文件分块上传 生成多个part文件 如何合并能 求大神指教

private string WriteTempFile(HttpPostedFile uploadFile, int chunk)

    {



        string tempDir = FileHelper.GetTempPath();

        if (!Directory.Exists(tempDir))

        {

            Directory.CreateDirectory(tempDir);

        }

        string fullName = string.Format("{0}\\{1}.part", tempDir, uploadFile.FileName);

        if (chunk == 0)

        {

            //如果是第一个分块，则直接保存



            uploadFile.SaveAs(fullName);

        }

        else

        {

            //如果是其他分块文件 ，则原来的分块文件，读取流，然后文件最后写入相应的字节

            FileStream fs = new FileStream(fullName, FileMode.Append);

            if (uploadFile.ContentLength > 0)

            {

                int FileLen = uploadFile.ContentLength;

                byte[] input = new byte[FileLen];



                // Initialize the stream.

                System.IO.Stream MyStream = uploadFile.InputStream;



                // Read the file into the byte array.

                MyStream.Read(input, 0, FileLen);



                fs.Write(input, 0, FileLen);

                fs.Close();

            }

        }





        return fullName;

    }