Round Top Corners of a UIButton in Swift

Question

I know I can round all four corners using:

 myBtn.layer.cornerRadius = 8
 myBtn.layer.masksToBounds = true

Since I only want to round two,

Answer 1

For swift 5 and the most flexibility

Define an extension with a roundCorners function

extension UIButton {
    func roundCorners(corners: UIRectCorner, radius: Int = 8) {
        let maskPath1 = UIBezierPath(roundedRect: bounds,
                                     byRoundingCorners: corners,
                                     cornerRadii: CGSize(width: radius, height: radius))
        let maskLayer1 = CAShapeLayer()
        maskLayer1.frame = bounds
        maskLayer1.path = maskPath1.cgPath
        layer.mask = maskLayer1
    }
}

Call the roundCorners function

myButton.roundCorners(corners: [.topLeft, .topRight])

Or with a specific radius

myButton.roundCorners(corners: [.topLeft, .topRight], radius: 20)