title: UIImageView get the position of the showing Image
body: <p>I have a UIImageView which shows an UIImage.</p>
  
  <p>The UIImage may change to other UIImage in different size, and the position and the size of the UIImage inside will change according according to it.</p>
  
  <p>My Problem is that i'm trying add a view that will be at the end of the UIImage (which change all the time) and all I can get is the frame of the UIImageView (which stay full screen all the time).</p>
  
  <p>How can i get the "frame" of current showing UIImage ?</p>