获取当前ViewController

iOS 获取窗口中当前视图根控制器与导航控制器
- (UIViewController *)currentViewController
{
    UIWindow *keyWindow  = [UIApplication sharedApplication].keyWindow;
    UIViewController *vc = keyWindow.rootViewController;
    while (vc.presentedViewController)
    {
        vc = vc.presentedViewController;

        if ([vc isKindOfClass:[UINavigationController class]])
        {
            vc = [(UINavigationController *)vc visibleViewController];
        }
        else if ([vc isKindOfClass:[UITabBarController class]])
        {
            vc = [(UITabBarController *)vc selectedViewController];
        }
    }
    return vc;
}

- (UINavigationController *)currentNavigationController
{
    return [self currentViewController].navigationController;
}

//获取当前控制器
- (UIViewController*)viewController {
    for (UIView* next = [self superview]; next; next = next.superview) {
        UIResponder* nextResponder = [next nextResponder];
        if ([nextResponder isKindOfClass:[UIViewController class]]) {
            return (UIViewController*)nextResponder;
        }
    }
    return nil;
}