2017-08-16 150 views
0

有一个CAShapeLayerCAGradientLayer不画形式掩盖

enter image description here

,当我将它作为一个面具我得到一个空白屏幕

这里是我的代码:

let width: CGFloat = frame.width 
    let radius: CGFloat = (width - 35)/2 

    let poing = CGPoint(x: width/2, y: radius + 8) 
    let path = UIBezierPath(arcCenter: poing, radius: (width - 35)/2, 
         startAngle: CGFloat(180).toRadians(), 
         endAngle: CGFloat(360).toRadians(), 
         clockwise: true) 

    let mask = CAShapeLayer() 
    mask.path = path.cgPath 

    mask.lineWidth = 8 
    mask.strokeStart = 0 
    mask.strokeEnd = 1 
    mask.lineCap = kCALineCapRound 
    mask.fillColor = UIColor.clear.cgColor 
    mask.strokeColor = progressColor.cgColor 

    let gradient = CAGradientLayer() 
    gradient.frame = CGRect(x: 0, y: 0, width: frame.width, height: frame.height) 
    gradient.startPoint = CGPoint(x: 0, y: 1) 
    gradient.endPoint = CGPoint(x: 1, y: 1) 
    gradient.colors = [UIColor.white, UIColor.blue] 

    gradient.mask = mask 

    layer.addSublayer(gradient) 

我不明白为什么它不起作用。

回答

1

你简直忘了CALayer总是使用CGColor。

gradient.colors = [UIColor.white.cgColor, UIColor.blue.cgColor] 

希望它可以帮助