Adding cancel and done buttons to a modal page

I want to display a modal page, like when you click the 'add event' button in the native iOS calendar app. In my modal page I want to display a TableView. This code deals with the navigation

  await Navigation.PushModalAsync (new MyModalPage ());

However, I can't find out how to add red Cancel and Done buttons to the top of the page. Anyone know how?

regards