1) 打印出完整的视图层次结构
po [[UIWindow keyWindow] recursiveDescription]
2)检查视图控制器
po [[[UIWindow keyWindow] rootViewController] _printHierarchy]
1) 打印出完整的视图层次结构
po [[UIWindow keyWindow] recursiveDescription]
2)检查视图控制器
po [[[UIWindow keyWindow] rootViewController] _printHierarchy]