仅在游戏开始 Unity 3D 时实例化对象一次

Question

我有一个游戏有几个关卡，每个关卡有6个场景，游戏直接开始，没有任何菜单场景，当玩家打开游戏时，他可以从他已经到达的最后一个场景继续。

我只想在游戏开始时实例化一些元素（如最佳得分、点击播放等...），我的意思是它们应该被实例化在游戏开始时只有一次（在他达到的级别上）。

我在 GameManager 中尝试了这段代码，但它实例化了每个场景中的元素：

public GameObject PlayButton;

bool GameHasEnded = false;
public float RestartDelay = 2f;
public float NextLevelDelay = 5f;

public int level_index;
private static bool loaded = false;


private void Start()
{
    if (!loaded)
    {
        loaded = true;
        level_index = PlayerPrefs.GetInt("Last_Level");
        SceneManager.LoadScene(level_index);
    }

    GameObject canvas = GameObject.Find("Canvas");
    GameObject play = Instantiate(PlayButton, canvas.transform.position, Quaternion.identity);
    play.transform.SetParent(canvas.transform, false);
}

public void CompleteLevel()
{
    Invoke("NextLevel", NextLevelDelay);
}

public void EndGame()
{
    if (GameHasEnded == false)
    {
        GameHasEnded = true;
        Invoke("Restart", RestartDelay);
    }
}

void NextLevel()
{
    SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex +1);
    level_index = SceneManager.GetActiveScene().buildIndex + 1;
    PlayerPrefs.SetInt("Last_Level", level_index);
    PlayerPrefs.Save();
}

void Restart()
{
    SceneManager.LoadScene(SceneManager.GetActiveScene().path);
}

Answer 1

你已经有一个带有static标志loaded的if块

既然你在那里加载另一个场景，你需要一个类似的第二个标志，例如

private static bool loadedPrefab = false;

private void Start()
{
    if (!loaded)
    {
        loaded = true;
        level_index = PlayerPrefs.GetInt("Last_Level");
        SceneManager.LoadScene(level_index);

        // Return because you don't want to execute the rest yet
        // but instead in the new loaded scene
        return;
    }

    // The same way skip if the prefab was already loaded before
    if(!loadedPrefab)
    {
        loadedPrefab = true;

        GameObject canvas = GameObject.Find("Canvas");
        GameObject play = Instantiate(PlayButton, canvas.transform.position, Quaternion.identity);
        play.transform.SetParent(canvas.transform, false);
    }
}