ios - 等待 Swift 计时器完成

Question

所以我在 swift 5 上做一个简单的游戏，我基本上有一个 3..2..1.. go 计时器来开始游戏，然后有一个 3..2..1..stop 计时器来停止游戏。最后是一个显示分数的函数。我需要一种方法让每个函数调用在下一个开始之前等待计时器完成，有什么建议吗？到目前为止，这是我的代码。 (此外，如果您对应用程序有任何其他建议，也请告诉我，最终目标是记录您可以在 3 秒内点击按钮的次数)

var seconds = 3 //Starting seconds
var countDownTimer = Timer()
var gameTimer = Timer()
var numberOfTaps = 0

override func viewDidLoad() {
    super.viewDidLoad()

    self.startCountdown(seconds: seconds)
    self.gameCountdown(seconds: seconds)
    self.displayFinalScore()


}

func startCountdown(seconds: Int) {
        countDownTimer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { [weak self] timer in
            self?.seconds -= 1
            if self?.seconds == 0 {
                self?.countdownLabel.text = "Go!"
                timer.invalidate()
            } else if let seconds = self?.seconds {
                self?.countdownLabel.text = "\(seconds)"
            }
        }
}

func gameCountdown(seconds: Int) {
        gameTimer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { [weak self] timer in
              self?.seconds -= 1
              if self?.seconds == 0 {
                  self?.countdownLabel.text = "Stop!"
                  timer.invalidate()
              } else if let seconds = self?.seconds {
                  self?.countdownLabel.text = "\(seconds)"
              }
          }
  }


    deinit {
        // ViewController going away.  Kill the timer.
        countDownTimer.invalidate()
    }




@IBOutlet weak var countdownLabel: UILabel!


@IBAction func tapMeButtonPressed(_ sender: UIButton) {
    if gameTimer.isValid {
        numberOfTaps += 1
    }
}

func displayFinalScore() {
    if !gameTimer.isValid && !countDownTimer.isValid {
        countdownLabel.text = "\(numberOfTaps)"
    }
}

Answer 1

您应该考虑您的游戏可能处于的状态。它可能是 -

设置 - 建立游戏

开始 - 前三秒

正在运行 - 在前三秒之后但在结束之前

结束 - 最后三秒

结束 - 时间到了。

每次你的计时器滴答作响时，你都需要考虑你需要采取什么行动以及你需要移动到什么状态。您还没有说您希望游戏持续多长时间，但假设是 30 秒。

当一个新游戏开始时，你在 setup状态;该按钮被禁用(即它不会对点击使用react)并且您将分数设置为 0。您移动到 ​​ starting状态。
在 starting你显示倒计时。三秒钟后，您启用按钮并进入 running状态。
达到 27 秒后，您将进入 ending状态并显示结束倒计时
终于时间到了，你进入 ended状态，禁用按钮并显示分数。

你可以这样编码

enum GameState {

    case setup
    case starting
    case running
    case ending
    case ended
}

class ViewController: UIViewController {

    @IBOutlet weak var startButton: UIButton!
    @IBOutlet weak var tapButton: UIButton!
    @IBOutlet weak var countdownLabel: UILabel!

    var gameState = GameState.ended
    var gameTimer:Timer?
    var numberOfTaps = 0
    var gameStartTime = Date.distantPast
    let GAMEDURATION: TimeInterval = 30

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
    }

    @IBAction func startButtonTapped(_ sender: UIButton) {
        self.startGame()
    }

    @IBAction func tapMeButtonPressed(_ sender: UIButton) {
        self.numberOfTaps += 1
    }

    func startGame() {
        self.gameState = .setup

        self.gameTimer = Timer.scheduledTimer(withTimeInterval:0.1, repeats: true) { timer in

            let elapsedTime = -self.gameStartTime.timeIntervalSinceNow
            let timeRemaining = self.GAMEDURATION-elapsedTime
            switch self.gameState {
            case .setup:
                self.gameStartTime = Date()
                self.tapButton.isEnabled = false
                self.startButton.isEnabled = false
                self.numberOfTaps = 0
                self.gameState = .starting
            case .starting:
                if elapsedTime > 2.5 {
                    self.gameState = .running
                    self.tapButton.isEnabled = true
                    self.countdownLabel.text  = "Go!"
                } else {
                    let countdown = Int(3-round(elapsedTime))
                    self.countdownLabel.text = "\(countdown)"
                }
            case .running:
                if timeRemaining < 4 {
                    self.gameState = .ending
                }
            case .ending:
                let countdown = Int(timeRemaining)
                self.countdownLabel.text = "\(countdown)"
                if timeRemaining < 1 {
                    self.countdownLabel.text = "Stop"
                    self.gameState = .ended
                    self.tapButton.isEnabled = false
                }
            case .ended:
                if timeRemaining <= 0 {
                    self.countdownLabel.text = "You tapped the button \(self.numberOfTaps) times"
                    self.startButton.isEnabled = true
                    self.gameTimer?.invalidate()
                    self.gameTimer = nil
                }
            }
        }
    }
}