1、StreamWriter和StreamReader 流写入和读取

 public void CreatFile(string path)
    {
        if (!System.IO.File.Exists(path))
        {
            WriteFile(path);
        }
    }
    /// <summary>
    /// path需要包含文件的后缀名
    /// </summary>
    /// <param name="path">路径</param>
    /// <param name="con">需要写入的数据</param>
    public void WriteFile(string path, string con = "")
    {
        string str = con;
        //若是直接在文件里添加数据，则采用重写方法，将append设置为true
        var file = new StreamWriter(path, true);
        //var file = new StreamWriter(path);
        //file.WriteLine(str);
        file.Write(str);
        file.Close();
    }
    /// <summary>
    /// path需要包含文件的后缀名
    /// </summary>
    /// <param name="path"></param>
    public void ReadFile(string path)
    {
        using (StreamReader file = new StreamReader(path))
        {
            string fileContents = file.ReadToEnd();
            Debug.Log("读取文件内容：" + fileContents);
            file.Close();
        }
    }

2 、WWW读取文件，当文件属于StreamingAssets文件夹时,可直接读取txt和xlsx,以及csv

 //地址前面需要加上file://
 path = "file://" + Application.streamingAssetsPath + "/test.txt";
 ReadByWWW(path);
 public void ReadByWWW(string path)
    {
        StartCoroutine(LoadWWW(path));
    }

    IEnumerator LoadWWW(string path)
    {
        WWW ww = new WWW(path);
        yield return ww;
        if (ww.error == null)
        {
            Debug.Log("" + ww.text.ToString());
        }
        else
        {
            Debug.Log(ww.error.ToString());
        }

    }

3、
打开文件，直接用FileStream，若是没有该文件则直接创建，path都需加后缀名

  public void OpenFile(string path)
    {
        FileStream aFile = new FileStream(path, FileMode.OpenOrCreate);
        using (StreamReader file = new StreamReader(aFile))
        {
            string fileContents = file.ReadToEnd();
            Debug.Log("读取文件内容：" + fileContents);
            file.Close();
        }
    }
 public void WriteFile(string path)
    {
        FileStream aFile = new FileStream(path, FileMode.OpenOrCreate);
        StreamWriter sw = new StreamWriter(aFile);
        sw.WriteLine("写入测试");
        sw.Close();

    }