Client auto exit when connect with server

[haanjae]

i had been trying out the client server program. the client exit or crash by itself when connection establish with server. this error code 10045 being use inside the server code as the socket exception, but why the client still exit automatically?
Please help me, thanks you.

catch (ObjectDisposedException)
            {
                System.Diagnostics.Debugger.Log(0, "1", "\nOnDataReceived: Socket has been closed\n");
            }
            catch (SocketException se)
            {
                if (se.ErrorCode == 10054) // Error code 
                {
                    string msg = "User no." + socketData.m_clientNumber + " Disconnected" + "\n";
                    AppendToRichEditControl(msg);
                    m_workerSocketList[socketData.m_clientNumber - 1] = null;
                    UpdateClientListControl();
                }
                else
                {
                    MessageBox.Show(se.Message);
                }
            }

[Aimee Bailey]

If you have a look at the message that comes along with the error code, you'll see it says "An existing connection was forcibly closed by the remote host", which means the server closed the connection. As the socket or TCP classes don't have events to tell you when a connection was dropped, this is usually the message you should handle to tell the user that the server disconnected unexpectedly.

Hope this helps.

Aimee.

[haanjae]

thx for reply me....
I try to debug again, i think this is the code that cause the Client program exit by itself, under public void WaitForData()

m_result = m_clientSocket.BeginReceive(theSocPkt.dataBuffer, 0, theSocPkt.dataBuffer.Length, SocketFlags.None, m_pfnCallBack, theSocPkt);
 

but i dont know how to fixed it, because that code also exist in the server program. not sure which side is causing the error.
Please help, thanks a lot.

below is the full client code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.Threading;
namespace AsynClient
{
    public partial class Clientsoc : Form
    {
        byte[] m_dataBuffer = new byte[10];
        IAsyncResult m_result;
        public AsyncCallback m_pfnCallBack;
 
        public Socket m_clientSocket;
        public Clientsoc()
        {
            InitializeComponent();
 
            txtbxipadd.Text = GetIP();
        }
 
        void btnexit_Click(object sender, System.EventArgs e)
        {
            if (m_clientSocket != null)
            {
                m_clientSocket.Close();
                m_clientSocket = null;
            }
            Close();
        }
 
       void btnconnect_Click(object sender, System.EventArgs e)
        {
            // See if we have text on the IP and Port text fields
            if (txtbxipadd.Text == "" || txtbxport.Text == "")
            {
                MessageBox.Show("IP Address and Port Number are required to connect to the Server\n");
                return;
            }
            try
            {
                UpdateControls(false);
                // Create the socket instance
                m_clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
 
                // Cet the remote IP address
                IPAddress ip = IPAddress.Parse(txtbxipadd.Text);
                int iPortNo = System.Convert.ToInt16(txtbxport.Text);
                // Create the end point 
                IPEndPoint ipEnd = new IPEndPoint(ip, iPortNo);
                // Connect to the remote host
                m_clientSocket.Connect(ipEnd);
                if (m_clientSocket.Connected)
                {
                    UpdateControls(true);
                    //Wait for data asynchronously 
                    WaitForData();
                }
            }
            catch (Exception se)
            {
                string str;
                str = "\nConnection failed, is the server running?\n" + se.Message;
                MessageBox.Show(str);
                UpdateControls(false);
            }
        }
        void ButtonSendMessageClick(object sender, System.EventArgs e)
        {
            try
            {
                string msg = richtxtbxmsg.Text;
                // New code to send strings
                NetworkStream networkStream = new NetworkStream(m_clientSocket);
                System.IO.StreamWriter streamWriter = new System.IO.StreamWriter(networkStream);
                streamWriter.WriteLine(msg);
                streamWriter.Flush();
 
                /* Use the following code to send bytes
                byte[] byData = System.Text.Encoding.ASCII.GetBytes(objData.ToString ());
                if(m_clientSocket != null){
                    m_clientSocket.Send (byData);
                }
                */
            }
            catch (SocketException se)
            {
                MessageBox.Show(se.Message);
            }    
        }
        public void WaitForData()
        {
            try
            {
                if (m_pfnCallBack == null)
                {
                    m_pfnCallBack = new AsyncCallback(OnDataReceived);
                }
                SocketPacket theSocPkt = new SocketPacket();
                theSocPkt.thisSocket = m_clientSocket;
                // Start listening to the data asynchronously
               m_result = m_clientSocket.BeginReceive(theSocPkt.dataBuffer, 0,theSocPkt.dataBuffer.Length, SocketFlags.None, m_pfnCallBack, theSocPkt); //causing exit
 
            }
            catch (Exception se)
            {
                MessageBox.Show(se.Message);
            }
        }
 
        public class SocketPacket
        {
            public System.Net.Sockets.Socket thisSocket;
            public byte[] dataBuffer = new byte[1024];
        }
 
        public void OnDataReceived(IAsyncResult asyn)
        {
            try
            {
                SocketPacket theSockId = (SocketPacket)asyn.AsyncState;
                int iRx = theSockId.thisSocket.EndReceive(asyn);
                char[] chars = new char[iRx + 1];
                System.Text.Decoder d = System.Text.Encoding.UTF8.GetDecoder();
                int charLen = d.GetChars(theSockId.dataBuffer, 0, iRx, chars, 0);
                System.String szData = new System.String(chars);
                richtxtbxstatuslog.Text = richtxtbxstatuslog.Text + szData;
                WaitForData();
            }
            catch (ObjectDisposedException)
            {
                System.Diagnostics.Debugger.Log(0, "1", "\nOnDataReceived: Socket has been closed\n");
            }
            catch (SocketException se)
            {
                MessageBox.Show(se.Message);
            }
        }
        private void UpdateControls(bool connected)
        {
            btnconnect.Enabled = !connected;
            btndisconnect.Enabled = connected;
            string connectStatus = connected ? "Connected" : "Not Connected";
            richtxtbxstatuslog.Text = connectStatus;
        }
 
        void btndisconnect_Click(object sender, EventArgs e)
        {
            if (m_clientSocket != null)
            {
                m_clientSocket.Close();
                m_clientSocket = null;
                UpdateControls(false);
            }
        }
        String GetIP()
        {
            String strHostName = Dns.GetHostName();
 
            // Find host by name
            IPHostEntry iphostentry = Dns.GetHostByName(strHostName);
 
            // Grab the first IP addresses
            String IPStr = "";
            foreach (IPAddress ipaddress in iphostentry.AddressList)
            {
                IPStr = ipaddress.ToString();
                return IPStr;
            }
            return IPStr;
        }
        private void btnclear_Click(object sender, System.EventArgs e)
        {
            richtxtbxstatuslog.Clear();
        }
    }
}