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在Swift 3中UITableViewCell的单击和双击

swiftuitableviewswift3uitapgesturerecognizer
5
我在 TableViewCell 上使用了故事板转场，我在 didSelectRowAt 方法中使用它来在单元格点击时转到另一个 VC。现在我添加了双击 TapGestureRecognizer 来处理单元格上的双击。问题是单击时转场已经执行了，而双击不起作用。当单击在单元格之外时，双击可以正常工作。有没有可能通过我的代码解决这个问题？或者我需要删除转场，并分别处理单击和双击。谢谢任何建议。
override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    let doubleTap = UITapGestureRecognizer(target: self, action: #selector(handleDoubleTap))
    doubleTap.numberOfTapsRequired = 2
    view.addGestureRecognizer(doubleTap)
}

func handleDoubleTap(recognizer: UIGestureRecognizer) {
    let p = recognizer.location(in: tableView)

    let indexPath = tableView.indexPathForRow(at: p)

    if let _ = indexPath {
        tableView.deselectRow(at: indexPath!, animated: true)
        update(index: (indexPath?.row)!, isFinished: true)
    }

    print ("doubke")
}


override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if (segue.identifier == "showSingleTask") {
        if let indexPath = tableView.indexPathForSelectedRow {
            let nav = segue.destination as! UINavigationController
            let destinationVC = nav.topViewController as! ShowTaskVC
            destinationVC.singleTask = tasks[indexPath.row]
        }
    }
}

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

    tableView.deselectRow(at: indexPath as IndexPath, animated: true)
    self.selectedTask = tasks[indexPath.row]
}
所以我有一个问题.. 你想双击单元格以调用segue吗？也许提供更多细节会有所帮助。 - J Arango
禁用单元格的默认轻击，并添加一个单击手势，就像您添加双击一样。 - Bista
@JArango 我想要在单元格上双击调用handleDoubleTap方法，在单元格上单击执行segue，我想知道是否可以使用didSelectRowAt方法实现，还是需要像上面建议的那样添加单击手势。 - bzadm
3个回答
15

详情

  • Xcode 10.2.1 (10E1001)，Swift 5

解决方案

protocol MultiTappableDelegate: class {
    func singleTapDetected(in view: MultiTappable)
    func doubleTapDetected(in view: MultiTappable)
}

class ThreadSafeValue<T> {
    private var _value: T
    private lazy var semaphore = DispatchSemaphore(value: 1)
    init(value: T) { _value = value }
    var value: T {
        get {
            semaphore.signal(); defer { semaphore.wait() }
            return _value
        }
        set(value) {
            semaphore.signal(); defer { semaphore.wait() }
            _value = value
        }
    }
}

protocol MultiTappable: UIView {
    var multiTapDelegate: MultiTappableDelegate? { get set }
    var tapCounter: ThreadSafeValue<Int> { get set }
}

extension MultiTappable {
    func initMultiTap() {
        if let delegate = self as? MultiTappableDelegate { multiTapDelegate = delegate }
        let tap = UITapGestureRecognizer(target: self, action: #selector(UIView.multitapActionHandler))
        addGestureRecognizer(tap)
    }

    func multitapAction() {
        if tapCounter.value == 0 {
            DispatchQueue.global(qos: .utility).async {
                usleep(250_000)
                DispatchQueue.main.async { [weak self] in
                    guard let self = self else { return }
                    if self.tapCounter.value > 1 {
                        self.multiTapDelegate?.doubleTapDetected(in: self)
                    } else {
                        self.multiTapDelegate?.singleTapDetected(in: self)
                    }
                    self.tapCounter.value = 0
                }
            }
        }
        tapCounter.value += 1
    }
}

private extension UIView {
    @objc func multitapActionHandler() {
        if let tappable = self as? MultiTappable { tappable.multitapAction() }
    }
}

使用方法

class MyView: UIView, MultiTappable {
    weak var multiTapDelegate: MultiTappableDelegate?
    lazy var tapCounter = ThreadSafeValue(value: 0)
    override func awakeFromNib() {
        super.awakeFromNib()
        initMultiTap()
    }
}

