创建一个高度为1的虚线

 ///创建一个高为1的线-->实际使用

    func config() {

        let lineView = UIView(frame: CGRect(x: 10, y: 300, width: self.view.bounds.width - 20, height: 1))

        self.view.addSubview(lineView)

        drawDashLine(lineView: lineView, lineLength: 10, lineSpacing: 5, lineColor: UIColor.red)

    }

    

    /**

     *  通过 CAShapeLayer 方式绘制虚线

     *  lineView:       需要绘制成虚线的view

     *  lineLength:     线宽

     *  lineSpacing:    线间距

     **/

    func drawDashLine(lineView : UIView, lineLength : Int ,lineSpacing : Int,lineColor : UIColor){

        let shapeLayer = CAShapeLayer()

        shapeLayer.bounds = lineView.bounds

        //CALayer类型,anchorPoint默认(0.5,0.5)

        shapeLayer.anchorPoint = CGPoint(x: 0, y: 0)

        shapeLayer.fillColor = UIColor.clear.cgColor

        shapeLayer.strokeColor = lineColor.cgColor

        

        shapeLayer.lineWidth = lineView.frame.size.height

        shapeLayer.lineJoin = kCALineJoinRound

        

        shapeLayer.lineDashPattern = [NSNumber(value: lineLength), NSNumber(value: lineSpacing)]

        

        let path = CGMutablePath()

        path.move(to: CGPoint(x: 0, y: 0))

        path.addLine(to: CGPoint(x: lineView.frame.size.width, y: 0))

        

        shapeLayer.path = path

        lineView.layer.addSublayer(shapeLayer)

    }