Xamarin Blueprints

Building a VisualElementRenderer for iOS

To handle native touch events on iOS, we are going to build a VisualElementRenderer. These work similar to CustomRenderers, but instead of rendering and replacing the entire control, we are able to render specific attributes, so we are able to attach native attributes to a Xamarin.Forms view.

Let's start with adding a new folder inside the Renderers folder called FocusView. Add in a new file called FocusViewRendererTouchAttribute.cs and implement the following:

public class FocusViewRendererTouchAttribute : VisualElementRenderer<FocusView> { public override void TouchesBegan (NSSet touches, UIEvent evt) { base.TouchesBegan (touches, evt); FocusView focusView = ((FocusView)this.Element); UITouch touch = touches.AnyObject ...