swift - 如何通过按下 UIbutton 来检查它是否是正确答案

Question

我在一个 4 选项问题中创建了 4 个 UI 按钮。这里的代码是检查是否选择了正确的答案。为什么 if 语句每次都返回 false？我知道这里出了问题，但我对 swift 很陌生，无法自己修复它。请帮忙，非常感谢!

let question1 = Question(question: "This was the only US President to serve more than two consecutive terms.", options: ["George Washington", "Woodrow Wilson", "Andrew Jackson", "Franklin D. Roosevelt"], correctAnswer: "Franklin D. Roosevelt")

@IBAction func checkAnswer(_ sender: UIButton) {

    let correctAnswer = question1.correctAnswer

    if sender.currentTitle == correctAnswer {
        sender.backgroundColor = UIColor.black
    }
}

Answer 1

设置选定(或更一般的正常状态)的按钮标题:

let btn = UIButton()
btn.setTitle("Franklin D. Roosevelt", for: .normal)
//Or
btn.setTitle("Franklin D. Roosevelt", for: .selected)

有关 currentTitle 的更多详细信息，请查看 here .