iOS获取屏幕最上层的ViewController

实际开发中，时长需要获取屏幕最上层的ViewController，以下代码是对实现此需求的简单代码封装。

PS:以下代码被封装为UIApplication类的分类

 `
 //获取rootViewController
 
 
 
  
(UIViewController )rootViewController{
 UIWindow window = [UIApplication sharedApplication].keyWindow;
 return window.rootViewController;
 }
 `
 

 `
 //获取Window当前显示的ViewController
 
 
 
  
 
(UIViewController)currentViewController{
 UIViewController vc = [UIApplication rootViewController];
 
while (1) {
 if ([vc isKindOfClass:[UITabBarController class]]) {
 vc = ((UITabBarController*)vc).selectedViewController;
 }
 
  if ([vc isKindOfClass:[UINavigationController class]]) {
      vc = ((UINavigationController*)vc).visibleViewController;
  }
  
  if (vc.presentedViewController) {
      vc = vc.presentedViewController;
  }else{
      break;
  }
 
}
 
return vc;
 }
 
 
 
 
 
`