参考原文:https://www.cnblogs.com/hualuoshuijia/p/6845636.html
基本用法为
[self beginAppearanceTransition:YES animated:NO];//调用viewWillAppear
[self endAppearanceTransition];//调用viewDidAppear
[self beginAppearanceTransition:NO animated:NO];//调用viewWillDisappear