Swift 渐变色圆角边框

extension UIView {
    
    func addGradientLayerWith(cornerRadius:CGFloat, lineWidth:CGFloat, colors: [CGColor]) {
        let gradientLayer = CAGradientLayer()
        gradientLayer.frame = self.bounds
        gradientLayer.colors = colors
        gradientLayer.cornerRadius = cornerRadius
        
        let maskLayer = CAShapeLayer()
        maskLayer.lineWidth = lineWidth
        maskLayer.path = UIBezierPath(roundedRect: CGRect(x: lineWidth / 2, y: lineWidth / 2, width: bounds.width - lineWidth, height: bounds.height - lineWidth), cornerRadius: cornerRadius).cgPath
        maskLayer.fillColor = UIColor.clear.cgColor
        maskLayer.strokeColor = UIColor.black.cgColor
        
        gradientLayer.mask = maskLayer
        self.layer.addSublayer(gradientLayer)
    }
}