How to await an event click [duplicate]

Answer 1

This is the fix for my initial code, that makes it work as expected. I had to define a closure for the callback

AsyncCallback callback;

Then I had to pass the callback to the closure from the beginMethod:

private IAsyncResult beginMethod(AsyncCallback callback, object state)
{
    this.callback = callback;
    return Task.FromResult(true);
}

and finally invoke it from the event (i.e. the Command method in the MVVM for WPF)

private async void RunNext()
{
    IsBusy = true;
    ProgressMessage = "Wait 10 seconds...";
    await workToDo();
    ProgressMessage = "Work done!";
    IsBusy = false;
    if (callback != null)
    {
        callback.Invoke(Task.FromResult(true));
    }
}