IOS status bar

- (BOOL)prefersStatusBarHidden; 

假设想利用UIApplication来管理状态栏。首先得改动Info.plist的设置

UIApplication *app = [UIApplication sharedApplication];
[app setStatusBarHidden:YES withAnimation:UIStatusBarAnimationFade];
[app setStatusBarStyle:UIStatusBarStyleLightContent animated:YES];
//    app.statusBarHidden = YES;
//    app.statusBarStyle = UIStatusBarStyleLightContent;