title: iphone scrollview and imageview autoresize
body: <p>I am using xcode 4.3.2. </p>
  
  <p>I have an <code>imageView</code> inside a <code>scrollView</code>, with the <code>contentMode</code> for both set as aspect fill.</p>
  
  <p>My problem is after I rotate the orientation, the screen focuses on the center of the image. </p>
  
  <p>When I scroll down there is a blank part under the image. 
  When I try to scroll up, it bounce me back, so actually I cannot stay at the top of <code>scrollView</code></p>
  
  <p>I set the <code>contentsize</code> of the scroll view to the size of the actual image showed on phone(not the original image size), </p>
  
  <p>The origin of both of the frames are 0, 0 so anyone can help resolve this issue when i rotate the phone.</p>