这对于从任何根视图控件中找到top viewcontroller1非常有效

+ (UIViewController *)topViewControllerFor:(UIViewController *)viewController
{
    if(!viewController.presentedViewController)
        return viewController;
    return [MF5AppDelegate topViewControllerFor:viewController.presentedViewController];
}

/* View Controller for Visible View */

AppDelegate *app = [UIApplication sharedApplication].delegate;
UIViewController *visibleViewController = [AppDelegate topViewControllerFor:app.window.rootViewController]; 

斯威夫特5

试试这个

let topVisibleVC = UIApplication.shared.keyWindow?.rootViewController?.visibleViewController

之前的答案似乎不能处理rootController是UITabBarController或UINavigationController的情况。

下面是swift中适用于这些情况的函数:

func getCurrentView() -> UIViewController?
{
    if let window = UIApplication.sharedApplication().keyWindow, var currentView: UIViewController = window.rootViewController
    {
        while (currentView.presentedViewController != nil)
        {
            if let presented = currentView.presentedViewController
            {
                currentView = presented
            }
        }

        if currentView is UITabBarController
        {
            if let visible = (currentView as! UITabBarController).selectedViewController
            {
                currentView = visible;
            }
        }

        if currentView is UINavigationController
        {
            if let visible = (currentView as! UINavigationController).visibleViewController
            {
                currentView = visible;
            }
        }

        return currentView
    }

    return nil
}

下面两个函数可以帮助在视图控制器堆栈中找到topViewController。以后可能需要自定义，但是对于这段代码来说，理解topViewController或viewcontroller堆栈的概念非常棒。

- (UIViewController*)findTopViewController {

  id  topControler  = [self topMostController];

  UIViewController* topViewController;
  if([topControler isKindOfClass:[UINavigationController class]]) {
        topViewController = [[(UINavigationController*)topControler viewControllers] lastObject];
   } else if ([topControler isKindOfClass:[UITabBarController class]]) {
        //Here you can get reference of top viewcontroller from stack of viewcontrollers on UITabBarController
  } else {
        //topController is a preented viewController
        topViewController = (UIViewController*)topControler;
  }
    //NSLog(@"Top ViewController is: %@",NSStringFromClass([topController class]));
    return topViewController;
}

- (UIViewController*)topMostController
{
    UIViewController *topController = [UIApplication sharedApplication].keyWindow.rootViewController;

    while (topController.presentedViewController) {
        topController = topController.presentedViewController;
    }
    //NSLog(@"Top View is: %@",NSStringFromClass([topController class]));
    return topController;
}

你可以使用[viewController Class]方法找出一个viewController的类的类型。

我最近在我的一个项目中遇到了这种情况，当网络状态发生变化时，需要显示一个通知视图，无论显示的控制器是什么，无论类型是什么(UINavigationController，经典控制器或自定义视图控制器)。

所以我刚刚发布了我的代码，这很简单，实际上是基于一个协议，所以它对每种类型的容器控制器都是灵活的。 它似乎与上一个答案有关，但方式更加灵活。

你可以从这里获取代码:PPTopMostController

并得到最顶级的控制器使用

UIViewController *c = [UIViewController topMostController];

这是对Eric的回答的改进:

UIViewController *_topMostController(UIViewController *cont) {
    UIViewController *topController = cont;

    while (topController.presentedViewController) {
        topController = topController.presentedViewController;
    }

    if ([topController isKindOfClass:[UINavigationController class]]) {
        UIViewController *visible = ((UINavigationController *)topController).visibleViewController;
        if (visible) {
            topController = visible;
        }
    }

    return (topController != cont ? topController : nil);
}

UIViewController *topMostController() {
    UIViewController *topController = [UIApplication sharedApplication].keyWindow.rootViewController;

    UIViewController *next = nil;

    while ((next = _topMostController(topController)) != nil) {
        topController = next;
    }

    return topController;
}

UIViewController *cont是一个辅助函数。

现在你所需要做的就是调用topMostController()和最顶端的UIViewController应该被返回!