Issue with Async / Await method along with Choosers and Launchers

Question

I added a the following extension method for photo chooser task and camera chooser task.

public static Task<TTaskEventArgs> ShowAsync<TTaskEventArgs>(this ChooserBase<TTaskEventArgs> chooser) where TTaskEventArgs : TaskEventArgs
{
    var taskCompletionSource = new TaskCompletionSource<TTaskEventArgs>();

    EventHandler<TTaskEventArgs> completed = null;

    completed = (s, e) =>
    {
        chooser.Completed -= completed;

        taskCompletionSource.SetResult(e);
    };

    chooser.Completed += completed;
    chooser.Show();

    return taskCompletionSource.Task;
}

And I invoked this method in my button click like this,

var photoResult = await new PhotoChooserTask().ShowAsync();
if (photoResult.TaskResult == TaskResult.OK)
{
    // set the photo to image source.
}

After adding this every thing is working fine, But my issue is that while the time of invoking task by setting tombstone mode on, The code after my await is not executing (ie the completed event). How i can tackle this situation, I am expecting an answer that solve my issue on the above mentioned implementation(async / await). Not expecting the answer of registering event in the constructor.

Answer 1

I see you're following my article for this, it just turns out I forgot that my current solution doesn't work for tombstoning, as pointed out by someone in the article comments.

I'm preparing a fix for this, and I'll update the thread once I got it ready!