如何防止在两次点击函数中调用一次点击函数？

Question

我正在尝试向我的按钮添加自定义行为。如果单击一次 - 执行一项操作。如果单击两次，则会执行另一次。

我看到such a solution in this answer 并且尝试了所有可能的组合：

        clickOnce.shouldBeRequiredToFailByGestureRecognizer(clickTwice)
        clickTwice.shouldBeRequiredToFailByGestureRecognizer(clickOnce)
        clickOnce.shouldRequireFailureOfGestureRecognizer(clickTwice)
        clickTwice.shouldRequireFailureOfGestureRecognizer(clickOnce)
        clickOnce.canPreventGestureRecognizer(clickTwice)
        clickOnce.canBePreventedByGestureRecognizer(clickTwice)
        clickTwice.canPreventGestureRecognizer(clickOnce)
        clickTwice.canBePreventedByGestureRecognizer(clickOnce)

但对我没有任何帮助。

这是完整的代码：

import Cocoa

class ViewController: NSViewController {
    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.

        let buttonTestOne = NSButton(frame: CGRect(x: 500, y: 500, width: 100, height: 500))

        let clickOnceForTestOne = NSClickGestureRecognizer(target: buttonTestOne, action: #selector(ViewController.clickOneTime(_:)))
        clickOnceForTestOne.numberOfClicksRequired = 1
        buttonTestOne.addGestureRecognizer(clickOnceForTestOne)
        self.view.addSubview(buttonTestOne)

        let arrTestButtons = ["One", "Two", "Three"]

        var x = 0
        var y = 0

        for item in arrTestButtons{
            let buttonNew = NSButton(frame: CGRect(x: x, y: y, width: 100, height: 100))
            x = x + 120
            y = y + 120
            buttonNew.attributedTitle = NSAttributedString(string: item)
            let clickOnce = NSClickGestureRecognizer(target: self, action: #selector(ViewController.clickOneTime(_:)))
            clickOnce.numberOfClicksRequired = 1
            buttonNew.addGestureRecognizer(clickOnce)
            let clickTwice = NSClickGestureRecognizer(target: self, action: #selector(ViewController.clickTwoTimes(_:)))
            clickTwice.numberOfClicksRequired = 2
            buttonNew.addGestureRecognizer(clickTwice)
            clickOnce.shouldBeRequiredToFailByGestureRecognizer(clickTwice)
            clickTwice.shouldBeRequiredToFailByGestureRecognizer(clickOnce)
            clickOnce.shouldRequireFailureOfGestureRecognizer(clickTwice)
            clickTwice.shouldRequireFailureOfGestureRecognizer(clickOnce)
            clickOnce.canPreventGestureRecognizer(clickTwice)
            clickOnce.canBePreventedByGestureRecognizer(clickTwice)
            clickTwice.canPreventGestureRecognizer(clickOnce)
            clickTwice.canBePreventedByGestureRecognizer(clickOnce)

            self.view.addSubview(buttonNew)
        }


    }

    func clickOneTime(g:NSClickGestureRecognizer){
        if g.state == .Ended {
            Swift.print("single click")
        }
    }
    func clickTwoTimes(g: NSClickGestureRecognizer){
        if g.state == .Ended {
            Swift.print("DOUBLE CLICK!")
        }
    }
    override var representedObject: AnyObject? {
        didSet {
        // Update the view, if already loaded.
        }
    }


}

我做错了什么？我想这个错误一定很简单，我要么打错地方了，要么有点类似，但我看不懂。

这是日志文件，所有组合都相同：

点击一次：

single click

如预期的那样

点击了两次：

single click
DOUBLE CLICK!

同时启动单击和双击。

我已阅读文档。而且我已经尝试了所有组合，因为找不到解决方案。

我也尝试过使用日志。所以Swift.print(clickOnce.shouldBeRequiredToFailByGestureRecognizer(clickTwice)) 和其中之一，但它给了我false。

Answer 1

我试图自己解决这个问题；事实证明，解决方案相对简单。

使用手势识别器进行双击（这里，我已将它们添加到视图中，但同样的原理应该适用于按钮）

let doubleClickRecognizer = NSClickGestureRecognizer(target: self, action: #selector(ViewController.clickTwice))
doubleClickRecognizer.numberOfClicksRequired = 2
self.view?.addGestureRecognizer(doubleClickRecognizer)

添加

@objc func clickTwice() {
    print("double click")
}

然后通过处理单击

override func mouseDown(with event: NSEvent) {
    print("mouse down; once")
}

（或适当的等效项）。

NSGestureRecognizer 有

var delaysPrimaryMouseButtonEvents: Bool

默认情况下设置为 true，因此使用这种组合，它会等到 doubleClickRecognizer 处理完双击，然后再向上响应者链查看还有谁对鼠标点击感兴趣。

两个手势识别器与处理 mouseDown 中的单击和双击具有相同的问题：单击首先触发。为了克服这个问题，您需要覆盖

func gestureRecognizer(_ gestureRecognizer: NSGestureRecognizer, shouldRequireFailureOf otherGestureRecognizer: NSGestureRecognizer) -> Bool  

这不是您调用的函数，而是您覆盖的委托函数。因此，您将 viewController 设置为符合 NSGestureRecognizerDelegate （这意味着它将接收委托方法）；设置 singleClickRecognizer.delegate = self（其中 self 是您的 viewController），并实现

func gestureRecognizer(_ gestureRecognizer: NSGestureRecognizer, shouldRequireFailureOf otherGestureRecognizer: NSGestureRecognizer) -> Bool {
    if gestureRecognizer == singleClickRecognizer && otherGestureRecognizer == doubleClickRecognizer {
        return true
    }
    return false
    }

这表明您的 singleClickRecognizer 在执行其选择器之前等待 doubleClickRecognizer 失败。

不幸的是，我发现在 SpriteKit 中，虽然这段代码执行了它在锡上所说的那样（首先处理双击），但它会导致无法接受的延迟，所以我不确定我是否可以推荐它。

Answer 2

试试这个：

let click = NSClickGestureRecognizer(target: self, action: #selector(clicked(_:))
click.numberOfClicksRequired = 2

Answer 3

也许你可以这样尝试，“按钮”是你的按钮

let doubleTapRecognizer = UITapGestureRecognizer(target: self, action: #selector(ViewController.clickTwoTimes(_:)))
let singleTapRecognizer = UITapGestureRecognizer(target: self, action: #selector(ViewController.clickOneTime(_:)))
singleTapRecognizer.numberOfTapsRequired = 1
doubleTapRecognizer.numberOfTapsRequired = 2
button.addGestureRecognizer(doubleTapRecognizer)
button.addGestureRecognizer(singleTapRecognizer)
singleTapRecognizer.requireGestureRecognizerToFail(doubleTapRecognizer)