Toast/Notification global Trigger

[nadirvishun]

In the example, there is a strong dependency on the view layer TopLevel.GetTopLevel(this) to ensure that the popup appears on top.

Ursa.Avalonia/demo/Ursa.Demo/Pages/ToastDemo.axaml.cs

Lines 19 to 31 in 1d0bfe9

	protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
	{
	base.OnAttachedToVisualTree(e);
	var topLevel = TopLevel.GetTopLevel(this);
	_viewModel.ToastManager = new WindowToastManager(topLevel) { MaxItems = 3 };
	}
	protected override void OnDetachedFromVisualTree(VisualTreeAttachmentEventArgs e)
	{
	base.OnDetachedFromVisualTree(e);
	_viewModel.ToastManager?.Uninstall();
	}
	}

However, I am currently using HttpClient to request API interfaces. When the API interface returns an error, I want to globally toast a prompt (not in ViewModels, but in a common method encapsulated in a separate class DelegatingHandler). What should I do in this case?
At present, the only method I can think of is to use WeakReferenceMessenger for message passing, but is there a more convenient method?

[rabbitism]

I think for now WeakReferenceMessage is the correct way to go. But let's leave this issue open for a while and let me think if there is a better way.