# 1 读取字节流 FileStream     安卓平台下不能用

```csharp
/// <summary>
/// 读取本地文件到byte数组
/// </summary>
/// <param name="path"></param>
/// <returns></returns>
public byte[] GetBuffer(string path)
{
    byte[] buffer = null;

    using (FileStream fs = new FileStream(path, FileMode.Open))
    {
        buffer = new byte[fs.Length];
        fs.Read(buffer, 0, buffer.Length);
    }
    return buffer;
}

2 编辑器模式下   File 类 文件拷贝 安卓平台下不能用

/// <summary>
/// 拷贝文件夹
/// </summary>
/// <param name="sourceDirName"></param>
/// <param name="destDirName"></param>
public static void CopyDirectory(string sourceDirName, string destDirName)
{
    try
    {
        if (!Directory.Exists(destDirName))
        {
            Directory.CreateDirectory(destDirName);
            File.SetAttributes(destDirName, File.GetAttributes(sourceDirName));

        }

        if (destDirName[destDirName.Length - 1] != Path.DirectorySeparatorChar)
            destDirName = destDirName + Path.DirectorySeparatorChar;

        string[] files = Directory.GetFiles(sourceDirName);
        foreach (string file in files)
        {
            if (File.Exists(destDirName + Path.GetFileName(file)))
                continue;
            FileInfo fileInfo = new FileInfo(file);
            if (fileInfo.Extension.Equals(".meta", StringComparison.CurrentCultureIgnoreCase))
                continue;

            File.Copy(file, destDirName + Path.GetFileName(file), true);
            File.SetAttributes(destDirName + Path.GetFileName(file), FileAttributes.Normal);
        }

        string[] dirs = Directory.GetDirectories(sourceDirName);
        foreach (string dir in dirs)
        {
            CopyDirectory(dir, destDirName + Path.GetFileName(dir));
        }
    }
    catch (Exception ex)
    {
        throw ex;
    }
}

2 使用  WWW 方式读取    发布安卓后可用

using (WWW www = new WWW(fileUrl)) 
{
    yield return www;
    if (www.error == null)
    {
        if (onReadStreamingAssetOver != null)
        {
            onReadStreamingAssetOver(Encoding.UTF8.GetString(www.bytes));
        }
    }
    else
    {
        onReadStreamingAssetOver("");
    }
}

string s = Application.streamingAssetsPath + "/s/ss.txt";

string filePath = Application.persistentDataPath + "/s";

if (!File.Exists(filePath + "/ss.txt"))
{
    using (WWW www = new WWW(s))
    {
        yield return www;
        if (!string.IsNullOrEmpty(www.error))
        {
            Debug.Log(www.error);
        }
        else
        {
            if (!Directory.Exists(filePath))
            {
                //创建文件夹
                Directory.CreateDirectory(filePath);
            }
            File.WriteAllBytes(filePath + "/ss.txt", www.bytes);
        }
    }
}

总结

无法使用File类和FileStream读取出字节流，但可以使用这些类创建文件。Directory类可以创建文件夹，WWW读取字节流并写入数据。