ios - 如何在 Swift 中制作渐变圆形路径

我想创建一个如下图所示的渐变圆形路径:

我有以下代码:

    circularPath = UIBezierPath(arcCenter: .zero, radius: radius, startAngle: 0, endAngle: .pi * 2, clockwise: true)
    outerTrackShapeLayer = CAShapeLayer()
    outerTrackShapeLayer.path = circularPath.cgPath
    outerTrackShapeLayer.position = position
    outerTrackShapeLayer.strokeColor = outerTrackColor.cgColor
    outerTrackShapeLayer.fillColor = UIColor.clear.cgColor
    outerTrackShapeLayer.lineWidth = lineWidth
    outerTrackShapeLayer.strokeEnd = 1
    outerTrackShapeLayer.lineCap = CAShapeLayerLineCap.round
    outerTrackShapeLayer.transform = rotateTransformation
    addSublayer(outerTrackShapeLayer)

    innerTrackShapeLayer = CAShapeLayer()
    innerTrackShapeLayer.strokeColor = innerTrackColor.cgColor
    innerTrackShapeLayer.position = position
    innerTrackShapeLayer.strokeEnd = progress
    innerTrackShapeLayer.lineWidth = lineWidth
    innerTrackShapeLayer.lineCap = CAShapeLayerLineCap.round
    innerTrackShapeLayer.fillColor = UIColor.clear.cgColor
    innerTrackShapeLayer.path = circularPath.cgPath
    innerTrackShapeLayer.transform = rotateTransformation
    let gradient = CAGradientLayer()
    gradient.frame = circularPath.bounds
    gradient.colors = [UIColor.magenta.cgColor, UIColor.cyan.cgColor]
    gradient.position = innerTrackShapeLayer.position
    gradient.mask = innerTrackShapeLayer
    addSublayer(gradient)

但它不能正常工作，你可以在下图中看到结果:

如果有人帮助我，我将不胜感激，谢谢。

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Best Answer-推荐答案

看起来渐变层框架设置为等于路径框架，不包括 CAShapeLayer 的笔划厚度，这就是为什么它被截断为正方形。我无法从代码中看到 subview 上是否有圆形路径，但是如果将渐变框架设置为与应该对截断进行排序的 subview 框架相同，以及轨道上进度 View 的错位.

希望对您有所帮助。

关于ios - 如何在 Swift 中制作渐变圆形路径，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/54223709/