淹没的虚线在斯威夫特变得奇怪

Question

我正在尝试在UIView中绘制一些虚线，但我不知道我做得是否正确。与其他破折号相比，第一个破折号的宽度为一半。

法典：

    let strokeColor                      = UIColor.white.cgColor
    let path = UIBezierPath()
    path2.move(to: CGPoint(x: 0, y: 50)) 
    path2.addLine(to: CGPoint(x: 340, y: 50))
    //thickHorizontalLayer.frame         = frame
    thickHorizontalLayer.path            = path.cgPath
    thickHorizontalLayer.strokeColor     = strokeColor
    thickHorizontalLayer.lineWidth       = 15
    thickHorizontalLayer.fillColor       = UIColor.clear.cgColor
    thickHorizontalLayer.lineDashPattern = [ 0.5, 6 ]
    thickHorizontalLayer.lineDashPhase   = 0.25
    self.layer.addSublayer(thickHorizontalLayer)

看看它画了什么：https://i.stack.imgur.com/7UTdj.jpg

这是最好的方法吗？如果你看到，第一个破折号比其他破折号更薄......

加上问题：我如何获得 UIView 绑定的 y 值？例如 bound=340，这是上面的情况。

编辑：

我正在尝试绘制 2 个破折号图案(一个薄，另一个厚(，但它变得令人困惑......

    fileprivate let thickHorizontalLayer = CAShapeLayer()
    fileprivate let thinHorizontalLayer = CAShapeLayer()
    let strokeColor                      = UIColor.white.cgColor
    let path2 = UIBezierPath()
    path2.move(to: CGPoint(x: 20, y: 50)) 
    path2.addLine(to: CGPoint(x: 320, y: 50)) 
    //thickHorizontalLayer.frame           = frame
    thickHorizontalLayer.path            = path2.cgPath
    thickHorizontalLayer.strokeColor     = strokeColor
    thickHorizontalLayer.lineWidth       = 20
    thickHorizontalLayer.fillColor       = UIColor.clear.cgColor
    thickHorizontalLayer.lineDashPattern = [ 1, 73.5 ]
    //thickHorizontalLayer.lineDashPhase   = 0.25
    self.layer.addSublayer(thickHorizontalLayer)
    let path3 = UIBezierPath()
    path3.move(to: CGPoint(x: 0, y: 52.5)) 
    path3.addLine(to: CGPoint(x: 340.0, y: 52.5)) 

    //thinHorizontalLayer.frame            = frame
    thinHorizontalLayer.path             = path3.cgPath
    thinHorizontalLayer.strokeColor      = strokeColor
    thinHorizontalLayer.lineWidth        = 15.0
    thinHorizontalLayer.fillColor        = UIColor.clear.cgColor
    thinHorizontalLayer.lineDashPattern  = [ 0.5, 6.25 ]
    //thinHorizontalLayer.lineDashPhase    = 0.25
    self.layer.addSublayer(thinHorizontalLayer)

它的图是这样的：https://i.stack.imgur.com/x0AbL.jpg

如果仔细观察，可以看到它变得越来越奇怪(见破折号的颜色(... ： https://i.stack.imgur.com/1dF0Q.jpg

我正在尝试从 x：20 到 x：320 以及它们之间绘制 5 个破折号(但在 x：0 处声明到 x：340( 绘制 9 个较细的破折号。希望有人能帮我解决这个问题...

Answer 1

我已经解决了这个问题：如何在 Swift 上使用 UIbezierPath 进行通用回合绘制(使用 lineDashPattern(

    public override func draw(_ rect: CGRect) {
        let center = CGPoint(x:bounds.width/2, y: bounds.height)
        var radius: CGFloat = max(bounds.width, bounds.height+50)
        // Define the thickness of the arc.
        let arcWidth: CGFloat = 1
        let startAngle: CGFloat = CGFloat(M_PI) // π
        let endAngle: CGFloat = CGFloat(2 * M_PI) // π
        let counterColor = UIColor.red
        var path = UIBezierPath(arcCenter: center,
                                radius: radius/2 - arcWidth/2,
                                startAngle: startAngle,
                                endAngle: endAngle,
                                clockwise: true)
        path.lineWidth = arcWidth
        counterColor.setStroke()
        path.stroke()

        // init vars for later use
        var nTicks = 0
        var tickWidth = 0.0
        var gapWidth = 0.0

        radius += 20
        path = UIBezierPath(arcCenter: center,
                            radius: radius/2 - arcWidth/2,
                            startAngle: startAngle,
                            endAngle: endAngle,
                            clockwise: true)
        let strokeColor            = UIColor.black.cgColor
        let roundThinLayer = CAShapeLayer()
        // number of short ticks to draw
        nTicks = 150
        // thickness of short ticks
        tickWidth = 0.5
        // calculate the gap between ticks
        gapWidth = ((M_PI * Double(radius) / 2) - (tickWidth * Double(nTicks))) / Double(nTicks - 1)
        roundThinLayer.path             = path.cgPath
        roundThinLayer.strokeColor      = strokeColor
        roundThinLayer.lineWidth        = 20.0
        roundThinLayer.fillColor        = UIColor.clear.cgColor
        roundThinLayer.lineDashPattern  = [ tickWidth as NSNumber, gapWidth as NSNumber ]
        roundThinLayer.lineDashPhase    = CGFloat(tickWidth / Double(2))

        self.layer.addSublayer(roundThinLayer)

        radius += 20
        path = UIBezierPath(arcCenter: center,
                            radius: radius/2 - arcWidth/2,
                            startAngle: startAngle,
                            endAngle: endAngle,
                            clockwise: true)
        let roundThickLayer = CAShapeLayer()

        // number of tall ticks to draw
        nTicks = 7
        // thickness of tall ticks
        tickWidth = 1.5
        // calculate the gap between ticks
        gapWidth = ((M_PI * Double(radius) / 2) - (tickWidth * Double(nTicks))) / Double(nTicks - 1)
        roundThickLayer.path            = path.cgPath
        roundThickLayer.strokeColor     = strokeColor
        roundThickLayer.lineWidth       = 40
        roundThickLayer.fillColor       = UIColor.clear.cgColor
        roundThickLayer.lineDashPattern = [ tickWidth as NSNumber, gapWidth as NSNumber ]
        roundThickLayer.lineDashPhase   = CGFloat(tickWidth / Double(2))
        self.layer.addSublayer(roundThickLayer)
        self.clipsToBounds = true

    }