我的倒数计时器卡住了，游戏没有停止

Question

我正在尝试创建一个倒计时计时器，用于当我的玩家在游戏再次开始前 3 秒购买第二条生命时。我不确定我需要在下面修复什么才能使其正常工作。目前，所有的 UI 都会在应有的时候弹出，倒数计时器文本也确实会弹出，但游戏继续进行，并且计时器停留在 3。

public static bool GameOver = false;
public static bool CountDown = false;

public GameObject deathMenuUI;
public GameObject countDownUI;

public int timeLeft = 3;
public Text countDownText;

public float slowness = 10f;

public void Start()
{
    PlayerPrefs.SetInt("Score", 0);
    Time.timeScale = 1f;
}

public void EndGame()
{
    StartCoroutine(DeathScreen());
}
//on death, slow time for one second and open deathscreen UI
IEnumerator DeathScreen()
{
    Time.timeScale = 1f / slowness;
    Time.fixedDeltaTime = Time.fixedDeltaTime / slowness;

    yield return new WaitForSeconds(1f / slowness);

    Time.timeScale = 1f;
    Time.fixedDeltaTime = Time.fixedDeltaTime * slowness;

    deathMenuUI.SetActive(true);
    Time.timeScale = 0f;
    GameOver = true;
}
//if game is continued, close deathUI and start timer
public void continueGame()
{
    deathMenuUI.SetActive(false);
    Time.timeScale = 1f;
    GameOver = false;
    StartCoroutine(LoseTime());
}
private void Update()
{
    countDownText.text = ("" + timeLeft);
    if (timeLeft <= 0)
    {
        StopCoroutine(LoseTime());
    }
}
IEnumerator LoseTime()
{
    while (true)
    {
        countDownUI.SetActive(true);
        CountDown = true;
        yield return new WaitForSeconds(1);
        timeLeft--;
    }
}

}

Answer 1

既然你设置了Time.timeScale = 0 来暂停你的游戏，那么你需要使用WaitForSecondsRealtime 而不是WaitForSeconds（就像@Prodian 在评论部分建议的那样）因为WaitForSecondsRealtime 使用未缩放的时间，无论什么值都不会受到影响您将Time.timeScale 设置为。

我在这里对您的代码进行了一些修改：

//if game is continued, close deathUI and start timer
public void continueGame()
{
    // Add this line to prevent accident like double click... which will start multiple coroutine and cause unexpected result
    if (CountDown) return;
    CountDown = true;
    deathMenuUI.SetActive(false);
    // Since you want your game to still being paused for 3 seconds before resuming
    Time.timeScale = 0;
    StartCoroutine(LoseTime());
}

private void AfterCountdownFinished()
{
    // important. You must set your Time.timeScale back to its default value
    // because even if you reload your scene the timeScale remain the same which can cause you to encounter freeze error which you might spend time to search for the problem

    Time.timeScale = 1;
    GameOver = CountDown = false;
    countDownUI.SetActive(false);
    // You want to write your restart/continue logic here
    // Example:
    // reload the level
    // SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex);
}

IEnumerator LoseTime()
{
    // I forgot this part (which you pointed out)
    countDownUI.SetActive(true);
    // Here is how you can improve performance

    // It seems you can't create and reuse it like WaitForSeconds
    // var delay = new WaitForSecondsRealtime(1);
    // Set this the text here so it will display (3 in your case) for 1 second before start decreasing
    countDownText.text = timeLeft.ToString();

    // If your level will restart after the countdown ends then you don't need to create another variable like below. You can just use timeLeft directly
    int time = timeLeft;
    while (time > 0)
    {
        // Edited here
        yield return new WaitForSecondsRealtime(1);
        time--;
        // Here you don't set your UI text every frame in the update but you only set it only when there is change on timeLeft
        countDownText.text = time.ToString();
    }
    // When countdown ended. You don't need to call StopCoroutine
    AfterCountdownFinished();
}

如果您的 UI 有某种使用 Time.deltaTime 进行动画处理的动画，那么您需要将其更改为使用 Time.unscaledDeltaTime。与WaitForSeconds 和WaitForSecondsRealtime 的思路相同，一个受Time.timeScale 值影响，另一个不受。

PS：我完全删除了你的Update 函数，因为如果你按照我的方式实现你就不需要它了。而且您无需在任何地方致电StopCoroutine，因为倒计时结束时会自动停止