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C# Winforms using TcpListener I can't connect to server from other devices on my LAN

I have a Winforms application that's going to transfers data to an Android application, for now it accepts a connection and displays a line of text as output. I tested on my local machine using the telnet command in PowerShell and it returns the correct message. When I tried the command from another PC on my network, it just times out and fails to connect. I made sure the port was free and that my firewall was turned off.
Here is my method:
public void senddata()
{
new Thread(() =>
{
Thread.CurrentThread.IsBackground = true;
TcpListener server = null;
try
{
Int32 port = 4296;
IPAddress localAddr =IPAddress.Any;
server = new TcpListener(localAddr, port);
server.Start();
Byte[] bytes = new Byte[256];
while (true)
{
server.Start();
Debug.WriteLine("Waiting for a connection... ");
TcpClient client = server.AcceptTcpClient();
NetworkStream stream = client.GetStream();
Debug.WriteLine("Connected!");
server.Stop();
while (stream.Read(bytes, 0, bytes.Length) != 0)
{
string data = "CPU: " + cpuCircle.Value + " C" + " | GPU: " + gpuCircle.Value + " C";
byte[] msg = System.Text.Encoding.ASCII.GetBytes(data);
stream.Write(msg, 0, msg.Length);
stream.Flush();
}
client.Close();
}
}
catch (SocketException m)
{
Debug.WriteLine("SocketException: "+m);
}
finally
{
server.Stop();
}
}).Start();
}
Any idea what I'm doing wrong?

I think the main issue is that your listener object is being created in Thread itself due to which only first client able to connect. Please make TcpListener object before calling senddata() method and this listener should accept connection before calling senddata() method as well and pass client object to senddata(TcpClient client) method. By doing so you would be able to entertain theoretically unlimited clients simultanously:
Try This:
void StackOverflow4() // Your calling method
{
TcpListener server = null;
Int32 port = 4296;
IPAddress localAddr = IPAddress.Any;
try
{
server = new TcpListener(localAddr, port);
server.Start();
Byte[] bytes = new Byte[256];
while (true)
{
Debug.WriteLine("Waiting for a connection... ");
TcpClient client = server.AcceptTcpClient();
senddata(client);
}
}
catch (SocketException m)
{
Debug.WriteLine("SocketException: " + m);
//Some logic to restart listner
}
catch(Exception ex)
{
Debug.WriteLine(ex.Message);
//Some logic to restart listner
}
}
public void senddata(TcpClient client)
{
new Thread(() =>
{
Thread.CurrentThread.IsBackground = true;
try
{
Byte[] bytes = new Byte[256];
while (true)
{
NetworkStream stream = client.GetStream();
Debug.WriteLine("Connected!");
//server.Stop();
while (stream.Read(bytes, 0, bytes.Length) != 0)
{
string data = "CPU: " + cpuCircle.Value + " C" + " | GPU: " + gpuCircle.Value + " C";
byte[] msg = System.Text.Encoding.ASCII.GetBytes(data);
stream.Write(msg, 0, msg.Length);
stream.Flush();
}
client.Close();
}
}
catch (SocketException m)
{
Debug.WriteLine("SocketException: " + m);
}
finally
{
//server.Stop();
}
}).Start();
}

