c# byte转docx

public string ByteConvertWord(byte[] data, string fileName)
        {
            string savePath = @"\\" + fileName + ".docx";
            string filePath = Application.StartupPath + savePath;
            FileStream fs;
            if (System.IO.File.Exists(filePath))
            {
                fs = new FileStream(filePath, FileMode.Truncate);
            }
            else
            {
                fs = new FileStream(filePath, FileMode.CreateNew);
            }
            BinaryWriter br = new BinaryWriter(fs);
            br.Write(data, 0, data.Length);
            br.Close();
            fs.Close();
            return filePath;
        }