swift – 带圆角的虚线

class DashedLineView: UIView {

    override func draw(_ rect: CGRect) {

        let path = UIBezierPath(roundedRect: rect,cornerRadius: 8)

        UIColor.clear.setFill()
        path.fill()

        UIColor.red.setstroke()
        path.lineWidth = 3

        let dashPattern : [CGFloat] = [3,3]
        path.setLineDash(dashPattern,count: 2,phase: 0)
        path.stroke()
    }
}

结果是：

你可以看到角落有问题,任何想法如何修复它？

更新：
使用@Jon Rose answer DashedLineView现在看起来像这样：

class DashedLineView: UIView {

    private let borderLayer = CAShapeLayer()

    override func awakeFromNib() {

        super.awakeFromNib()

        borderLayer.strokeColor = UIColor.red.cgColor
        borderLayer.lineDashPattern = [3,3]
        borderLayer.BACkgroundColor = UIColor.clear.cgColor
        borderLayer.fillColor = UIColor.clear.cgColor

        layer.addSublayer(borderLayer)
    }

    override func draw(_ rect: CGRect) {

        borderLayer.path = UIBezierPath(roundedRect: rect,cornerRadius: 8).cgPath
    }
}