C# socket client server messages swap

I have setup a client server chat system. That will have to work on different computers. At the moment I am testing and so both client and server are on my localhost.
At the moment I focus on the client reception (with a 8192 byte buffer) for it is that the problem resides.
And the problem is that when issue a command with very short text (here 123):
Server SHORT_COMMAND 123% ---> Client SHORT_COMMAND 123%
but when I issue a very long command (24k) each single batch does not arrive in the correct order
E.g. imagine a very long text 111.....11112222....2222333....33334444....4444
LONG_COMMAND 111....3333% is therefore automatically cut into
LONG_COMMAND 111....1111
2222....2222
3333...3333
4444...4444%
and sent in that order
what is wrong is the reception and what might happen is to receive
LONG_COMMAND 111....1111
2222....2222
4444...4444%
3333...3333
or it might get mixed with other short commands like
LONG_COMMAND 111....1111
2222....2222
SHORT_COMMAND 123%
3333...3333
4444...4444%
Take into account that some messages can be sent very quickly one after the other.
Thank you for ANY help
Patrick
Client code
I start the client with the following routine. In my case I pass -1
public static bool StartClient(string strIpAddress, string strPort)
{
// Connect to a remote device.
try
{
if (strIpAddress.Trim() == "-1")
strIpAddress = GetLocalIPAddress();
IPAddress ipAddress = IPAddress.Parse(strIpAddress);
int port = int.Parse(strPort);
IPEndPoint remoteEP = new IPEndPoint(ipAddress, port);
socketClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
socketClient.BeginConnect(remoteEP, new AsyncCallback(ConnectClientCallback), socketClient);
OnNotification_Client?.Invoke(eSocketOperation.CONNECT, "Client connected to " + strIpAddress + " port=" + strPort, eSocketOperationResultType.SUCCESS);
ReceiveClient();
return true;
}
catch (Exception e)
{
MessageBox.Show("StartClient exc:" + e.ToString());
return false;
}
}
then
private static void ConnectClientCallback(IAsyncResult ar)
{
try
{
socketClient = (Socket)ar.AsyncState;
socketClient.EndConnect(ar);
}
catch (Exception e)
{
MessageBox.Show(e.ToString());
}
}
The following part is the reception with:
public static void ReceiveClient()
{
try
{
StateObject state = new StateObject();
state.workSocket = socketClient;
socketClient.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReceiveCallback_Client), state);
}
catch (Exception e)
{
MessageBox.Show(e.ToString(), "ReceiveClient", MessageBoxButton.OK, MessageBoxImage.Error);
}
}
finally
private static void ReceiveCallback_Client(IAsyncResult ar)
{
try
{
StateObject state = (StateObject)ar.AsyncState;
Socket client = state.workSocket;
if (!client.Connected)
return;
int bytesRead = client.EndReceive(ar);
if (bytesRead > 0)
{
string message = Encoding.ASCII.GetString(state.buffer, 0, bytesRead);
if (message == null)
OnNotification_Client?.Invoke(eSocketOperationResultType.ERROR, "Received null message from server", eSocketOperationResultType.ERROR);
else
{
strReceivedMessageClient += message;
if (strReceivedMessageClient.EndsWith(StateObject.CONFIRMATION.ToString()))
{
...
Server Code
The server is started with
public static void StartServer(string _strPort)
{
Serializers.Logger.WriteLog("StartServer");
StrPort = _strPort;
// Data buffer for incoming data.
byte[] bytes = new Byte[BufferSize];
IPAddress ipAddress = IPAddress.Parse(GetLocalIPAddress());
int port = int.Parse(_strPort);
IPEndPoint localEndPoint = new IPEndPoint(ipAddress, port);
if (listener == null)
listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
try
{
listener.Bind(localEndPoint);
listener.Listen(100);
OnNotification_Server?.Invoke("Waiting for a connection on " + ipAddress.ToString());
listener.BeginAccept(new AsyncCallback(AcceptCallbackServer), listener);
}
catch (Exception e)
{
MessageBox.Show(e.ToString());
}
}
Accept
public static void AcceptCallbackServer(IAsyncResult ar)
{
if (listener == null)
return;
listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
StateObject state = new StateObject();
state.workSocket = handler;
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReceiveCallback_Server), state);
}
and last but not least the send:
public static void SendFromServerToClient(object command, String data, eSocketOperationResultType sort)
{
string strMessage; ;
strMessage = command.ToString() + '|' + data + '|' + sort + "%";
byte[] byteData = Encoding.ASCII.GetBytes(strMessage);
try
{
if (socketServer != null)
socketServer.BeginSend(byteData, 0, byteData.Length, 0, new AsyncCallback(SendCallback), socketServer);
}
catch (Exception exc)
{
}
}
private static void SendCallback(IAsyncResult ar)
{
try
{
Socket handler = (Socket)ar.AsyncState;
int bytesSent = handler.EndSend(ar);
}
catch (Exception e)
{
MessageBox.Show(e.ToString());
}
}

