介绍

我正在创建一个使用自定义视图的应用程序，其中我有一个 UIStackView 来整理 5 个 UIControl。当用户点击其中一个 UIControl 时，下划线会变为动画，并在点击的 UIControl 下方滑动。

但是，由于某种原因，这些 UIControl 的方法/选择器不再被调用。我相信这与我将 Mac 更新到本周发布的 macOS（和 Xcode）更新（第 44 周）有关。 （从 swift 4.2 更新到 swift 4.2.1）。在更新之前，这个动画和选择器工作得很好。但我不确定。我现在完全陷入了我做错的事情中。

Context

• 我创建了一个游乐场并尽可能缩小了所有内容，但问题仍然存在。

• 我试图在我的全局范围内定义 UIStackViewSetupView类，但它不会改变任何东西。所以我相信这不是 stackView 或其子视图被释放的问题？

• 下面我提供了我的 UIControl 子类和我的SetupView我使用的（UIView 子类）。我已经创建了一个 Playground，因此您可以在 Xcode Playground 中复制粘贴来测试是否需要。

Question

• 为什么没有方法goalViewControlTapped(_ sender: SetupViewControl)接到电话吗？

Code

import UIKit
import PlaygroundSupport

class SetupViewControl: UIControl {

    let titleLabel : UILabel = {
        let lbl = UILabel()
        lbl.font = UIFont(name: "Futura", size: 14)
        lbl.textColor = .white
        lbl.backgroundColor = .clear
        lbl.textAlignment = .center
        lbl.translatesAutoresizingMaskIntoConstraints = false
        return lbl
    }()

    override init(frame: CGRect) {
        super.init(frame: frame)
        setupLabel()
        layer.cornerRadius = 5
    }

    fileprivate func setupLabel() {
        addSubview(titleLabel)
        titleLabel.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 5).isActive = true
        titleLabel.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -5).isActive = true
        titleLabel.centerYAnchor.constraint(equalTo: centerYAnchor).isActive = true
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override var isHighlighted: Bool {
        didSet {
            UIView.animate(withDuration: 0.12) {
                self.backgroundColor = self.isHighlighted ? UIColor.lightGray : UIColor.clear
            }
        }
    }
}

class SetupView: UIView {

    let dataModel : [String] = ["2 weeks", "1 month", "2 months", "6 months", "1 year"]
    var selectionLineCenterX : NSLayoutConstraint!

    let selectionLine = UIView()
    let labelZero = SetupViewControl()
    let labelOne = SetupViewControl()
    let labelTwo = SetupViewControl()
    let labelThree = SetupViewControl()
    let labelFour = SetupViewControl()
    let labelFive = SetupViewControl()

    lazy var controlArray = [self.labelZero, self.labelOne, self.labelTwo, self.labelThree, self.labelFour, self.labelFive]

    init(frame: CGRect, color: UIColor) {
        super.init(frame: frame)
        self.backgroundColor = color
        setupView()
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    fileprivate func setupView() {
        layer.cornerRadius = 0
        layer.borderColor = UIColor.black.cgColor
        layer.borderWidth = 1
        setupLabelText()
        setupControlsInStackView()
    }

    fileprivate func setupLabelText() {
        for num in 0...(dataModel.count - 1) {
            controlArray[num].titleLabel.text = dataModel[num]
        }
    }

    // let stackView = UIStackView(frame: .zero) I have tried to declare the stackView here but it doesn't fix my issue.
    func setupControlsInStackView() {
        var stackViewArray = [SetupViewControl]()
        for num in 0...(dataModel.count - 1) {
            controlArray[num].isUserInteractionEnabled = true
            controlArray[num].addTarget(self, action: #selector(goalViewControlTapped(_:)), for: .touchUpInside)
            stackViewArray.append(controlArray[num])
        }
        let stackView = UIStackView(arrangedSubviews: stackViewArray)
        stackView.alignment = .fill
        stackView.distribution = .fillEqually
        stackView.axis = .horizontal
        stackView.translatesAutoresizingMaskIntoConstraints = false
        addSubview(stackView)
        stackView.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 8).isActive = true
        stackView.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -8).isActive = true
        stackView.topAnchor.constraint(equalTo: topAnchor, constant: 15).isActive = true

        addSubview(selectionLine)
        selectionLine.backgroundColor = .white
        selectionLine.translatesAutoresizingMaskIntoConstraints = false
        selectionLine.heightAnchor.constraint(equalToConstant: 1).isActive = true
        selectionLine.topAnchor.constraint(equalTo: stackView.bottomAnchor).isActive = true
        selectionLine.widthAnchor.constraint(equalToConstant: 50).isActive = true
        selectionLineCenterX = selectionLine.centerXAnchor.constraint(equalTo: leadingAnchor, constant: -100)
        selectionLineCenterX.isActive = true
    }

    @objc fileprivate func goalViewControlTapped(_ sender: SetupViewControl) {
        print("This is not getting printed!!!")
        selectionLineCenterX.isActive = false
        selectionLineCenterX = selectionLine.centerXAnchor.constraint(equalTo: sender.centerXAnchor)
        selectionLineCenterX.isActive = true
        UIView.animate(withDuration: 0.25, delay: 0, usingSpringWithDamping: 0.8, initialSpringVelocity: 0.5, options: .curveEaseIn, animations: {
            self.layoutIfNeeded()
        }, completion: nil)
    }
}

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .white
        let testView = SetupView(frame: .zero, color: UIColor.blue)
        view.addSubview(testView)
        testView.translatesAutoresizingMaskIntoConstraints = false
        testView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
        testView.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
        testView.heightAnchor.constraint(equalToConstant: 100).isActive = true
        testView.widthAnchor.constraint(equalToConstant: 365).isActive = true
    }
}
// For live view in playground
let vc = ViewController()
vc.preferredContentSize = CGSize(width: 375, height: 812)
PlaygroundPage.current.liveView = vc

感谢您阅读我的问题。

请问您UIStackView当您打开视图调试器时显示为具有不明确的布局？如果是这样，可能会导致内部视图无法接收触摸事件。

您可以提供UIStackView与以下任一：

x and y仅约束

or

x, y, width and height.

在上述情况下height缺少约束。