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Using StreamReader with sockets for the 2nd time

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Join Date: Jul 2009

Posts: 3

Reputation: fulcrum9 is an unknown quantity at this point

Solved Threads: 0

fulcrum9

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Newbie Poster

Using StreamReader with sockets for the 2nd time

Jul 31st, 2009

Hi everyone,

I have a problem with reading a socket for the 2nd time. I'll explain.
By using TcpClient I set up a connection to a webserver. Then I perform a GET request and read it out. When I do another GET request afterwards, that works, but I can't read the socket.

Somebody pls help me out.
If you find other small thingies in the code that are wrong you can tell me too. I'm just a beginner in C#.

Thanks in advance!

 Help with Code Tags 
 c# Syntax (Toggle Plain Text) 
TcpClient oTcpClient = new TcpClient();
            IAsyncResult oIAsyncResult = oTcpClient.BeginConnect("www.example.com", 80, null, null);
            bool success = oIAsyncResult.AsyncWaitHandle.WaitOne(5000, true);
            if (!success)
            {
                oTcpClient.Close();
                Console.WriteLine("Timeout...");
                return;
            }
            oTcpClient.EndConnect(oIAsyncResult);
 
            NetworkStream oNetworkStream = oTcpClient.GetStream();
            StreamReader oStreamReader = new StreamReader(oNetworkStream);
            StreamWriter oStreamWriter = new StreamWriter(oNetworkStream);
            oStreamWriter.AutoFlush = true;
 
oStreamWriter.Write("GET /index.php HTTP/1.1\r\n"
                + "Host: www.example.com\r\n"
                + "User-Agent: Mozilla/5.0\r\n"
                + "Connection: close\r\n"
                + "\r\n");
 
            string output = "";
            string src = "";
            while (output != null)
            {
                output = oStreamReader.ReadLine();
                if (output != null)
                {
                    src += output;
                }
            }
 
//here I do stuff with the src
 
oStreamWriter.Write("GET /index.php HTTP/1.1\r\n"
                + "Host: www.example.com\r\n"
                + "User-Agent: Mozilla/5.0\r\n"
                + "Connection: close\r\n"
                + "\r\n");
//starting from here it goes wrong
            string output = "";
            string src = "";
            while (output != null)
            {
                output = oStreamReader.ReadLine();
                if (output != null)
                {
                    src += output;
                }
            }
TcpClient oTcpClient = new TcpClient();
            IAsyncResult oIAsyncResult = oTcpClient.BeginConnect("www.example.com", 80, null, null);
            bool success = oIAsyncResult.AsyncWaitHandle.WaitOne(5000, true);
            if (!success)
            {
                oTcpClient.Close();
                Console.WriteLine("Timeout...");
                return;
            }
            oTcpClient.EndConnect(oIAsyncResult);

            NetworkStream oNetworkStream = oTcpClient.GetStream();
            StreamReader oStreamReader = new StreamReader(oNetworkStream);
            StreamWriter oStreamWriter = new StreamWriter(oNetworkStream);
            oStreamWriter.AutoFlush = true;

oStreamWriter.Write("GET /index.php HTTP/1.1\r\n"
                + "Host: www.example.com\r\n"
                + "User-Agent: Mozilla/5.0\r\n"
                + "Connection: close\r\n"
                + "\r\n");

            string output = "";
            string src = "";
            while (output != null)
            {
                output = oStreamReader.ReadLine();
                if (output != null)
                {
                    src += output;
                }
            }

//here I do stuff with the src

oStreamWriter.Write("GET /index.php HTTP/1.1\r\n"
                + "Host: www.example.com\r\n"
                + "User-Agent: Mozilla/5.0\r\n"
                + "Connection: close\r\n"
                + "\r\n");
//starting from here it goes wrong
            string output = "";
            string src = "";
            while (output != null)
            {
                output = oStreamReader.ReadLine();
                if (output != null)
                {
                    src += output;
                }
            }

•

Join Date: Jan 2008

Posts: 483

Reputation: DangerDev has a spectacular aura about

Solved Threads: 59

DangerDev

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Posting Pro in Training

Re: Using StreamReader with sockets for the 2nd time

Jul 31st, 2009

I dont think you can do this. Whenever you read some thing from stream you actually move the reader's position in the Stream. This will happen even if you use StreamReader. So if you have read the stream till end, reader's position is in end. Now if you want to read the stream again you have to set the reader position using seek() method of stream.
You can't call seek method in NetworkStream. As this method is not currently supported and always throws a NotSupportedException.

