title: adding bounce effect to appearance of UIImageView
body: <p>How can I add a bounce effect when I am about to show an UIImageView as a subview? Do I have to use CoreAnimation to do this? My only guess right now is to use CAKeyframeAnimation, please let me know if there's a better way. Here's my current code:</p>
  
  <pre><code> CABasicAnimation * theAnimation=[CABasicAnimation animationWithKeyPath:@"transform.translation.y"];
      theAnimation.delegate = self;
      theAnimation.duration = 1.0;
      theAnimation.fromValue = [NSNumber numberWithFloat:notif.center.y];
      theAnimation.toValue = [NSNumber numberWithFloat:notif.center.y-20];
      theAnimation.repeatCount = 3;
  </code></pre>