2013-12-06 10:15:51.668 CodingForFun[4569:70b] nested push animation can result in corrupted navigation bar
2013-12-06 10:15:52.023 CodingForFun[4569:70b] Finishing up a navigation transition in an unexpected state. Navigation Bar subview tree might get corrupted.
在switch里少了break....
囧....