Terminating app due to uncaught exception ‘NSUnknownKeyException‘, reason: ‘[setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key backButton.‘
跳转问题，直接present到另一个ViewController上
Warning: Attempt to present on whose view is not in the window hierarchy!
原文：http://www.cnblogs.com/hanyutong/p/4427645.html