如何以编程方式将多个UIViewControllers添加到UIScrollView

Question

在这里的好人的帮助下，我已经学会了如何将UIViewController添加到UIScrollView - 正确的方法。问题是，我需要添加多个视图控制器。我尝试创建一个UIViewControllers数组，然后使用for...in循环将控制器添加为子视图控制器，然后将其视图推送到滚动视图。这不起作用。

现在，我只在滚动视图中看到一个ViewController，第一个...任何人都可以告诉我我做错了什么？

请参阅我viewDidLoad()中的相关代码以及我设置用于创建相关对象的属性：

    @IBOutlet var contentScrollView: UIScrollView!
    var frame = CGRectMake(0, 0, 0, 0)
    var dataArray = [PostViewController]()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        var da = PostItem(text: "test 1", pic: "beans.jpg")
        var vc =  PostViewController(nibName:"PostViewController", bundle:nil)
        vc.text = da!.postText
        vc.image = da!.postImage
        self.dataArray.append(vc)

        da = PostItem(text: "test 2", pic: "coffeeCup.jpg")
        vc =  PostViewController(nibName:"PostViewController", bundle:nil)
        vc.text = da!.postText
        vc.image = da!.postImage
        self.dataArray.append(vc)

        da = PostItem(text: "test 2", pic: "coffeeMill.jpg")
        vc =  PostViewController(nibName:"PostViewController", bundle:nil)
        vc.text = da!.postText
        vc.image = da!.postImage
        self.dataArray.append(vc)

        //...

        for index in 0..<self.dataArray.count{
            self.frame.origin.y = self.contentScrollView.frame.size.height * CGFloat(index)
            self.frame.size = self.contentScrollView.frame.size
            self.contentScrollView.pagingEnabled = false
            let vc = self.dataArray[index]

            self.addChildViewController(vc)
            self.contentScrollView.addSubview(vc.view)

        }

        self.contentScrollView.contentSize = CGSizeMake(self.view.frame.size.width, CGFloat(self.dataArray.count) * self.contentScrollView.frame.height)
}