小编Sha*_*Ali的帖子

我正在尝试用虚线做一个圆圈。我能够在矩形中制作线条，但我不知道如何在圆形中制作这些线条。这是我得到的答案，但它在 Objective-C 中：UIView Draw Circle with Dotted Line Border

这是我的代码，它用虚线制作了一个矩形。

func addDashedBorder() {
    let color = UIColor.red.cgColor

    let shapeLayer:CAShapeLayer = CAShapeLayer()
    let frameSize = self.frame.size
    let shapeRect = CGRect(x: 0, y: 0, width: frameSize.width, height: frameSize.height)

    shapeLayer.bounds = shapeRect
    shapeLayer.position = CGPoint(x: frameSize.width/2, y: frameSize.height/2)
    shapeLayer.fillColor = UIColor.clear.cgColor
    shapeLayer.strokeColor = color
    shapeLayer.lineWidth = 2
    shapeLayer.lineJoin = CAShapeLayerLineJoin.round
    shapeLayer.lineDashPattern = [6,3]
    shapeLayer.path = UIBezierPath(roundedRect: shapeRect, cornerRadius: 5).cgPath

    self.layer.addSublayer(shapeLayer)
}