为什么我的vfl无法正常工作？

Question

我有以下代码，我试图实现添加到垂直滚动视图的动态图像。我想有它的约束，所以图像设置在scrollView的边框内。

然而结果是图像似乎保持原始大小（比滚动视图大，因此图像被裁剪）

以下是代码：

@IBOutlet weak var myScrollView: UIScrollView!
private let lettersModel:LettersModel = LettersModel();
private var imgs = [UIImageView]();

override func viewDidLoad() {
    super.viewDidLoad()

    myScrollView.backgroundColor = UIColor.brownColor()

    for var index=0; index<1; index++
    {

        let myImage:UIImage = UIImage(named: lettersModel.getLetterAt(index))!
        let myImageView:UIImageView = UIImageView()
        myImageView.image = myImage
        myImageView.contentMode = UIViewContentMode.ScaleAspectFit

        myScrollView.addSubview(myImageView)

        myImageView.translatesAutoresizingMaskIntoConstraints = false;

        myScrollView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-[myImageView]-|", options: [], metrics: nil, views:["myImageView":myImageView] ))

        imgs.append(myImageView)

    }

}

Answer 1

UIView内的

UIScrollView无法调整其父级的大小。{p> layoutSubviews您可以在UIScrollView中创建UIView并更新UIScrollView中的宽度，并在UIView中添加所有UIView。以下是如何执行此操作:(为此，您需要设置class MyScrollView : UIScrollView { let contentView = UIView() override init (frame : CGRect) { super.init(frame : frame) addSubview(contentView) } convenience init () { self.init(frame:CGRect.zero) } required init(coder aDecoder: NSCoder) { fatalError("This class does not support NSCoding") } override func layoutSubviews() { contentView.frame.size.width = frame.width contentView.frame.size.height = contentSize.height super.layoutSubviews() } } var myScrollView = MyScrollView(frame: CGRect(x: 0, y: 0, width: 400, height: 600)) var imgs = [UIImageView](); let myImage = UIImage(named: "achtergrond") let myImageView:UIImageView = UIImageView() myImageView.image = myImage myImageView.contentMode = UIViewContentMode.ScaleAspectFit myScrollView.contentSize.height = 1000 // <-- setting the contentSize myScrollView.contentView.addSubview(myImageView) // <-- You add the UIImageView to the contentView myImageView.translatesAutoresizingMaskIntoConstraints = false; myScrollView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-[myImageView]-|", options: [], metrics: nil, views:["myImageView":myImageView] )) imgs.append(myImageView) 的contentSize的高度，但您还必须设置此值以使其滚动。）

REQUEST_URI

Answer 2

您必须像下面一样激活它们，只需为您的实现编辑代码。

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