每次点击按钮时执行一个方法

Question

I have the following extension in my Swift buttons :

extension UIButton {
    func backgroundChange() {
        let colorAnimation = CABasicAnimation(keyPath: "backgroundColor")
        colorAnimation.duration = 0.3
        colorAnimation.isAdditive = true
        colorAnimation.fromValue = UIColor.black.cgColor
        colorAnimation.toValue = self.layer.backgroundColor
        colorAnimation.repeatCount = 1
        colorAnimation.autoreverses = true
        layer.add(colorAnimation, forKey: nil)

    }
}

Which basically just triggers a "flash" animation in the button. The thing is, I have to manually call this method every time I want this to happen.

What should I modify on this so this happens for the class itself whenever you tap a button? Or, to put things differently, how can I override an "onClick" method common for all UIButtons so they all flash automatically when tapped?

EDIT: Users have flagged this question as a duplicate. But ITS NOT. The question they have linked does not answer my question AT ALL.

I found the right approach. This is the way to go :

override func touchesBegan(_ touches: Set<UITouch>, with: UIEvent?){
        backgroundChange()
        super.touchesBegan(touches as! Set<UITouch>, with: with)
    }

Answer 1

You need to create a subclass like

class CustomButton: UIButton {

override func touchesBegan(_ touches: Set<UITouch>, with: UIEvent?){
    backgroundChange()
    super.touchesBegan(touches as! Set<UITouch>, with: with)
}

func backgroundChange() {
    let colorAnimation = CABasicAnimation(keyPath: "backgroundColor")
    colorAnimation.duration = 0.3
    colorAnimation.isAdditive = true
    colorAnimation.fromValue = UIColor.black.cgColor
    colorAnimation.toValue = self.layer.backgroundColor
    colorAnimation.repeatCount = 1
    colorAnimation.autoreverses = true
    layer.add(colorAnimation, forKey: nil)

 }
}

then assign it to any button class in IB

Answer 2

Much easier -

@IBAction func keyPressed(_ sender: UIButton) {
  //button Title is sound.wav filename
  playSound(soundName: sender.currentTitle!) 
  //Reduces the sender's (the button that got pressed) opacity to half.
  sender.alpha = 0.5
  //the following 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, thus completing the "blink" effect on press
    sender.alpha = 1.0
  }
}