C# TCP Server combining received data

I'm working on a rough TCP Server/Client. It works like this:
Client sends message to server > Server sends all user data to each client. I have this in a loop as I'm going to use this transfer of data for multiplayer in a game. However, for some reason my server will combine incoming data into one string instead of reading it line by line. For example, it should read something like
john:0|0
for user data, but instead it reads like john:0|0john:0|0john:0|0john:0|0
I've tried setting a delay on sending and receiving, but it only seems to work if I delay more than 100ms.
Server
class Program
{
private static Socket _serverSocket;
private static readonly List<Socket> _clientSockets = new List<Socket>();
private const int _BUFFER_SIZE = 2048;
private const int _PORT = 100;
private static readonly byte[] _buffer = new byte[_BUFFER_SIZE];
public static bool clientConnected = false;
public static Socket current;
public static int delay = 100; //65
public static string username = "";
public static int dataSent = 0;
public static int dataReceived = 0;
public static List<Player> players = new List<Player>();
static void Main()
{
Console.Title = "Server";
SetupServer();
Console.ReadLine(); // When we press enter close everything
CloseAllSockets();
}
private static void SetupServer()
{
Console.WriteLine("Setting up server...");
_serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
_serverSocket.Bind(new IPEndPoint(IPAddress.Any, _PORT));
_serverSocket.Listen(5);
_serverSocket.BeginAccept(AcceptCallback, null);
Console.WriteLine("Server setup complete");
Console.WriteLine("Listening on port: " + _PORT);
}
private static void CloseAllSockets()
{
foreach (Socket socket in _clientSockets)
{
socket.Shutdown(SocketShutdown.Both);
socket.Close();
}
_serverSocket.Close();
}
private static void AcceptCallback(IAsyncResult AR)
{
Socket socket;
try
{
socket = _serverSocket.EndAccept(AR);
}
catch (ObjectDisposedException) // I cannot seem to avoid this (on exit when properly closing sockets)
{
return;
}
_clientSockets.Add(socket);
socket.BeginReceive(_buffer, 0, _BUFFER_SIZE, SocketFlags.None, ReceiveCallback, socket);
Console.WriteLine("Client connected: " + socket.RemoteEndPoint);
_serverSocket.BeginAccept(AcceptCallback, null);
clientConnected = true;
}
private static void ReceiveCallback(IAsyncResult AR)
{
current = (Socket)AR.AsyncState;
int received = 0;
try
{
received = current.EndReceive(AR);
}
catch (SocketException)
{
Console.WriteLine("Client forcefully disconnected");
current.Close(); // Dont shutdown because the socket may be disposed and its disconnected anyway
_clientSockets.Remove(current);
return;
}
byte[] recBuf = new byte[received];
Array.Copy(_buffer, recBuf, received);
string text = Encoding.ASCII.GetString(recBuf);
if (text.Contains("newuser:"))
{
string newuser = text.Replace("newuser:", "");
Player newPlayer = new Player(newuser, current.RemoteEndPoint.ToString());
players.Add(newPlayer);
SendString("newuser:" + newuser);
Console.WriteLine(newuser + " has joined the game.");
}
else
{
Console.WriteLine(text); //This is where the client text gets mashed together
}
current.BeginReceive(_buffer, 0, _BUFFER_SIZE, SocketFlags.None, ReceiveCallback, current);
}
public static void SendString(string message)
{
try
{
byte[] data = Encoding.ASCII.GetBytes(message.ToString());
current.Send(data);
//current.BeginReceive(_buffer, 0, _BUFFER_SIZE, SocketFlags.None, ReceiveCallback, current);
dataSent++;
}
catch (Exception ex)
{
Console.WriteLine("Client disconnected!" + ex.Message);
}
Console.WriteLine(dataSent);
}
}
Client.cs
public static class Client
{
public static string Username = "null";
public static int delay = 85;
public static bool hasLoggedin = false;
public static int dataSent = 0;
private static readonly Socket _clientSocket = new Socket
(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
private const int port = 100;
public static void Init()
{
Console.Title = "Client";
ConnectToServer();
Exit();
}
private static void ConnectToServer()
{
int attempts = 0;
while (!_clientSocket.Connected)
{
try
{
attempts++;
Console.Write("Username: ");
//Username = Console.ReadLine();
Username = "Matt";
LocalPlayer.username = Username;
Console.Write("IP: ");
string ip = "192.168.0.2";
Console.WriteLine("Port[default]: " + port);
Console.WriteLine("Connection attempt to " + ip + ": " + attempts + " attempts");
IPAddress ipAd = IPAddress.Parse(ip);
_clientSocket.Connect(ipAd, port);
}
catch (SocketException e)
{
Console.Clear();
Console.WriteLine(e.Message);
Console.ReadLine();
}
}
Console.WriteLine("Connected!");
SendLoginPacket();
}
public static void SendLoginPacket()
{
if (hasLoggedin == false)
{
SendString("newuser:" + Username);
Thread.Sleep(delay);
hasLoggedin = true;
}
RequestLoop();
}
private static void RequestLoop()
{
while (true)
{
//SendData();
ReceiveResponse();
}
}
private static void Exit()
{
_clientSocket.Shutdown(SocketShutdown.Both);
_clientSocket.Close();
Environment.Exit(0);
}
public static void SendData()
{
string data = LocalPlayer.username + ":" + LocalPlayer.velocity.X + "|" + LocalPlayer.velocity.Y;
SendString(data);
}
private static void SendString(string text)
{
byte[] buffer = Encoding.ASCII.GetBytes(text);
Console.WriteLine("Sent: " + text);
_clientSocket.Send(buffer, 0, buffer.Length, SocketFlags.None);
dataSent++;
Thread.Sleep(delay);
Console.WriteLine(dataSent);
}
private static void ReceiveResponse()
{
var buffer = new byte[2048];
int received = _clientSocket.Receive(buffer, SocketFlags.None);
if (received == 0) return;
var data = new byte[received];
Array.Copy(buffer, data, received);
string text = Encoding.ASCII.GetString(data);
if (text.Contains("newuser:"))
{
string str = text.Replace("newuser:", "");
if (!(str == LocalPlayer.username))
{
Player player = new Player(str, Globals.Content);
Globals.players.Add(player);
Console.WriteLine(str + " has joined the game.");
}
}
Console.WriteLine("Clients connected: " + Globals.players.Count());
}
}
How can I change the server so it reads incoming data one at a time, instead of mashing it into one big string?
EDIT: Note the LocalPlayer class is sending it's movement position using the Client class.

