20230522

blog0.swift

box.layer.cornerRadius = 20;
box.layer.masksToBounds = true;

blog1.swift

extension UIView {
   func roundCorners(corners: UIRectCorner, radius: CGFloat) {
        let path = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
        let mask = CAShapeLayer()
        mask.path = path.cgPath
        layer.mask = mask
    }
}

blog2.swift

box.roundCorners(corners: [.topLeft, .topRight], radius: 20.0)

blog3.swift

box.roundCorners(corners: [.topLeft, .bottomRight], radius: 20.0)

blog4.swift

box.roundCorners(corners: [.bottomLeft, .bottomRight], radius: 20.0)