获取手机当前显示的ViewController

//获取手机当前显示的ViewController
- (UIViewController*)currentViewController{
    UIViewController* vc = [UIApplication sharedApplication].keyWindow.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;
}