title: How to animate UIView transform sequence like scaling then rotating in iOS?
body: <p>I wonder how to make a UIView animation that first scale to size and rotate that size instead of rotating on the original size?</p>
  
  <p>I've tried a lot of ways like wrapping UIView animation in the completion of a UIView animation, using UIView animateKeyframes and so on.</p>
  
  <p>However, I can't build a animation like it perfectly, please give me hints or keywords to search, thanks!</p>