Xamarin Forms Parallax Scrolling

gistfile1.cs

public class DemoPage : ContentPage
	{
		public DemoPage ()
		{
			var image = new Image () {
				Source = "http://eric.polerecky.com/images/abstract-1.jpg", 
				VerticalOptions = LayoutOptions.Start, 
				Scale = 3, 
				AnchorY = 0
			};

			var grid = new Grid ();
			var scrollView = new ScrollView ();
			scrollView.Scrolled += (object sender, ScrolledEventArgs e) => {
				var imageHeight = image.Height * 3;
				var scrollRegion = grid.Height - scrollView.Height;
				var parallexRegion = imageHeight - scrollView.Height;
				image.TranslationY = scrollView.ScrollY - parallexRegion * (scrollView.ScrollY / scrollRegion);
			};

			scrollView.Content = grid;

			grid.Children.Add (image);

			StackLayout stackLayout = new StackLayout () {
				HorizontalOptions = LayoutOptions.Center
			};

			for (int i = 0; i < 50; i++) {
				stackLayout.Children.Add (new Label () { 
					Text = "This is some text to scroll", 
					FontSize = 24,
					HeightRequest = 50
				});
			}

			grid.Children.Add (stackLayout);

			this.Content = scrollView;
		}
	}