title: Make subview of a UIScrollView fixed while the other subviews scrollable
body: <p>I want to make a View with three subviews stacked on top of each other with the middle subview scrollable with the others fixed. </p>
  
  <p>How can I achieve this programmatically? I have tried</p>
  
  <ul>
  <li>to set the contentsize of the root view to the size of the scrollable view but that makes all the views scroll.</li>
  </ul>
  
  <p>-set the contentsize of the middle subview without setting any property for the root view but that makes all the views unscrollable.</p>
  
  <p>Please help. I am new to iOS.</p>
  
  <p>Thanks in advance</p>