Swift 3：如何以编程方式保存高分？

Question

我有一个增加分数的按钮，如果它是最高分数，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数。

这部分工作正常，但是在我重新打开应用程序并单击按钮后，我的高分被重置并等于分数。我认为这是因为当我应该调用我的 HighscoreDefault 时我调用了我的 highscore 变量，但我不知道你如何访问该值......如果这甚至是问题。

重新打开应用后，如何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这样的计算变量：

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

这样，在控制器或单例中拥有该变量后，您就不会再考虑 UserDefaults 了。

Answer 2

代替

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

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

在 ViewDidLoad 的代码中添加这一行

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

        otherlabel.text = "\(otherphrase) \(highscore)"
        self.highscore = highscore as! Int
    }

Answer 3

当您重新打开您的应用程序时，UserDefault's 可能会保存您的 highScore 但 您的代码没有将其分配给您的 ViewController's highscore 变量

if let highscore = HighscoreDefault.value(forKey: "highscore") as? Int {
        self.highscore = highscore
        otherlabel.text = "\(otherphrase) \(highscore)"
}

Answer 4

highscore 默认值为 0，因此每次第一次调用 if (increasingNum > highscore) 的操作应始终为 true。您需要在代码中的某处执行什么操作才能将您的 HighscoreDefault.value(forKey: "highscore") as? Int 分配给 highscore：

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") as? Int {
        // here is the extra job!!
        self.highscore = highscore
        otherlabel.text = "\(otherphrase) \(highscore)"
    }
}

希望对您有所帮助。

Answer 5

在这里初始化你的高分：

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

    otherlabel.text = "\(otherphrase) \(highscore)"
    // you should get your highscore here               
    highscore = highscoreLast

    }

Answer 6

highscore 必须是 int 而非 int 的数组
你应该对这个数组进行排序（升序或降序） 如果新分数 > 数组中的最小项目和 array.count > 你的高核心默认计数 - > 你用新分数更改这个项目。并保存它们
if array.count