ViewController委托

Question

是否可以从appDelegate访问ViewController的方法，就像可能与以下代码相反：？

AppDelegate *ad = (AppDelegate *) [[UIApplication sharedApplication] delegate];

当我尝试

时

ViewController *vc = (ViewController *) [[UIApplication sharedApplication] delegate];

我收到错误...

谢谢！

Answer 1

在AppDelegate中，假设viewController是您的rootViewController，您可以通过以下方式获取堆栈中所有视图控制器的列表：

NSLog(@"List of current active view controllers:%@", self.viewController.navController.viewControllers);

访问viewControllers中的特定视图控制器：

[[self.viewController.navController.viewControllers objectAtIndex:i] someMethodOfThatViewController]; 

Answer 2

ViewController *vc = (ViewController *)[UIApplication sharedApplication].keyWindow.rootViewController;

或者您的代表是否具有属性

YourAppDelegate *ad = (YourAppDelegate*)[UIApplication sharedApplication].delegate;
ViewController *vc = ad.yourViewControllerProperty;