如何防止 UITableViewCell 内的手势干扰 UITableView 的滚动？

Question

我觉得这个问题之前已经被问过很多次了，但是我已经找了好几天了，找不到有效的解决方案。在 Swift 4 中，我有一个 UITableView，其中每个 UITableViewCell 里面都有可触摸的 UIView。这个 UIView 附加了一个 UILongPressGestureRecognizer ，它会影响其按下状态并在按下时导航到另一个屏幕。所有的行都相对靠近，不幸的是，为了启动平移手势来滚动 UITableView，您必须按下列表项，这会触发其手势识别器并立即离开页面。

原来，你不能按下 UITableViewCell 来触发滚动，所以我在我的 UIView 中设置了手势委托并添加了这个功能：

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
    return true
}

因此导致了我目前遇到的问题。这是我在 UITableViewCell 中使用的自定义 UIView 类：

import Foundation
import UIKit

protocol ItemViewDelegate: AnyObject {
    func tapped()
}

class ItemView: UIView, UIGestureRecognizerDelegate {
    weak var delegate: ItemViewDelegate?
    var parent: UIViewController?

    override init(frame: CGRect) {
        super.init(frame: frame)
        self.initializeGestureRecognition()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.initializeGestureRecognition()
    }

    lazy var animator: UIViewPropertyAnimator = {
        let cubicParameters = UICubicTimingParameters(controlPoint1: CGPoint(x: 0, y: 0.5), controlPoint2: CGPoint(x: 1.0, y: 0.5))
        let animator = UIViewPropertyAnimator(duration: 0.1, timingParameters: cubicParameters)

        animator.isInterruptible = true

        return animator
    }()

    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return true
    }

    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        if (type(of: otherGestureRecognizer) == UIPanGestureRecognizer.self) {
            return true
        }

        return false
    }

    private func initializeGestureRecognition() {
        let tapRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(self.handleTap(from:)))

        tapRecognizer.minimumPressDuration = 0
        tapRecognizer.delegate = self
        tapRecognizer.cancelsTouchesInView = false

        self.isUserInteractionEnabled = true
        self.addGestureRecognizer(tapRecognizer)
    }

    private func tapped() {
        guard let delegate = self.delegate else {
            return
        }

        delegate.tapped()
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        self.roundCorners(radius: 4)
        self.addShadow(opacity: 0.06, radius: 4)
    }

    @objc func handleTap(from recognizer: UITapGestureRecognizer) {
        switch recognizer.state {
        case .began:
            if animator.isRunning {
                animator.stopAnimation(true)
            }

            animator.addAnimations {
                self.transform = CGAffineTransform(scaleX: 0.98, y: 0.98)
            }

            animator.startAnimation()
        case .ended:
            if animator.isRunning {
                animator.stopAnimation(true)
            }

            animator.addAnimations {
                self.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
            }

            animator.startAnimation()

            self.tapped()
        default:
            break
        }
    }
}

我认为 shouldRequireFailureOf 覆盖肯定会起作用，正如 Apple 的文档所暗示的那样，但我现在已经尝试了几乎所有方法，并且正在拔头发。任何帮助，将不胜感激。谢谢！

Answer 1

你可以在包含 tableView 的 VC 中定义这个 var

var isScrolling = false

//

class ViewController: UIViewController , UIScrollViewDelegate

//

func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {

    isScrolling = true

}

func scrollViewDidScroll(_ scrollView: UIScrollView) {

    isScrolling = false

}

//

在单元格内读取这个值

@objc func handleTap(from recognizer: UITapGestureRecognizer) {

   if parentVc.isScrolling {  return  }

    .....
}