//ftp的上傳功能
    private void Upload(string filename)
    {
        FileInfo fileInf = new FileInfo(filename);

        string uri = "ftp://" + ftpServerIP + "/" + fileInf.Name;
        FtpWebRequest reqFTP;

        // 根據uri建立FtpWebRequest物件
        reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/" + fileInf.Name));

        // ftp使用者名稱和密碼
        reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);

        // 預設為true，連線不會被關閉
        // 在一個命令之後被執行
        reqFTP.KeepAlive = false;

        // 指定執行什麼命令
        reqFTP.Method = WebRequestMethods.Ftp.UploadFile;

        // 指定資料傳輸型別
        reqFTP.UseBinary = true;

        // 上傳檔案時通知伺服器檔案的大小
        reqFTP.ContentLength = fileInf.Length;

        // 緩衝大小設定為2kb
        int buffLength = 2048;

        byte[] buff = new byte[buffLength];
        int contentLen;

        // 開啟一個檔案流 (System.IO.FileStream) 去讀上傳的檔案
        FileStream fs = fileInf.OpenRead();
        try
        {
            // 把上傳的檔案寫入流
            Stream strm = reqFTP.GetRequestStream();

            // 每次讀檔案流的2kb
            contentLen = fs.Read(buff, 0, buffLength);

            // 流內容沒有結束
            while (contentLen != 0)
            {
                // 把內容從file stream 寫入 upload stream
                strm.Write(buff, 0, contentLen);

                contentLen = fs.Read(buff, 0, buffLength);
            }

            // 關閉兩個流
            strm.Close();
            fs.Close();
        }
        catch (Exception ex)
        {
           // MessageBox.Show(ex.Message, "Upload Error");
            Response.Write("Upload Error：" + ex.Message);
        }
    }

    //從ftp伺服器上下載檔案的功能
    private void Download(string filePath, string fileName)
    {
        FtpWebRequest reqFTP;

        try
        {
            FileStream outputStream = new FileStream(filePath + "//" + fileName, FileMode.Create);

            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/" + fileName));

            reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;

            reqFTP.UseBinary = true;

            reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);

            FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();

            Stream ftpStream = response.GetResponseStream();

            long cl = response.ContentLength;

            int bufferSize = 2048;

            int readCount;

            byte[] buffer = new byte[bufferSize];

            readCount = ftpStream.Read(buffer, 0, bufferSize);

            while (readCount > 0)
            {
                outputStream.Write(buffer, 0, readCount);

                readCount = ftpStream.Read(buffer, 0, bufferSize);
            }

            ftpStream.Close();

            outputStream.Close();

            response.Close();
        }
        catch (Exception ex)
        {
            Response.Write("Download Error：" + ex.Message);
        }
    }

    //從ftp伺服器上獲得檔案列表
    public string[] GetFileList()
    {
        string[] downloadFiles;
        StringBuilder result = new StringBuilder();
        FtpWebRequest reqFTP;
       // HttpWebRequest reqFTP;
        try
        {
            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/"));
            reqFTP.UseBinary = true;
            reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
            reqFTP.Method = WebRequestMethods.Ftp.ListDirectory;
            WebResponse response = reqFTP.GetResponse();
            StreamReader reader = new StreamReader(response.GetResponseStream());
            string line = reader.ReadLine();
            while (line != null)
            {
                result.Append(line);
                result.Append("/n");
                line = reader.ReadLine();
            }
            // to remove the trailing '/n'       
            result.Remove(result.ToString().LastIndexOf('/n'), 1);
            reader.Close();
            response.Close();
            return result.ToString().Split('/n');
        }
        catch (Exception ex)
        {
            System.Windows.Forms.MessageBox.Show(ex.Message);
            downloadFiles = null;
            return downloadFiles;
        }
    }