完整示例

ViewController.swift

import UIKit

class ViewController: UIViewController {
    @IBOutlet weak var tableView: UITableView!
    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.dataSource = self
        tableView.tableFooterView = UIView()
    }
}

extension ViewController: UITableViewDataSource {

    func numberOfSections(in tableView: UITableView) -> Int { return 1 }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { return 10 }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "TableViewCell") as! TableViewCell
        cell.label.text = "\(indexPath)"
        cell.delegate = self
        return cell
    }
}

extension ViewController: TableViewCellDelegate {
    func singleTapDetected(in cell: TableViewCell)  {
        if let indexPath = tableView.indexPath(for: cell) { print("singleTap \(indexPath) ") }
    }
    func doubleTapDetected(in cell: TableViewCell) {
        if let indexPath = tableView.indexPath(for: cell) { print("doubleTap \(indexPath) ") }
    }
}

TableViewCell.swift

import UIKit

protocol TableViewCellDelegate: class {
    func singleTapDetected(in cell: TableViewCell)
    func doubleTapDetected(in cell: TableViewCell)
}

class TableViewCell: UITableViewCell, MultiTappable {
    weak var multiTapDelegate: MultiTappableDelegate?
    lazy var tapCounter = ThreadSafeValue(value: 0)

    @IBOutlet weak var label: UILabel!
    weak var delegate: TableViewCellDelegate?

    override func awakeFromNib() {
        super.awakeFromNib()
        initMultiTap()
    }
}

extension TableViewCell: MultiTappableDelegate {
    func singleTapDetected(in view: MultiTappable) { self.delegate?.singleTapDetected(in: self) }
    func doubleTapDetected(in view: MultiTappable) { self.delegate?.doubleTapDetected(in: self) }
}

Main.storyboard

<?xml version="1.0" encoding="UTF-8"?>
<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="12118" systemVersion="16E195" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" colorMatched="YES" initialViewController="g2V-T0-sqD">
    <device id="retina4_7" orientation="portrait">
        <adaptation id="fullscreen"/>
    </device>
    <dependencies>
        <deployment identifier="iOS"/>
        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="12086"/>
        <capability name="Constraints to layout margins" minToolsVersion="6.0"/>
        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
    </dependencies>
    <scenes>
        <!--View Controller-->
        <scene sceneID="tne-QT-ifu">
            <objects>
                <viewController id="BYZ-38-t0r" customClass="ViewController" customModule="stackoverflow_43153530" customModuleProvider="target" sceneMemberID="viewController">
                    <layoutGuides>
                        <viewControllerLayoutGuide type="top" id="y3c-jy-aDJ"/>
                        <viewControllerLayoutGuide type="bottom" id="wfy-db-euE"/>
                    </layoutGuides>
                    <view key="view" contentMode="scaleToFill" id="8bC-Xf-vdC">
                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                        <subviews>
                            <tableView clipsSubviews="YES" contentMode="scaleToFill" alwaysBounceVertical="YES" dataMode="prototypes" style="plain" separatorStyle="default" rowHeight="44" sectionHeaderHeight="28" sectionFooterHeight="28" translatesAutoresizingMaskIntoConstraints="NO" id="fQm-mQ-a9u">
                                <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
                                <color key="backgroundColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
                                <prototypes>
                                    <tableViewCell clipsSubviews="YES" contentMode="scaleToFill" selectionStyle="default" indentationWidth="10" reuseIdentifier="TableViewCell" id="nsF-ue-0bK" customClass="TableViewCell" customModule="stackoverflow_43153530" customModuleProvider="target">
                                        <rect key="frame" x="0.0" y="28" width="375" height="44"/>
                                        <autoresizingMask key="autoresizingMask"/>
                                        <tableViewCellContentView key="contentView" opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center" tableViewCell="nsF-ue-0bK" id="pT6-2N-oTC">
                                            <rect key="frame" x="0.0" y="0.0" width="375" height="44"/>
                                            <autoresizingMask key="autoresizingMask"/>
                                            <subviews>
                                                <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Label" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="fEK-J3-oqH">
                                                    <rect key="frame" x="8" y="8" width="42" height="21"/>
                                                    <fontDescription key="fontDescription" type="system" pointSize="17"/>
                                                    <nil key="textColor"/>
                                                    <nil key="highlightedColor"/>
                                                </label>
                                            </subviews>
                                            <constraints>
                                                <constraint firstItem="fEK-J3-oqH" firstAttribute="leading" secondItem="pT6-2N-oTC" secondAttribute="leadingMargin" id="Vfg-Ij-f6c"/>
                                                <constraint firstItem="fEK-J3-oqH" firstAttribute="top" secondItem="pT6-2N-oTC" secondAttribute="topMargin" id="tc0-qJ-N1n"/>
                                            </constraints>
                                        </tableViewCellContentView>
                                        <connections>
                                            <outlet property="label" destination="fEK-J3-oqH" id="YBJ-tG-J5T"/>
                                        </connections>
                                    </tableViewCell>
                                </prototypes>
                            </tableView>
                        </subviews>
                        <color key="backgroundColor" red="1" green="1" blue="1" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                        <constraints>
                            <constraint firstItem="fQm-mQ-a9u" firstAttribute="bottom" secondItem="wfy-db-euE" secondAttribute="top" id="8Vy-l8-jpB"/>
                            <constraint firstItem="fQm-mQ-a9u" firstAttribute="leading" secondItem="8bC-Xf-vdC" secondAttribute="leading" id="Wwr-ox-Qbd"/>
                            <constraint firstItem="fQm-mQ-a9u" firstAttribute="top" secondItem="y3c-jy-aDJ" secondAttribute="bottom" constant="-64" id="xJR-Uk-rbj"/>
                            <constraint firstAttribute="trailing" secondItem="fQm-mQ-a9u" secondAttribute="trailing" id="zxs-ED-Whb"/>
                        </constraints>
                    </view>
                    <navigationItem key="navigationItem" id="pLJ-Bz-NIm"/>
                    <connections>
                        <outlet property="tableView" destination="fQm-mQ-a9u" id="DhZ-jj-zmB"/>
                    </connections>
                </viewController>
                <placeholder placeholderIdentifier="IBFirstResponder" id="dkx-z0-nzr" sceneMemberID="firstResponder"/>
            </objects>
            <point key="canvasLocation" x="1079.2" y="137.18140929535232"/>
        </scene>
        <!--Navigation Controller-->
        <scene sceneID="w7e-Wj-oUR">
            <objects>
                <navigationController automaticallyAdjustsScrollViewInsets="NO" id="g2V-T0-sqD" sceneMemberID="viewController">
                    <toolbarItems/>
                    <navigationBar key="navigationBar" contentMode="scaleToFill" id="7qG-8v-S0O">
                        <rect key="frame" x="0.0" y="0.0" width="375" height="44"/>
                        <autoresizingMask key="autoresizingMask"/>
                    </navigationBar>
                    <nil name="viewControllers"/>
                    <connections>
                        <segue destination="BYZ-38-t0r" kind="relationship" relationship="rootViewController" id="yqZ-pK-Yf3"/>
                    </connections>
                </navigationController>
                <placeholder placeholderIdentifier="IBFirstResponder" id="tnz-x0-vDN" userLabel="First Responder" sceneMemberID="firstResponder"/>
            </objects>
            <point key="canvasLocation" x="140" y="137.18140929535232"/>
        </scene>
    </scenes>
</document>

