http://www.mobinett.com/2013/08/19/ios7-ui-transition-porting-view-controller-layouts-ios6/
iOS 7 UI Transition – Porting View Controller Layouts from iOS 6,布布扣,bubuko.com
iOS 7 UI Transition – Porting View Controller Layouts from iOS 6
原文：http://www.cnblogs.com/nugao/p/3581741.html