Objectivec 仅在 UIView 顶部的圆角

发布于04月25日

嗨，我正在寻找一个干净的解决方案，不覆盖drawRect或类似的东西，以创建一个UIView与圆角上的View.我这里的主要问题是，如果视图正在调整大小或类似的事情，则创建变量解决方案.

推荐答案

可以通过在视图的图层上设置mask来实现:

CAShapeLayer * maskLayer = [CAShapeLayer layer];
maskLayer.path = [UIBezierPath bezierPathWithRoundedRect: self.bounds byRoundingCorners: UIRectCornerTopLeft | UIRectCornerTopRight cornerRadii: (CGSize){10.0, 10.}].CGPath;

self.layer.mask = maskLayer;

IMPORTANT:您应该在视图的layoutSubviews()方法中执行此操作，因此视图已经从情节提要中调整了大小

In Swift <= 1.2

let maskLayer = CAShapeLayer()
maskLayer.path = UIBezierPath(roundedRect: bounds, byRoundingCorners: .TopLeft | .TopRight, cornerRadii: CGSize(width: 10.0, height: 10.0)).CGPath

layer.mask = maskLayer

Swift 2.x

let maskLayer = CAShapeLayer()
maskLayer.path = UIBezierPath(roundedRect: bounds, byRoundingCorners: UIRectCorner.TopLeft.union(.TopRight), cornerRadii: CGSizeMake(10, 10)).CGPath
layer.mask = maskLayer

Swift 3.x

let maskLayer = CAShapeLayer()
maskLayer.path = UIBezierPath(roundedRect: view.bounds, byRoundingCorners: [.topLeft, .topRight], cornerRadii: CGSize(width: 10, height: 10)).cgPath
layer.mask = maskLayer