//        let beizer:UIBezierPath = UIBezierPath(roundedRect: btn5.bounds, byRoundingCorners: UIRectCorner.TopLeft|UIRectCorner.TopRight, cornerRadii: CGSize(width: 15, height: 15))

使用下面代码代替即可

let beizer:UIBezierPath = UIBezierPath(roundedRect: btn5.bounds, byRoundingCorners: [UIRectCorner.TopLeft,UIRectCorner.TopRight], cornerRadii: CGSize(width: 15, height: 15))