ios - subview 不滚动，但滚动条快速滚动

Question

我正在以编程方式创建scrollView，但由于某些原因，我可以看到scrollView的滚动条，但 subview 没有滚动。在下面添加了我的代码

//create a closure for scroll view
    let vcScrollView: UIScrollView = {
        let scrollView = UIScrollView()
        scrollView.translatesAutoresizingMaskIntoConstraints = false
        scrollView.backgroundColor = UIColor.dark_background

        return scrollView
    }()

//create closure for dark view
    let darkView: UIView = {
        let view = UIView()
        view.backgroundColor = UIColor.black
        view.translatesAutoresizingMaskIntoConstraints = false
        return view
    }()

//create a closure for offer label
    let offerLabel: UILabel = {
        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        label.textColor = UIColor.white
        return label
    }()

override func viewDidLoad() {
        super.viewDidLoad()
        modalPresentationCapturesStatusBarAppearance = true

        view.addSubview(vcScrollView)
        setUpViews()


    }

func setUpViews(){
        //scrollView
        vcScrollView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
        vcScrollView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
        vcScrollView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
        vcScrollView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
        vcScrollView.contentSize.height = 1500

        //Dark view
        vcScrollView.addSubview(darkView)
        darkView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
        darkView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
        darkView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
        darkView.heightAnchor.constraint(equalToConstant: 130).isActive = true

        //Offer Label
        darkView.addSubview(offerLabel)
        offerLabel.text = selectedOffer
        offerLabel.font = UIFont(name: String.defaultFontR, size: 29)
        offerLabel.textAlignment = .center
        offerLabel.topAnchor.constraint(equalTo: darkView.topAnchor, constant: 95).isActive = true
        offerLabel.leadingAnchor.constraint(equalTo: darkView.leadingAnchor, constant: 20).isActive = true
        offerLabel.trailingAnchor.constraint(equalTo: darkView.trailingAnchor, constant: -20).isActive = true
    }

也将 ScrollView 添加为 View 的 subview 。提前致谢

Answer 1

问题是您的 ScrollView 的子级正在使用 View 的 anchor 。将它们切换为使用 scrollView 的 anchor 。此外，您可以使用宽度约束来代替尾随约束。这将允许它向上和向下滚动。

//Dark view
vcScrollView.addSubview(darkView)
darkView.leadingAnchor.constraint(equalTo: vcScrollView.leadingAnchor).isActive = true
darkView.topAnchor.constraint(equalTo: vcScrollView.topAnchor).isActive = true
darkView.widthAnchor.constraint(equalTo: vcScrollView.widthAnchor).isActive = true
darkView.heightAnchor.constraint(equalToConstant: 130).isActive = true

如果您想在 darkView 下包含 View ，则需要提供 subview 的底部 anchor 。