结果

这里输入图片描述


这是一个图片链接，无法提供更多信息。
谢谢，它有效！尽管似乎有延迟更改某些UI。 - calvin sugianto
@Vasily Bodnarchuk，UICollectionView也可以以同样的方式工作吗？ - MD Sazid Hasan Dip
@MD.SazidHasanDip 是的，你可以使用相同的想法来处理UICollectionView。 - Vasily Bodnarchuk
2

对我而言，只需在UITableViewCell类中添加一个双击手势识别器即可。 像这样。

class TableViewCellSubclass: UITableViewCell {

    override func awakeFromNib() {
        super.awakeFromNib()
    
        let doubleTap = UITapGestureRecognizer(target: self, action: #selector(doubleTapFunc))
        doubleTap.numberOfTapsRequired = 2
        self.addGestureRecognizer(doubleTap)
    }

    @objc func doubleTapFunc() {
    }
}

对于单击操作，只需像平常一样使用didSelectRowAt方法。

我同意。它的工作非常干净利落。双击手势完全独立于单击手势，进入didSelectRowAt，因此不必担心一个会覆盖另一个并且弄乱了点击计数。使用您上面的示例，我添加了protocol TableViewCellSubclassDelegate { func doubleTapped(cell: TableViewCellSubclass) }然后是@objc func doubleTapFunc() { delegate?.doubleTapped(cell: self) }。实现此协议的视图控制器将能够捕获此双击并对其进行任何想要的操作。 - Kaplan
2
在单元格类中添加以下方法：
private func addSingleAndDoubleTapGesture() {
    let singleTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleSingleTap))
    singleTapGesture.numberOfTapsRequired = 1
    self.addGestureRecognizer(singleTapGesture)

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

    singleTapGesture.require(toFail: doubleTapGesture)
}

@objc private func handleSingleTap(_ tapGesture: UITapGestureRecognizer) {

}

@objc private func handleDoubleTap(_ tapGesture: UITapGestureRecognizer) {

}
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