title: Xamarin.Froms throws CS0012 Error on accessing visibleBounds property
body: <p>I'm using Xamarin.Forms, but I get the <em>Error CS0012 The type ' Rect ' is defined in an assembly que is not referenced . You must add a reference to assembly ' System.Runtime.WindowsRuntime , Version = 4.0.0.0 , when I try to use visibleBounds</em></p>
  
  <p><a href="http://i.stack.imgur.com/aAPhd.jpg" rel="nofollow">Screenshot of the error message</a></p>