swift 自定义圆角

// 直接调用

    let maskPath = UIBezierPath.init(roundedRect: self.giveLable.bounds, byRoundingCorners: UIRectCorner(rawValue: UIRectCorner.topLeft.rawValue | UIRectCorner.bottomRight.rawValue | UIRectCorner.topRight.rawValue), cornerRadii: CGSize(width: 40, height:15)) 
    let maskLayer = CAShapeLayer()
    maskLayer.frame = self.giveLable.bounds
    maskLayer.path = maskPath.cgPath
    self.giveLable.layer.mask = maskLayer

//view扩展

   extension UIView {

/// 部分圆角
///
/// - Parameters:
///   - corners: 需要实现为圆角的角，可传入多个
///   - radii: 圆角半径
func extCorner(corners: UIRectCorner, radii: CGFloat) {
    let maskPath = UIBezierPath.init(roundedRect: self.bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radii, height: radii))
    let maskLayer = CAShapeLayer()
    maskLayer.frame = self.bounds
    maskLayer.path = maskPath.cgPath
    self.layer.mask = maskLayer
}
}