Assets\\FPS\\Audio\\Soundtrack\\MusicManager.cs(35,70)：错误 CS0841：在声明之前不能使用局部变量“currentScene”

Question

I'm building this game, and I've been trying to fix a bug for very long, so I came here for some help...

These are the errors I'm getting:

1. error CS0841: Cannot use local variable 'currentScene' before it is declared
2. The Type or namespace 'Scene' could not be found (are you missing a using directive or an 3. assembly reference?)
3. The name 'SceneManager' does not exist in the current context

using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManager;

public class MusicManager : MonoBehaviour
{
    private AudioSource audiosource;
    public AudioClip[] songs;
    public float volume;
    [SerializeField] private float songsPlayed;
    [SerializeField] private bool[] beenPlayed;

    List<string> DontChangeSongScenes = new List<string>();

    // Start is called before the first frame update
    void Start()
    {
        Scene currentScene = SceneManager.GetActiveScene();

        audiosource = GetComponent<AudioSource>();

        beenPlayed = new bool[songs.Length];

        if (!audiosource.isPlaying || !DontChangeSongScenes.Contains(currentScene.name))
            ChangeSong(Random.Range(0, songs.Length));

        DontChangeSongScenes.Add("Scene_1"); /*just copy and paste this line and instead 
        of "Scene_1" write the name of the scene that shouldnt change the current playing song. */
        DontChangeSongScenes.Add("Scene_2");
    }

    // Update is called once per frame
    void Update()
    {
        audiosource.volume = volume;

        if (!audiosource.isPlaying || !DontChangeSongScenes.Contains(currentScene.name))
            ChangeSong(Random.Range(0, songs.Length));

        if (songsPlayed == songs.Length)
        {
            songsPlayed = 0;
            for (int i = 0; i < songs.Length; i++)
            {
                if (i == songs.Length)
                    break;
                else
                    beenPlayed[i] = false;
            }
        }



    }



    public void ChangeSong(int songPicked)
    {

        if (!beenPlayed[songPicked])
        {
            songsPlayed++;
            beenPlayed[songPicked] = true;
            audiosource.clip = songs[songPicked];
            audiosource.Play();
        }
        else
            audiosource.Stop();
    }

    void Awake()
    {
        DontDestroyOnLoad(transform.gameObject);
    }
}
  

Answer 1

The error is very clear. In your Update method you have not declared currentScene . You could add it as a class field, or grab it each frame.

    // Update is called once per frame
    void Update()
    {
        Scene currentScene = SceneManager.GetActiveScene();
        audiosource.volume = volume;

        if (!audiosource.isPlaying || !DontChangeSongScenes.Contains(currentScene.name))
            ChangeSong(Random.Range(0, songs.Length));

2. & 3.

The namespace is SceneManagement , not SceneManager .

using UnityEngine.SceneManagement;

https://docs.unity3d.com/ScriptReference/SceneManagement.Scene.html