Xcode 9 Swift 4 Playgrounds UIGestureRecognizer 不工作

Question

最近，我开始着手 WWDC 2018 提交。出于预期，我在一个 swift playground 文件中开始了我的项目（Apple 通常不接受应用程序提交）。大约两个月前，我将 Xcode 更新到了 9.2 版（9C40b）。这样做之后，我意识到我的手势识别器并没有在我的实时视图上工作。一切都在实时视图助手窗口上完美呈现和显示，但我的手势识别器根本没有响应。有没有人遇到过类似的问题，有没有人能够在 Xcode 9 中使用 Swift 4 的 Swift Playgrounds（我在下面附上了我的代码以供参考）？

//: A UIKit based Playground for presenting user interface

import UIKit
import PlaygroundSupport

class HomeViewController : UIViewController, UIGestureRecognizerDelegate {
    let cardViewOne = UIView()
    let cardButtonOne = UIButton()

    let cardViewTwo = UIView()
    let cardButtonTwo = UIButton()

    let cardViewThree = UIView()
    let cardButtonThree = UIButton()

    let cardViewControllerTitleLabel = UILabel()

    override func loadView() {
        let view = UIView()
        view.backgroundColor = .white

        //Card One

        cardViewOne.frame = CGRect(x: 0, y: 218, width: 375, height: 480)
        cardViewOne.backgroundColor = #colorLiteral(red: 1, green: 0.1058823529, blue: 0.3607843137, alpha: 1)
        cardButtonOne.frame = CGRect(x: 0, y: 0, width: 375, height: 47)
        cardButtonOne.backgroundColor = UIColor(red:0.90, green:0.10, blue:0.31, alpha:0.0)
        cardButtonOne.setTitle("About", for: .normal)
        cardButtonOne.titleLabel?.font = UIFont(name: "Avenir-Black", size: 18)

        cardViewOne.layer.shadowColor = UIColor.black.cgColor
        cardViewOne.layer.shadowOpacity = 0.25
        cardViewOne.layer.shadowOffset = CGSize.zero
        cardViewOne.layer.shadowRadius = 40
        cardViewOne.layer.shadowPath = UIBezierPath(rect: cardViewOne.bounds).cgPath

        //Card Two

        cardViewTwo.frame = CGRect(x: 0, y: 164, width: 375, height: 480)
        cardViewTwo.backgroundColor = #colorLiteral(red: 0.8965349741, green: 0.0931719053, blue: 0.3287236417, alpha: 1)
        cardButtonTwo.frame = CGRect(x: 0, y: 0, width: 375, height: 47)
        cardButtonTwo.backgroundColor = UIColor(red:0.90, green:0.10, blue:0.31, alpha:0.0)
        cardButtonTwo.setTitle("Mix", for: .normal)
        cardButtonTwo.titleLabel?.font = UIFont(name: "Avenir-Black", size: 18)

        cardViewTwo.layer.shadowColor = UIColor.black.cgColor
        cardViewTwo.layer.shadowOpacity = 0.25
        cardViewTwo.layer.shadowOffset = CGSize.zero
        cardViewTwo.layer.shadowRadius = 40
        cardViewTwo.layer.shadowPath = UIBezierPath(rect: cardViewTwo.bounds).cgPath


        //Card Three

        cardViewThree.frame = CGRect(x: 0, y: 109, width: 375, height: 480)
        cardViewThree.backgroundColor = #colorLiteral(red: 0.8446810233, green: 0.08778301191, blue: 0.3097108647, alpha: 1)
        cardButtonThree.frame = CGRect(x: 0, y: 0, width: 375, height: 47)
        cardButtonThree.backgroundColor = UIColor(red:0.90, green:0.10, blue:0.31, alpha:0.0)
        cardButtonThree.setTitle("Experiment", for: .normal)
        cardButtonThree.titleLabel?.font = UIFont(name: "Avenir-Black", size: 18)

        cardViewThree.layer.shadowColor = UIColor.black.cgColor
        cardViewThree.layer.shadowOpacity = 0.25
        cardViewThree.layer.shadowOffset = CGSize.zero
        cardViewThree.layer.shadowRadius = 40
        cardViewThree.layer.shadowPath = UIBezierPath(rect: cardViewThree.bounds).cgPath

        cardViewControllerTitleLabel.text = "Vibe"
        cardViewControllerTitleLabel.frame = CGRect(x: 158, y: 20, width: 81, height: 34)
        cardViewControllerTitleLabel.font = UIFont(name: "Avenir-Black", size: 32)
        cardViewControllerTitleLabel.textColor = #colorLiteral(red: 1, green: 0.1215686275, blue: 0.3529411765, alpha: 1)

        //ViewController Title

        cardViewOne.layer.zPosition = 3
        cardViewTwo.layer.zPosition = 2

        //z-index adjustment

        view.addSubview(cardViewOne)
        view.addSubview(cardViewTwo)
        view.addSubview(cardViewThree)
        cardViewOne.addSubview(cardButtonOne)
        cardViewTwo.addSubview(cardButtonTwo)
        cardViewThree.addSubview(cardButtonThree)
        view.addSubview(cardViewControllerTitleLabel)
        self.view = view
    }

    override func viewDidLoad() {
        let tap = UITapGestureRecognizer(target: self, action: #selector(handleTap))
        tap.delegate = self
        cardButtonTwo.addGestureRecognizer(tap)

        print("Gesture recognizer added")

        self.navigationController?.isNavigationBarHidden = true
    }

    @objc func handleTap(sender: UITapGestureRecognizer? = nil) {
        let detail = TestViewController()
        navigationController?.pushViewController(detail, animated: true)
    }
}

class TestViewController: UIViewController {

}

let root = HomeViewController()
let nav = UINavigationController(rootViewController: root)
// Present the view controller in the Live View window
PlaygroundPage.current.liveView = nav

Answer 1

您在卡片视图中使用了不正确的高度值。
将高度值更改为较小的值 47 有效：

cardViewOne.frame = CGRect(x: 0, y: 218, width: 375, height: 47)
cardViewTwo.frame = CGRect(x: 0, y: 164, width: 375, height: 47)
cardViewThree.frame = CGRect(x: 0, y: 109, width: 375, height: 47)

另外，因为cardButtonTwo 是UIButton，所以您不需要使用UITapGestureRecognizer。您可以简单地为touchUpInside 事件添加目标。

override func viewDidLoad() {
        cardButtonTwo.addTarget(self, action: #selector(HomeViewController.handleTap(sender:)), for: .touchUpInside)
        self.navigationController?.isNavigationBarHidden = true
    }