swift – 带圆角的虚线

参见英文答案 > CoreGraphics line appears to change size?2个
我试图在这样的视图周围绘制带圆角的虚线：

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()
    }
}

@H_502_4@结果是：

@H_502_4@

@H_502_4@你可以看到角落有问题,任何想法如何修复它？

@H_502_4@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
    }
}

我在使用CAShapeLayer方面有很好的经验.例如：

let rect = CGRect.init(origin: CGPoint.init(x: 20,y: 100),size: CGSize.init(width: 200,height: 100))
let layer = CAShapeLayer.init()
let path = UIBezierPath(roundedRect: rect,cornerRadius: 8)
layer.path = path.cgPath;
layer.strokeColor = UIColor.red.cgColor;
layer.lineDashPattern = [3,3];
layer.backgroundColor = UIColor.clear.cgColor;
layer.fillColor = UIColor.clear.cgColor;
self.view.layer.addSublayer(layer);

@H_502_4@作为奖励,几乎所有CAShapeLayer的属性都是可动画的,包括lineDashPhase,这意味着你可以让它看起来像破折号在盒子周围移动.