title: Using Block Completion Handler in iOS 4 for animation
body: <p>I would like to animate my subviews movement when rotating the device, changing the alpha to 0, move the view to the new position and reset the alpha to 1.</p>
  
  <p>Using this code in <code>didRotateFromInterfaceOrientation</code> causes the view to flash and fade very quickly and then reappear. I would like to avoid this behaviour.</p>
  
  <pre><code>[UIView animateWithDuration:kAnimationDuration animations:^{
      anObject.alpha = 0.0;
      CGRect newFrame = anObject.frame;
      newFrame.origin.x = newX;
      newFrame.origin.y = newY;
      newFrame.size.width = newWidth;
      newFrame.size.height = newHeight;
      anObject.frame = newFrame;
  } completion:^ (BOOL finished){
      if (finished) {
          anObject.alpha = 1.0;
      }
  }];
  </code></pre>
  
  <p>Is there a way around this flashing?</p>
  
  <p>Thanks</p>