title: Animation block cannot resize UiView, but can move it
body: <p>I have a UIView on top of my appdelegate window.
  When I try to resize it to make it disappear, the animation doesn't work.</p>
  
  <p><strong>TLDR</strong> : cannot resize a UIView with UIAnimation block, but can move it</p>
  
  <pre><code>[UIView animateWithDuration:0.3
                        delay:0
                      options: UIViewAnimationCurveEaseIn
                   animations:^{ 
                       CGRect frame = viewMore.frame;
                       frame.size.height = 0;
                       viewMore.frame = frame;
  
                   } 
                   completion:^(BOOL finished){
  
                   }];
  </code></pre>
  
  <p>But, if I want to move the view, using this code, it works like charm.
  Example :</p>
  
  <pre><code>[UIView animateWithDuration:0.3
                        delay:0
                      options: UIViewAnimationCurveEaseIn
                   animations:^{ 
                      CGPoint centerMore =    viewMore.center;
                       centerMore.y += viewMore.frame.size.height;
                       viewMore.center = centerMore;
  
  
                   } 
                   completion:^(BOOL finished){
  
  
                   }];
  </code></pre>
  
  <p>viewMore has 2 UIButton subviews.
  The same code works to resize a UIWebView
  There are something that I don't understand. 
  You are my only hope (well no, you're not :) )</p>