title: Border only in corners with UIBezierPath() wrong space in lineDashPattern
body: <p>Im trying to create a view with border only in corners (qrCode style) using lineDashPattern, but the space between the lines doesn't seem to match with the Pattern defined by me. This is my playground:</p>
  <pre><code>override func loadView() {
      let view = UIView()
      view.backgroundColor = .white
      let myView = UIView(frame: CGRect(x: 50, y: 50, width: 200, height: 200))
      myView.backgroundColor = .black
      let borderLayer = CAShapeLayer()
      let d = (myView.bounds.width / 2) as NSNumber
      borderLayer.strokeColor = UIColor.blue.cgColor
      borderLayer.lineDashPattern = [d]
      borderLayer.frame = myView.bounds
      borderLayer.fillColor = nil
      borderLayer.lineWidth = 10
      borderLayer.strokeStart = 0.1
      //borderLayer.lineDashPhase = -80
      borderLayer.path = UIBezierPath(roundedRect: myView.bounds, byRoundingCorners: .allCorners, cornerRadii: CGSize(width: 30, height: 30)).cgPath
      borderLayer.lineCap = CAShapeLayerLineCap.round
      myView.layer.addSublayer(borderLayer)
      view.addSubview(myView)
      self.view = view
  }
  </code></pre>
  <p><a href="https://i.stack.imgur.com/PYg1N.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/PYg1N.png" alt="enter image description here" /></a></p>
  <p>I'm trying to adjust the start of the lines with the lineDashPhase and strokeStart attributes, but doesn't seems to work. Can someone help me?</p>