在UITextField底部绘制虚线

我试图在UITextField底部画一条虚线，但没有成功。 以下是我到目前为止所尝试的。 请指导。

func addDashedBorder() { let color = UIColor.white.cgColor let width = CGFloat(2.0) let shapeLayer:CAShapeLayer = CAShapeLayer() let frameSize = self.frame.size let shapeRect = CGRect(x: 0, y: frameSize.height, width: frameSize.width, height: 2.0) shapeLayer.bounds = shapeRect shapeLayer.position = CGPoint(x: frameSize.width/2, y: frameSize.height - width) shapeLayer.fillColor = UIColor.darkGray.cgColor shapeLayer.strokeColor = color shapeLayer.lineWidth = 2.0 // shapeLayer.lineJoin = kCALineJoinRound shapeLayer.lineDashPattern = [6,3] shapeLayer.path = UIBezierPath(rect: shapeRect).cgPath//UIBezierPath(roundedRect: shapeRect, cornerRadius: 0).cgPath self.layer.addSublayer(shapeLayer) } } 

输出得到的是：

预计是：

Answer 1

终于修好了：

 extension UIView { func addDashedLine(strokeColor: UIColor, lineWidth: CGFloat) { backgroundColor = .clear let shapeLayer = CAShapeLayer() shapeLayer.name = "DashedTopLine" shapeLayer.bounds = bounds shapeLayer.position = CGPoint(x: frame.width / 2, y: frame.height * 1.2) shapeLayer.fillColor = UIColor.clear.cgColor shapeLayer.strokeColor = strokeColor.cgColor shapeLayer.lineWidth = lineWidth shapeLayer.lineJoin = kCALineJoinRound shapeLayer.lineDashPattern = [6, 4] let path = CGMutablePath() path.move(to: CGPoint.zero) path.addLine(to: CGPoint(x: frame.width, y: 0)) shapeLayer.path = path layer.addSublayer(shapeLayer) } 

}

从这里得到了帮助：[用CALayer绘制虚线

] 1

Answer 2

尝试这个

使用点图像：

 self.textField.layer.borderWidth = 3 self.textField.layer.borderColor = (UIColor(patternImage: UIImage(named: "dot")!)).CGColor 

更新：

下面使用扩展名

 mytextfield.addDashedLine(strokeColor:.red,lineWidth:1) extension UIView { func addDashedLine(strokeColor: UIColor, lineWidth: CGFloat) { backgroundColor = .clear let shapeLayer = CAShapeLayer() shapeLayer.name = "DashedTopLine" shapeLayer.bounds = bounds shapeLayer.position = CGPoint(x:30, y: 40) shapeLayer.fillColor = UIColor.clear.cgColor shapeLayer.strokeColor = strokeColor.cgColor shapeLayer.lineWidth = lineWidth shapeLayer.lineJoin = kCALineJoinRound shapeLayer.lineDashPattern = [4, 4] let path = CGMutablePath() path.move(to: CGPoint.zero) path.addLine(to: CGPoint(x:500, y: 0)) shapeLayer.path = path layer.addSublayer(shapeLayer) } }