title: How to get the displayed image frame from UIImageView?
body: <p>I modify the UIImageView's contentMode property. So my image's frame is not equal to the frame of UIImageView. My problem is how to retrive the image's frame from UIImageView.</p>
  
  <p>As the following example, the orange rectangle is the UIImageView's border. It is obviously that the frame of image is not the same as UIImageView.</p>
  
  <p><img src="https://i.stack.imgur.com/Qp4Zq.png" alt="Figure 1"></p>