问题：

ios 如何定制 UIViewController 转场动画？ present  & pop / push & pop 动画

 

解决：

实现 UIViewControllerAnimatedTransitioning

navigationController.delegate = trans

toController.transitioningDelegate = trans

 

参考：

http://www.xiaoyaoli.com/?p=1271

https://developer.apple.com/reference/uikit/uiviewcontrolleranimatedtransitioning