如何在切换到新的ViewController时自动运行代码？

Question

我有一个更新ViewController中两个标签的函数。我怎样才能做到这一点，一旦我切换到这个ViewController，这两个标签都会更新，而不需要用户输入，如按钮？

@IBOutlet weak var scoreLabel: UILabel!

@IBOutlet weak var highScoreLabel: UILabel!

func updateScores() {
    scoreLabel.text = "\(UserDefaults.standard.integer(forKey: "EndScore"))"
    if UserDefaults.standard.string(forKey: "LastGameMode") == "Easy" {
        highScoreLabel.text = "\(UserDefaults.standard.integer(forKey: "EasyHighScore"))"
    } else if UserDefaults.standard.string(forKey: "LastGameMode") == "Normal" {
        highScoreLabel.text = "\(UserDefaults.standard.integer(forKey: "NormalHighScore"))"
    } else if UserDefaults.standard.string(forKey: "LastGameMode") == "Hard" {
        highScoreLabel.text = "\(UserDefaults.standard.integer(forKey: "HardHighScore"))"
    }
}

Answer 1

您只需覆盖 viewWillAppear并在其中调用updateScores()。

您的代码应如下所示：

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    updateScores()
}