Swift绘制虚线

extension UIView{
    //MARK:- 绘制虚线
    func drawDashLine(_ lineView:UIView,strokeColor: UIColor, lineWidth: CGFloat = 1, lineLength: Int = 10, lineSpacing: Int = 5) {
        let shapeLayer = CAShapeLayer()
        shapeLayer.bounds = lineView.bounds
        shapeLayer.anchorPoint = CGPoint(x: 0, y: 0)
        shapeLayer.fillColor = UIColor.blue.cgColor
        shapeLayer.strokeColor = strokeColor.cgColor
        
        shapeLayer.lineWidth = lineWidth
        shapeLayer.lineJoin = CAShapeLayerLineJoin.round
        
        //每一段虚线长度 和 每两段虚线之间的间隔
        shapeLayer.lineDashPattern = [NSNumber(value: lineLength), NSNumber(value: lineSpacing)]
        
        let path = CGMutablePath()
//        let y = lineView.layer.bounds.height - lineWidth
        let x = lineView.layer.bounds.width - lineWidth
        path.move(to: CGPoint(x: x, y: 0))
        path.addLine(to: CGPoint(x: x, y: lineView.layer.bounds.height))
        shapeLayer.path = path
        lineView.layer.addSublayer(shapeLayer)
    }
}