ios - 如何屏蔽和添加阴影到 UIView

Question

我正在制作一个自定义 View ，我想屏蔽它并为其添加阴影。

掩码:

    let p = UIBezierPath()
    p.moveToPoint(CGPointMake(20, 20))
    p.addLineToPoint(CGPointMake(100, 20))
    p.addLineToPoint(CGPointMake(100, 50))
    p.addLineToPoint(CGPointMake(110, 55))
    p.addLineToPoint(CGPointMake(100, 60))
    p.addLineToPoint(CGPointMake(100, 100))
    p.addLineToPoint(CGPointMake(20, 100))
    p.closePath()

    let s = CAShapeLayer()
    s.frame = layer.bounds
    s.path = p.CGPath
    s.fillColor = UIColor.greenColor().CGColor
    layer.mask = s

蒙版有效，现在我想添加阴影。但它不起作用。

我尝试向主层添加阴影，但没有任何反应。

    layer.shadowColor = UIColor.yellowColor().CGColor
    layer.shadowRadius = 10
    layer.shadowOpacity = 0.9
    layer.shadowOffset = CGSizeZero

我尝试将它添加到 mask 层，但主视图被阴影遮住了。

    s.shadowColor = UIColor.yellowColor().CGColor
    s.shadowRadius = 10
    s.shadowOpacity = 0.9
    s.shadowOffset = CGSizeZero

有什么关于如何将这个黄色阴影添加到蒙版 View 的建议吗？

谢谢

Answer 1

感谢@WilsonXJ我将蒙版更改为 addSubLayer。

这是对我有用的答案:

    let p = UIBezierPath()
    p.moveToPoint(CGPointMake(20, 20))
    p.addLineToPoint(CGPointMake(100, 20))
    p.addLineToPoint(CGPointMake(100, 50))
    p.addLineToPoint(CGPointMake(110, 55))
    p.addLineToPoint(CGPointMake(100, 60))
    p.addLineToPoint(CGPointMake(100, 100))
    p.addLineToPoint(CGPointMake(20, 100))
    p.closePath()

    let s = CAShapeLayer()
    s.fillColor = UIColor.whiteColor().CGColor
    s.frame = layer.bounds
    s.path = p.CGPath

    layer.backgroundColor = UIColor.clearColor().CGColor
    layer.addSublayer(s)

    layer.masksToBounds = true
    layer.shadowColor = UIColor.yellowColor().CGColor
    layer.shadowOffset = CGSizeZero
    layer.shadowOpacity = 0.9
    layer.shadowPath = p.CGPath
    layer.shadowRadius = 10