用Swift如何编程实现渐变边框UIButton?

Question

我该如何以编程方式设计类似于这个渐变边框颜色的UIButton？

感谢您的帮助。

- m.akyol

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请查看此链接：https://dev59.com/yF0b5IYBdhLWcg3wA9LI - kb920

我需要渐变边框颜色，请点击链接：) - m.akyol

请点击以下链接：https://dev59.com/WWUp5IYBdhLWcg3wj4Lu https://dev59.com/d2LVa4cB1Zd3GeqPz9Bd - Sheereen S

Answer 1

let gradient = CAGradientLayer()
gradient.frame =  CGRect(origin: CGPointZero, size: self.myButton.frame.size)
gradient.colors = [UIColor.blueColor().CGColor, UIColor.greenColor().CGColor]

let shape = CAShapeLayer()
shape.lineWidth = 2
shape.path = UIBezierPath(rect: self.myButton.bounds).CGPath
shape.strokeColor = UIColor.blackColor().CGColor
shape.fillColor = UIColor.clearColor().CGColor
gradient.mask = shape

self.myButton.layer.addSublayer(gradient)

Swift 3版本：

    let gradient = CAGradientLayer()
    gradient.frame =  CGRect(origin: CGPoint.zero, size: self.myButton.frame.size)
    gradient.colors = [UIColor.blue.cgColor, UIColor.green.cgColor]

    let shape = CAShapeLayer()
    shape.lineWidth = 2
    shape.path = UIBezierPath(rect: self.myButton.bounds).cgPath
    shape.strokeColor = UIColor.black.cgColor
    shape.fillColor = UIColor.clear.cgColor
    gradient.mask = shape

    self.myButton.layer.addSublayer(gradient)

- gvuksic

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可以正常运作，但是是否可能将角落变为圆角而不是尖角呢？ - Ahmad

@Ahmad，你可以使用cornerRadius属性。 - Hellojeffy

为按钮添加圆角： shape.path = UIBezierPath(roundedRect: self.myButton.bounds, cornerRadius: self.myButton.cornerRadius).cgPath。 - Sameh

不要忘记添加 self.myButton.clipsToBounds = true 以正确显示圆角半径。 - Ivan Smetanin

要在Swift 4.2+中添加圆角，请使用以下代码：myButton.layer.cornerRadius = 25 shape.path = UIBezierPath(roundedRect: myButton.bounds, cornerRadius: myButton.layer.cornerRadius).cgPath cornerRadius是层的属性，而不是UIButton的属性。 - Pankaj Kulkarni