AsyncAnimate.cs

Task Animate (double duration, Action animation)
{
	var complete = new TaskCompletionSource<object> ();
	UIView.Animate (duration, () => animation (), () => {
		complete.TrySetResult (null);
	});
	return complete.Task;
}

async void Dismiss ()
{
	await Animate (0.2, () => {
		ControlView.Alpha = 0;
		CoverView.Frame = CoverOrigin;
		BackgroundView.Alpha = 1;
	});

	// Notify listeners so we can be fully dismissed
	Dismissed ();
}

public override async void ViewDidAppear (bool animated)
{
	ControlView.Alpha = 0;
	CoverView.Frame = CoverOrigin;
	BackgroundView.Alpha = 1;

	await Animate (0.2, () => {
		CoverView.Frame = CoverDestination;
		BackgroundView.Alpha = 0;
	});

	await Animate (0.2, () => {
		ControlView.Alpha = 1;
	});

	base.ViewDidAppear (false);
}