C#, tcpClient to Multiple IP Address but on the same port

Question

Scenario:

I have multiple machines, each wit hit's own IP, that run a tcpServer, all on the same port. During each transaction data is sent if the tcpServer port is opened. It, looks for a client before opening the port.

What I Need:

I'm writing an app, that needs to: 1. Check through the list of IP's if they are availible 2. Open a tcpClient port to each machine IP, (all on the same ports) 3. After every specified time make sure the connection is open, if not reopen connection.

Future:

I use an XMl file to give the SQL data which is used to get the list of machines and the port to listen on. In this xml is a udp setting as well, if this is yes, then the data being sent, must be received and redirected to a specified UDP port.

The Class:

 public static void tcpListen(IPAddress server, int port)
        {
            try
            {
                TcpListener listener = new TcpListener(server, port);
                listener.AcceptTcpClient();
                listener.Start();

                while (true)
                {
                    Socket client = listener.AcceptSocket();

                    var childSocketThread = new Thread(() =>
                    {
                        byte[] data = new byte[100];
                        int size = client.Receive(data);
                        for (int i = 0; i < size; i++)
                        feedback = server + ":" + port + ": " + Convert.ToChar(data[i]);

                        using (StreamWriter w = File.AppendText("TCPLog.log"))
                        {
                            Log(feedback, w);
                        }
                        client.Close();
                    });
                    childSocketThread.Start();
                }
            }
            catch (Exception err)
            {
                using (StreamWriter w = File.AppendText("error.log"))
                {
                    Log("tcpControl.tcpListen: " + err.Message, w);
                }
            }
        }

The part of the code that repeats every few seconds:

private void ptoCheck()
        {
            IPAddress sourceIP;
            int sourcePort;
            int destinationPort;
            string tcpStatus;
            int oldCOunt = dgvWorkstations.RowCount;
            int newCount = sqlScripts.posCount(sqlServer, sqlUser, sqlPassword, sqlDatabase);

            if (newCount != oldCOunt)
            {
                getWorkstations();
            }

            try
            {
                foreach (DataGridViewRow row in dgvWorkstations.Rows)
                {
                    int i = row.Index;
                    bool tcpState;
                    dgvWorkstations["Status", i].Value = "Checking";
                    dgvWorkstations.Refresh();
                    name = row.Cells["POS_Name"].Value.ToString();
                    sourceIP = IPAddress.Parse(row.Cells["LastKnownIP"].Value.ToString());
                    sourcePort = Convert.ToInt32(row.Cells["Receive_Port"].Value.ToString());
                    destinationPort = Convert.ToInt32(row.Cells["Send_Port"].Value.ToString());
                    tcpState = tcpControl.tcpCheck(sourceIP, sourcePort, name);

                    if (tcpState == false)
                    {
                        dgvWorkstations["Status", i].Value = "Connecting";                        
                        dgvWorkstations.Refresh();
                        tcpStatus = tcpControl.tcpConnect(sourceIP, sourcePort, name);
                        tcpControl.tcpListen(sourceIP, sourcePort);
                        dgvWorkstations["Status", i].Value = tcpStatus;
                    }

                    if (tcpState == true)
                    {
                        dgvWorkstations["Status", i].Value = "Connected";
                        dgvWorkstations.Refresh();
                    }
                    i = i + 1;
                }
            }
            catch (Exception err)
            {
                using (StreamWriter w = File.AppendText("AError.log"))
                {
                    Log("frmMain.ptoCheck: (" + name + ") " + err.Message, w);
                }
            }//End Catch
        }

Answer 1

I got the following code toe work, from my class I can now make multiple connections, however. The part where I call another method to listen and receive the data blocks the first method and holds it untill the connection drops without making further connections.

My Class:

public void tcpTest2(IPAddress server, Int32 port, int x)
        {
            TcpClient client;

            sendData("Connecting to Host: " + server + " on port: " + port.ToString() + "...");
            sendStatus("Connecting", x);

            try
            {
                client = new TcpClient(server.ToString(), port); 

                if (false)
                {

                }               

                if (true)
                {
                    sendData("Connection to Host: " + server + " on port: " + port.ToString() + "..ESTABLISHED");
                    sendStatus("Connected", x);        
                    receiveData(client, server, port);
                }

            }
            catch (Exception)
            {
                sendData("Connection to Host: " + server + " on port: " + port.ToString() + "..FAILED");
                sendStatus("Failed", x);
            }
        }

        public void receiveData(TcpClient client, IPAddress server, int port)
        {
            Byte[] data = System.Text.Encoding.Default.GetBytes("|");
            data = new byte[1024];
            string stringData;
            bool connected;
            connected = true;

            while (connected == true)
            {
                string fromC = client.Client.RemoteEndPoint.ToString();
                NetworkStream ns = client.GetStream();
                int recv = ns.Read(data, 0, data.Length);
                stringData = Encoding.ASCII.GetString(data, 0, recv);
                sendUpdate("{" + fromC + "}" + stringData);
                connected = IsConnected(client);
            }

            if (connected == false)
            {
                sendData("Connection to Host: " + server + " on port: " + port.ToString() + "..LOST");
                sendLost(server);
            }
        }

        public bool IsConnected(TcpClient client)
        {
            try
            {
                if (client != null && client.Client != null && client.Client.Connected)
                {
                    if (client.Client.Poll(0, SelectMode.SelectRead))
                    {
                        byte[] buff = new byte[1];
                        if (client.Client.Receive(buff, SocketFlags.Peek) == 0)
                        {
                            return false;
                        }
                        else
                        {
                            return true;
                        }
                    }

                    return true;
                }
                else
                {
                    return false;
                }
            }
            catch
            {
                return false;
            }
        }
    }