonWei512 in #54 (comment), quoted below:

Use a DispatcherQueue to execute UI related code on the main UI thread. Otherwise you may get an exception.

I recommend using the CommunityToolkit.WinUI nuget package's DispatcherQueueExtensions.EnqueueAsync.

using CommunityToolkit.WinUI;

class MyClass
{
    // Get a DispatcherQueue instance for later use. This has to be called on the UI thread,
    // but it can then be cached for later use and accessed from a background thread as well.
    private readonly DispatcherQueue dispatcherQueue = DispatcherQueue.GetForCurrentThread();

    // ...

    // Your tray icon event handler. This may not be called from the main UI thread
    private async void ExitApplicationCommand_ExecuteRequested(object? sender, EventArgs args)
    {
        // Execute some code on the target dispatcher queue
        await dispatcherQueue.EnqueueAsync(() =>
        {
            if (App.MainWindow.Visible)
            {
                // ...
            }
        });
    }
}