Freedom in the Mind, Faith in the words.. Pride in our Souls...
Indian Developer
http://falaque.wordpress.com/

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Join Date: Oct 2008

Posts: 2,721

Reputation: adatapost has much to be proud of

Solved Threads: 501

adatapost

Offline

Posting Maven

Re: Using StreamReader with sockets for the 2nd time

Jul 31st, 2009

I didn't find any problem in your code:

 Help with Code Tags 
 C# Syntax (Toggle Plain Text) 
TcpClient oTcpClient = new TcpClient();
IAsyncResult oIAsyncResult = oTcpClient.BeginConnect("www.daniweb.com", 80, null, null);
bool success = oIAsyncResult.AsyncWaitHandle.WaitOne(5000, true);
       if (!success)
        {
            oTcpClient.Close();
            Console.WriteLine("Timeout...");
            return;
        }
        oTcpClient.EndConnect(oIAsyncResult);
 
        NetworkStream oNetworkStream = oTcpClient.GetStream();
        StreamReader oStreamReader = new StreamReader(oNetworkStream);
        StreamWriter oStreamWriter = new StreamWriter(oNetworkStream);
        oStreamWriter.AutoFlush = true;
 
        oStreamWriter.Write("GET /forums/thread208224.html HTTP/1.1\r\n"
                        + "Host: www.daniweb.com\r\n"
                        + "User-Agent: Mozilla/5.0\r\n"
                        + "Connection: close\r\n"
                        + "\r\n");
 
        string output = "";
        string src = "";
        while (output != null)
        {
            output = oStreamReader.ReadLine();
            if (output != null)
            {
                src += output;
            }
        }
     Console.WriteLine(src);
TcpClient oTcpClient = new TcpClient();
IAsyncResult oIAsyncResult = oTcpClient.BeginConnect("www.daniweb.com", 80, null, null);
bool success = oIAsyncResult.AsyncWaitHandle.WaitOne(5000, true);
       if (!success)
        {
            oTcpClient.Close();
            Console.WriteLine("Timeout...");
            return;
        }
        oTcpClient.EndConnect(oIAsyncResult);

        NetworkStream oNetworkStream = oTcpClient.GetStream();
        StreamReader oStreamReader = new StreamReader(oNetworkStream);
        StreamWriter oStreamWriter = new StreamWriter(oNetworkStream);
        oStreamWriter.AutoFlush = true;

        oStreamWriter.Write("GET /forums/thread208224.html HTTP/1.1\r\n"
                        + "Host: www.daniweb.com\r\n"
                        + "User-Agent: Mozilla/5.0\r\n"
                        + "Connection: close\r\n"
                        + "\r\n");

        string output = "";
        string src = "";
        while (output != null)
        {
            output = oStreamReader.ReadLine();
            if (output != null)
            {
                src += output;
            }
        }
     Console.WriteLine(src);

•

Join Date: Feb 2009

Posts: 3,442

Reputation: sknake has much to be proud of

Solved Threads: 624

sknake

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.NET Enthusiast

Re: Using StreamReader with sockets for the 2nd time

Jul 31st, 2009

fulcrum -- You may also consider using HttpWebRequest to simplify what you are trying to accomplish. I realize this isn't what you asked but I thought I would mention it in case you haven't seen it before.

 Help with Code Tags 
 c# Syntax (Toggle Plain Text) 
    private static void GetPage(string URL, string Referrer)
    {
      HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(URL);
      req.Method = "GET";
      req.Referer = Referrer;
      //req.Headers.Add
 
      HttpWebResponse objResponse = (HttpWebResponse)req.GetResponse();
      using (StreamReader sr = new StreamReader(objResponse.GetResponseStream()))
      {
        string htmlStuff = sr.ReadToEnd();
        sr.Close();
      }
    }
    private static void GetPage(string URL, string Referrer)
    {
      HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(URL);
      req.Method = "GET";
      req.Referer = Referrer;
      //req.Headers.Add

      HttpWebResponse objResponse = (HttpWebResponse)req.GetResponse();
      using (StreamReader sr = new StreamReader(objResponse.GetResponseStream()))
      {
        string htmlStuff = sr.ReadToEnd();
        sr.Close();
      }
    }

Scott Knake
Custom Software Development
Apex Software, Inc.

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Join Date: Jul 2009

Posts: 3

Reputation: fulcrum9 is an unknown quantity at this point

Solved Threads: 0

fulcrum9

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Newbie Poster

Re: Using StreamReader with sockets for the 2nd time

Jul 31st, 2009

@adatapost: If you only want to send&read data once, the code is fine. Otherwise not. That's the problem here.

@sknake: I know I can use HttpWebRequest, but I wanted to use sockets because then I'd already know how to use sockets. And I already knew how to build GET request.

But I might try it out if we can't find a solution for the socket read problem.

@DangerDev: You gave me the best answer so far. Thx

I'll search on google about that seek function. Maybe somebody else found a solution for it.

Thanks everybody for the replies so far. I appreciate the help.

Last edited by fulcrum9; Jul 31st, 2009 at 12:56 pm.