setBackgroundImage不会更改按钮颜色吗？

Question

我如何实现setBackgroundImage来短暂更改特定按钮的背景，然后将其恢复为正常状态？

这是我的代码：

@IBAction func answerPressed（_发送者：UIButton）{

   if sender.tag == selectedAnswer{

       //Answer is correct so I'd like the button background to briefly turn green

       score += 1

    }
    else {

          //Answer is not correct so the background should turn red


        attempts -= 1

    }

    wordNumber += 1
    updateWord()

}