从objC访问swift属性

- (void) tapGesture: (id)sender
{
    UITapGestureRecognizer *gesture = (UITapGestureRecognizer *) sender;
    NSInteger userID = gesture.view.tag;

    UIStoryboard* storyboard = [UIStoryboard storyboardWithName:@"Main"
                                                         bundle:nil];
    OthersProfile *vc = (OthersProfile*)[storyboard instantiateViewControllerWithIdentifier:@"othersprofile"];
    NSString *strUserID = [NSString stringWithFormat:@"%ld", (long)userID];

    vc.userID = strUserID;
    [self.viewController.navigationController pushViewController:vc
                                                        animated:YES];
}

它曾经与Xcode 8 / Swift 3一起使用，但似乎Xcode 9和swift 4出现了问题。

我有属性userID找不到错误。

在Swift文件中：

var userID : String = ""
override func viewDidLoad() {
    print(userID) //no value here
}

有任何想法吗？