ios currentViewController

+ (UINavigationController*)currentNavigationViewController {
    
    UIViewController* currentViewController = [self currentViewController];
    return currentViewController.navigationController;
}

+ (UIViewController *)currentViewController {
    UIViewController *result = nil;
        UIWindow * window = [[UIApplication sharedApplication] keyWindow];
        if (window.windowLevel != UIWindowLevelNormal)
        {
            NSArray *windows = [[UIApplication sharedApplication] windows];
            for(UIWindow * tmpWin in windows)
            {
                if (tmpWin.windowLevel == UIWindowLevelNormal)
                {
                    window = tmpWin;
                    break;
                }
            }
        }
        UIView *frontView = [[window subviews] objectAtIndex:0];
        id nextResponder = [frontView nextResponder];
        
        if ([nextResponder isKindOfClass:[UIViewController class]])
            result = nextResponder;
        else
            result = window.rootViewController;
        
    return [self currentViewControllerFrom:result];
}

+ (UIViewController*)currentViewControllerFrom:(UIViewController*)viewController {
    
    if ([viewController isKindOfClass:[UINavigationController class]]) {
        
        UINavigationController* navigationController = (UINavigationController *)viewController;
        return [self currentViewControllerFrom:navigationController.viewControllers.lastObject];
        
    } else if([viewController isKindOfClass:[UITabBarController class]]) {
        
        UITabBarController* tabBarController = (UITabBarController *)viewController;
        return [self currentViewControllerFrom:tabBarController.selectedViewController];
        
    } else if(viewController.presentedViewController != nil) {
        
        return [self currentViewControllerFrom:viewController.presentedViewController];
        
    } else {
        
        return viewController;
        
    }
}