ios - swift 3 : How do you save a high score programmatically?

Question

我有一个增加分数的按钮，如果它是最高分，那么即使在应用程序关闭并再次打开后，该数字也会保存为最高分。

那部分工作正常，但在我重新打开应用程序并单击按钮后，我的高分被重置并变得等于分数。我认为这是因为我在应该调用我的 HighscoreDefault 时调用了我的 highscore 变量，但我不明白你如何访问该值......如果这就是问题的话。

如何在应用程序重新打开后防止高分变为低于自身的值？

import UIKit

class ViewController: UIViewController {

    let phrase = "Your Score: "
    var increasingNum = 0
    let otherphrase = "High Score: "
    var highscore = 0
    var label: UILabel?
    var otherlabel: UILabel?
    let HighscoreDefault = UserDefaults.standard

    override func viewDidLoad() {

        super.viewDidLoad()

        let label = UILabel(frame: CGRect(x: self.view.frame.size.width / 2 - 100, y: 100, width: 200, height: 20))
        label.textAlignment = .center
        label.text = "\(phrase) \(increasingNum)"
        self.view.addSubview(label)
        self.label = label

        let otherlabel = UILabel(frame: CGRect(x: self.view.frame.size.width / 2 - 100, y: 200, width: 200, height: 20))
        otherlabel.textAlignment = .center
        otherlabel.text = "\(otherphrase) \(highscore)"
        self.view.addSubview(otherlabel)
        self.otherlabel = otherlabel

        let button = UIButton(frame: CGRect(x: self.view.frame.size.width / 2 - 150, y: self.view.frame.size.height / 2 - 50, width: 300, height: 100))
        button.backgroundColor = UIColor.cyan
        button.addTarget(self, action: #selector(scoreGoUp), for: .touchUpInside)
        self.view.addSubview(button)

        if let highscore = HighscoreDefault.value(forKey: "highscore") {

            otherlabel.text = "\(otherphrase) \(highscore)"
        }
    }

    func scoreGoUp (sender: UIButton){

        increasingNum += 1
        self.label?.text = "\(phrase) \(increasingNum)"
        if (increasingNum > highscore){

            highscore = increasingNum
            self.otherlabel?.text = "\(otherphrase) \(highscore)"
            HighscoreDefault.set(highscore, forKey: "highscore")
        }
    }
}

Answer 1

在我看来，保存 highscore 最方便的方法是实现一个计算变量，如下所示:

var highScore: Int {
    get {
        return UserDefaults.standard.integer(forKey: "highScore")
    }
    set {
        UserDefaults.standard.set(newValue, forKey: "highScore")
    }
}

这样，在您的 Controller 或单例中拥有该变量后，您就不会费心去考虑 UserDefaults。