최상위 View Controller 가져오기

+ (UIViewController*)topMostViewController {

    UIViewController *topMostViewController = nil;

    

    UIViewController *rootViewController = [UIApplication sharedApplication].keyWindow.rootViewController;

    if ([rootViewController isKindOfClass:[UINavigationController class]]) {

        UINavigationController* navigationController = (UINavigationController*)rootViewController;

        topMostViewController = navigationController.visibleViewController;

    } else if (rootViewController.presentedViewController) {

        topMostViewController = rootViewController.presentedViewController;

    } else if ([rootViewController isKindOfClass:[UITabBarController class]]) {

        UITabBarController* tabBarController = (UITabBarController*)rootViewController;

        topMostViewController = tabBarController.selectedViewController;

    } else

        topMostViewController = rootViewController;

    

    return topMostViewController;

}