swift] button 터치시 투명도 조절하기 (hover st..)

www.codegrepper.com/code-examples/swift/change+opacity+of+button+clicked+swift

IBAction func keyPressed(_ sender: UIButton) {

        sender.alpha = 0.5
        
        //Code should execute after 0.2 second delay.
        DispatchQueue.main.asyncAfter(deadline: .now() + 0.2) {
            //Bring's sender's opacity back up to fully opaque.
            sender.alpha = 1.0
        }
        
    }