UILabel指定角设置圆角

let corner = UIRectCorner(rawValue: UIRectCorner.topLeft.rawValue | UIRectCorner.topRight.rawValue)
let maskPath = UIBezierPath(roundedRect: self.bounds, byRoundingCorners: corner, cornerRadii: CGSize(width: 10, height: 10))
let maskLayer = CAShapeLayer()
maskLayer.frame = self.bounds
maskLayer.path = maskPath.cgPath
myLabel.layer.mask = maskLayer