// This should be called whenever the return values for the view controller's status bar attributes have changed. If it is called from within an animation block, the changes will be animated along with the rest of the animation block.
- (void)setNeedsStatusBarAppearanceUpdate NS_AVAILABLE_IOS(7_0) __TVOS_PROHIBITED;
如何运用“高内聚，低耦合”的架构思想设计应用