飘忽不定的动作iOS swift UITouch

Question

simulator gif
physical device gif

在我的 swift 应用程序中，我制作了一个自定义图表来显示股票价格的历史。单指触摸将显示特定的股票价格和日期。两指触摸将显示价格的平均值。

我的问题是，每当我在模拟器中执行我的应用程序时，它在使用两个手指（选项+鼠标）时运行良好。但是在物理设备（iPhone 5s）上执行并使用 2 个手指时，这两个条似乎不规律地移动并开始闪烁。

 override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {

    handleTouch(touches: touches)
}

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {

    if delegate != nil{
        delegate!.chartStopped()
    }

}

private func handleTouch(touches:Set<UITouch>){
    if touches.count == 1{
        if let loc = touches.first?.location(in: self){
            let xRawValue = getClosest(searchValue: Int(loc.x), arrayValue: self.xRaw)
            let yRawValue = self.yRaw[self.xRaw.index(of: xRawValue)!]
            self.date = self.x[self.xRaw.index(of: xRawValue)!]
            self.price = self.y[self.xRaw.index(of: xRawValue)!]
            drawLines(xRawValue: xRawValue, yRawValue: yRawValue,lineLayer: lineLayer,circleLayer: circleLayer)
            //self.lineLayerS.path = UIBezierPath().cgPath
            //self.circleLayerS.path = UIBezierPath().cgPath
            if delegate != nil{
                delegate!.chartMoved(currentPrice: self.price, currentDate: self.date)
            }
        }
    } else if touches.count == 2{
        var touch = touches
        let touchF = touch.popFirst()
        if var loc1 = touchF?.location(in: self), var loc2 = touch.first?.location(in: self){
            if loc1.x > loc2.x{
                swap(&loc1, &loc2)
            }


            let xRawValue1 = getClosest(searchValue: Int(loc1.x), arrayValue: self.xRaw)
            let xIndex1 = self.xRaw.index(of: xRawValue1)!

            let yRawValue1 = self.yRaw[xIndex1]

            let xRawValue2 = getClosest(searchValue: Int(loc2.x), arrayValue: self.xRaw)
            let xIndex2 = self.xRaw.index(of: xRawValue2)!

            let yRawValue2 = self.yRaw[xIndex2]



            var averageSum = 0.0
            for i in xIndex1..<xIndex2{
                averageSum += Double(self.y[i])
            }
            averageSum = averageSum/Double(xIndex2-xIndex1)
            self.date = self.x[xIndex1]+"-"+self.x[xIndex2]
            self.price = Float(averageSum)
            if delegate != nil{
                delegate!.chartMoved(currentPrice: self.price, currentDate: self.date)
            }
            drawLines(xRawValue: xRawValue1, yRawValue: yRawValue1,lineLayer: lineLayer,circleLayer: circleLayer)
            drawLines(xRawValue: xRawValue2, yRawValue: yRawValue2,lineLayer: lineLayerS,circleLayer: circleLayerS)
        }
    }
}


private func drawLines(xRawValue xV:Int,yRawValue yV:Int,lineLayer:CAShapeLayer,circleLayer:CAShapeLayer){
    let line = UIBezierPath(rect: CGRect(x: xV, y:0, width: 1, height: Int(self.frame.height)))
    lineLayer.path = line.cgPath
    lineLayer.strokeColor = UIColor.black.cgColor
    circleLayer.path = UIBezierPath(ovalIn: CGRect(x: xV-4, y: yV-4, width: 8, height: 8)).cgPath;
    circleLayer.strokeColor = Colors.blueDark.cgColor
    circleLayer.fillColor = Colors.blueDark.cgColor
    self.layer.addSublayer(circleLayer)
}

https://www.youtube.com/watch?v=7RiWXxYh9pk&feature=youtu.behttps://www.youtube.com/watch?v=NfSb09NKxH4&feature=youtu.be

Answer 1

这是解决问题的一种方法。

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    for touch in touches {
        let touch = touch.location(in: self)

        //height --> height of your chart
        let touchArea = SKSpriteNode(color: .clear, size: CGSize(width: 20, height: 200))
        touchArea.position = touch
    }
}

您可以创建一个可以识别第一次触摸的范围，这样就不会再出现问题了。问题在于，当您的设备识别出您的手指触摸时，设备无法准确定位该触摸，因为您同时触摸了多个像素。

Apple 解决了这个问题，它允许线条的位置仅位于图表的边缘，正如您在股票应用中看到的那样。

让我知道它是否有效。