How to upload many text files from local computer to ftp using c# .net windows service?

private void button1_Click(object sender, EventArgs e)
 {
	List fileInfo= // Store list of files to be uploaded.
	Parallel.ForEach(fileInfo, objFile =>
                                                              {
                                                                  UploadFile(objFile);
                                                              });
}


private bool UploadFile(FileInfo fileInfo)
        {
            FtpWebRequest request = null;
            try
            {
                string ftpPath = "ftp://www.tt.com/" + fileInfo.Name
                request = (FtpWebRequest)WebRequest.Create(ftpPath);
                request.Credentials = new NetworkCredential("ftptest", "ftptest");  // username , password
                request.Method = WebRequestMethods.Ftp.UploadFile;
                request.KeepAlive = false;
                request.Timeout = 60000; // 1 minute time out
                request.ServicePoint.ConnectionLimit = 15; // Connection limit 15 with the ftp., By default 2, -1 means infinite.

                byte[] buffer = new byte[1024];
                using (FileStream fs = new FileStream(fileInfo.FullPath, FileMode.Open))
                {
                    int dataLength = (int)fs.Length;
                    int bytesRead = 0;
                    int bytesDownloaded = 0;
                    using (Stream requestStream = request.GetRequestStream())
                    {
                        while (bytesRead < dataLength)
                        {
                            bytesDownloaded = fs.Read(buffer, 0, buffer.Length);
                            bytesRead = bytesRead + bytesDownloaded;
                            requestStream.Write(buffer, 0, bytesDownloaded);
                        }
                        requestStream.Close();
                    }
                }
                return true;
            }
            catch (Exception ex)
            {
                throw ex;                
            }
            finally
            {
                request = null;
            }
            return false;
        }// UploadFile