在 UILabel 中使用多个点击手势

Question

我正在创建一个 UILabel 需要有两种手势，单击和双击。

class ViewController: UIViewController, UIGestureRecognizerDelegate {

override func viewDidLoad() {
    super.viewDidLoad()
    view.addSubview(labelView)
    labelView.topAnchor.constraint(equalTo: view.topAnchor),
        quoteLabelView.leadingAnchor.constraint(equalTo: 
    view.leadingAnchor),
        quoteLabelView.trailingAnchor.constraint(equalTo: 
    view.trailingAnchor),
        quoteLabelView.bottomAnchor.constraint(equalTo: 
    view.topAnchor),
}

var labelView: UILabel = {
    let label = UILabel()
    label.translatesAutoresizingMaskIntoConstraints = false
    label.isUserInteractionEnabled = true
    let singleTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleSingleTap))
    let doubleTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleDoubleTap))
    singleTapGesture.numberOfTapsRequired = 1
    doubleTapGesture.numberOfTapsRequired = 2
    label.addGestureRecognizer(singleTapGesture)
    label.addGestureRecognizer(doubleTapGesture)
    return label
}()

}

我阅读了 apples 文档，其中提供了有关优先选择一种手势而不是另一种手势的信息，但我不知道如何将其应用于标签。 https://developer.apple.com/documentation/uikit/touches_presses_and_gestures/coordinating_multiple_gesture_recognizers/preferring_one_gesture_over_another

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer,
                       shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer) -> Bool {
    // Don't recognize a single tap until a double-tap fails.
    if gestureRecognizer == self.tapGesture &&
        otherGestureRecognizer == self.doubleTapGesture {
        return true
    }
    return false
}

有什么想法吗？

Answer 1

如果您想在标签声明中添加手势识别器，最好为单击和双击使用单独的函数：

class TestViewController: UIViewController {

    lazy var labelView: UILabel = {
        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        label.isUserInteractionEnabled = true

        let singleTapGesture = UITapGestureRecognizer(target: self, action: #selector(didSingleTap(_:)))
        singleTapGesture.numberOfTapsRequired = 1
        label.addGestureRecognizer(singleTapGesture)

        let doubleTapGesture = UITapGestureRecognizer(target: self, action: #selector(didDoubleTap(_:)))
        doubleTapGesture.numberOfTapsRequired = 2
        label.addGestureRecognizer(doubleTapGesture)

        singleTapGesture.require(toFail: doubleTapGesture)

        return label
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

        // add the labelView        
        view.addSubview(labelView)

        // set a couple properties
        labelView.text = "Tap or Double-Tap Me"
        labelView.textAlignment = .center
        labelView.backgroundColor = .yellow

        // constrain it to the view
        NSLayoutConstraint.activate([
            labelView.topAnchor.constraint(equalTo: view.topAnchor, constant: 200),
            labelView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            labelView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
        ])

    }

    @objc func didSingleTap(_ gesture: UITapGestureRecognizer) -> Void {
        print("Did Single Tap")
    }

    @objc func didDoubleTap(_ gesture: UITapGestureRecognizer) -> Void {
        print("Did Double Tap")
    }

}

Answer 2

正如您分享的 link 所说，您需要为手势识别器设置委托：

class ViewController: UIViewController, UIGestureRecognizerDelegate {

var singleTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleSingleTap))
var doubleTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleDoubleTap)) 

override func viewDidLoad() {
    super.viewDidLoad()
    view.addSubview(labelView)
    setupGestures()
    labelView.topAnchor.constraint(equalTo: view.topAnchor),
        quoteLabelView.leadingAnchor.constraint(equalTo: 
    view.leadingAnchor),
        quoteLabelView.trailingAnchor.constraint(equalTo: 
    view.trailingAnchor),
        quoteLabelView.bottomAnchor.constraint(equalTo: 
    view.topAnchor),
}

func setupGestures() {
    singleTapGesture.numberOfTapsRequired = 1
    singleTapGesture.delegate = self
    doubleTapGesture.numberOfTapsRequired = 2
    doubleTapGesture.delegate = self
    labelView.addGestureRecognizer(singleTapGesture)
    labelView.addGestureRecognizer(doubleTapGesture)
}

var labelView: UILabel = {
    let label = UILabel()
    label.translatesAutoresizingMaskIntoConstraints = false
    label.isUserInteractionEnabled = true
    return label
}()

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer,
                   shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer) -> Bool {
    // Don't recognize a single tap until a double-tap fails.
    if gestureRecognizer == self.tapGesture &&
        otherGestureRecognizer == self.doubleTapGesture {
        return true
    }
    return false
}
}

然后是你发的方法

此外，您需要能够访问手势，因此请将其从标签中删除。

在 UILabel 中使用多个点击手势

using multiple tap gestures with UILabel

uigesturerecognizer

ios

swift