Opening FTP Read Streams

0

By Tom Hines on Dec 28th, 2011 8:35 pm

Here are two examples of opening read streams to files on an FTP server.
One example uses the FtpWebRequest method.
One example uses the WebClient method.

Here is a method of testing those functions:

using System;
using System.Diagnostics;
using System.IO;
using System.Net;

namespace UseFtpStreamExample
{
   using FtpReadStreams;
   class Program
   {
      static void Main(string[] args)
      {
         string strError = "";

         string strFtpUri =
#if !DEBUG
            "ftp://ftp.myServer.com/SomeFile.txt";
#else
            "ftp://download.textpad.com/welcome.msg";
#endif

         // Be sure to open an debug output window to see file contents
         if (!CFtpReadStream.DoWebRequestExample(strFtpUri, ref strError))
         {
            Trace.WriteLine("Could not read WR: " + strError);
            return;
         }

         // Be sure to open an debug output window to see file contents
         if (!CFtpReadStream.DoWebClientExample(strFtpUri, ref strError))
         {
            Trace.WriteLine("Could not read WC: " + strError);
            return;
         }

         Trace.WriteLine("Finished");
      }
   }
}

using System;
using System.Diagnostics;
using System.IO;
using System.Net;

namespace FtpReadStreams
{
   public class CFtpReadStream
   {
      /// <summary>
      /// Open a file for reading (as text) and display it in debug window.
      /// This example uses the WebClient
      /// </summary>
      /// <param name="strFtpUri">The full URI to the file</param>
      /// <param name="strError">ref to any errors returned</param>
      /// <returns>bool (true if success)</returns>
      public static bool DoWebClientExample(string strFtpUri, ref string strError)
      {
         bool blnRetVal = true;
         WebClient wc = new WebClient();
         try
         {
            using (StreamReader fileIn = new StreamReader(wc.OpenRead(strFtpUri)))
            {
               string strData = "";
               while (!fileIn.EndOfStream)
               {
                  strData = fileIn.ReadLine();
                  Trace.WriteLine(strData);
               }

               fileIn.Close();
            }
         }
         catch (Exception exc)
         {
            blnRetVal = false;
            strError = exc.Message;
         }

         return blnRetVal;
      }

      /// <summary>
      /// Open a file for reading (as text) and display it in debug window.
      /// This method uses the FtpWebRequest
      /// </summary>
      /// <param name="strFtpUri">The full URI to the file</param>
      /// <param name="strError">ref to any errors returned</param>
      /// <returns>bool (true if success)</returns>
      public static bool DoWebRequestExample(string strFtpUri, ref string strError)
      {
         bool blnRetVal = true;
         try
         {
            FtpWebRequest ftp = (FtpWebRequest)WebRequest.Create(strFtpUri);
            ftp.Method = WebRequestMethods.Ftp.DownloadFile;
            using (FtpWebResponse response = (FtpWebResponse)ftp.GetResponse())
            {
               using (StreamReader fileIn = new StreamReader(response.GetResponseStream()))
               {
                  string strData = "";
                  while (!fileIn.EndOfStream)
                  {
                     strData = fileIn.ReadLine();
                     Trace.WriteLine(strData);
                  }
                  //
                  fileIn.Close();
               }
               //
               response.Close();
            }
         }
         catch (Exception exc)
         {
            blnRetVal = false;
            strError = exc.Message;
         }

         return blnRetVal;
      }
   }
}