TIPS-Implement a Resumable FTP Download with .NET 2.0

   1:  //產生FTP Script檔案

   2:  string ftpScriptFile = Server.MapPath("TempFolder\\ftp.script");

   3:  Process p = new Process();

   4:  StreamWriter sw = 

   5:      new StreamWriter(ftpScriptFile);

   6:  sw.WriteLine("username");

   7:  sw.WriteLine("password");

   8:  sw.WriteLine("bin");

   9:  sw.WriteLine("cd /download");

  10:  sw.WriteLine("get some.zip");

  11:  sw.WriteLine("quit");

  12:  sw.Close();

  13:  //呼叫FTP command line utility

  14:  p.StartInfo = new ProcessStartInfo("cmd.exe", 

  15:  "/c ftp -s:\"" + ftpScriptFile + "\" ftp.darkthread.net");

  16:  //不顯示FTP Cmd視窗

  17:  p.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;

  18:  p.Start();

  19:  p.WaitForExit();

  20:  //狡兔死 走狗烹 Script檔刪除

  21:  File.Delete(ftpScriptFile);

   1:  private void test()

   2:  {

   3:      //宣告FTP連線

   4:      FtpWebRequest ftpReq = (FtpWebRequest)

   5:          WebRequest.Create("ftp://ftp.darkthread.net/download/some.zip");

   6:      //下載檔案

   7:      ftpReq.Method = WebRequestMethods.Ftp.DownloadFile;

   8:      //指定Username/Password

   9:      ftpReq.Credentials = new NetworkCredential("username", "password");

  10:      //指定BIN模式

  11:      ftpReq.UseBinary = true;

  12:      string zipFile = "c:\\temp\some.zip";

  13:      //支援續傳功能

  14:      FileInfo fi = new FileInfo(zipFile);

  15:      FileStream fs = null;

  16:      //檢測檔案是否存在

  17:      if (fi.Exists)

  18:      {

  19:          //檔案若存在，由剛才的中斷點繼續

  20:          ftpReq.ContentOffset = fi.Length;

  21:          fs = new FileStream(zipFile, FileMode.Append, FileAccess.Write);

  22:      }

  23:      else //檔案不存在時重新建立新檔案

  24:          fs = new FileStream(zipFile, FileMode.Create, FileAccess.Write);

  25:      //建立FTP連線

  26:      FtpWebResponse ftpResp = (FtpWebResponse)ftpReq.GetResponse();

  27:      //取得下載用的Stream物件

  28:      using (Stream stm = ftpResp.GetResponseStream())

  29:      {

  30:          //由於檔案龐大，以Block方式多批寫入

  31:          byte[] buff = new byte[2048];

  32:          int len = 0;

  33:          while (fs.Length < ftpResp.ContentLength)

  34:          {

  35:              //取得資料長度

  36:              len = stm.Read(buff, 0, buff.Length);

  37:              fs.Write(buff, 0, len);

  38:          }

  39:          stm.Close();

  40:   

  41:      }

  42:      fs.Flush();

  43:      fs.Close();

  44:  }