你可以通过window属性来检查

if(viewController.view.window){

// view visible

}else{

// no visible

}

我在uiviewcontroller。h中找到了这些函数。

/*
  These four methods can be used in a view controller's appearance callbacks to determine if it is being
  presented, dismissed, or added or removed as a child view controller. For example, a view controller can
  check if it is disappearing because it was dismissed or popped by asking itself in its viewWillDisappear:
  method by checking the expression ([self isBeingDismissed] || [self isMovingFromParentViewController]).
*/

- (BOOL)isBeingPresented NS_AVAILABLE_IOS(5_0);
- (BOOL)isBeingDismissed NS_AVAILABLE_IOS(5_0);

- (BOOL)isMovingToParentViewController NS_AVAILABLE_IOS(5_0);
- (BOOL)isMovingFromParentViewController NS_AVAILABLE_IOS(5_0);

也许上面的函数可以检测ViewController是否出现。

你想要使用UITabBarController的selectedViewController属性。所有附加到标签栏控制器的视图控制器都有一个tabBarController属性集，所以你可以在任何视图控制器的代码中:

if([[[self tabBarController] selectedViewController] isEqual:self]){
     //we're in the active controller
}else{
     //we are not
}

我需要这个来检查是否视图控制器是当前的视图控制器，我通过检查是否有任何呈现的视图控制器或通过导航器推送，我张贴它以防有人需要这样的解决方案:

if presentedViewController != nil || navigationController?.topViewController != self {
      //Viewcontroller isn't viewed
}else{
     // Now your viewcontroller is being viewed 
}

亮点:

window.isVisible

viewController.view.window?.isVisible ?? false

View (macOS):

extension NSViewController {
    var isOnScreen: Bool {
        return ( self.isViewLoaded && view.window != nil )
    }
}

XCode 6.4, iOS 8.4, ARC启用

显然有很多种方法。对我有效的方法如下:

@property(nonatomic, readonly, getter=isKeyWindow) BOOL keyWindow

这可以在任何视图控制器中以以下方式使用，

[self.view.window isKeyWindow]

如果你在-(void)viewDidLoad中调用这个属性，你得到0，然后如果你在-(void)viewDidAppear:(BOOL)animated后调用这个属性，你得到1。

希望这能帮助到一些人。谢谢!欢呼。