This is because the TCP/IP protocol provides the stream of the data (bytes). If the strings are not separated explicitly, they are "concatenated" because of "streaming".
It is required to "join" the messages using the "separator" when sending and "split" the messages using the "separator" when receiving. One of the following alternatives could be considered to implement the "separator" concept:
Introduce the "end-of-the-message" marker.
Introduce the message header which contains the length of the message.
The small article, TCP/IP client-server application: exchange with string messages, may be useful to understand the mentioned alternatives.
Update
I would like to recommend implementing the "messaging" appropriately.
Although it seems there is no the reason to compare the source code because it of its principal flaw (lack of "messaging" mechanism), the source code I have used to test the Client and the Server is attached.
Client
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
internal sealed class Program
{
private const int Port = 100;
private readonly Socket clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
private bool hasLoggedin;
private int dataSent;
public static void Main()
{
var client = new Program();
client.ConnectToServer();
client.Exit();
}
private void ConnectToServer()
{
int attempts = 0;
while (!clientSocket.Connected)
{
try
{
attempts++;
string ip = "127.0.0.1";
Console.WriteLine("Port[default]: " + Port);
Console.WriteLine("Connection attempt to " + ip + ": " + attempts + " attempts");
var address = IPAddress.Parse(ip);
clientSocket.Connect(address, Port);
}
catch (SocketException e)
{
Console.Clear();
Console.WriteLine(e.Message);
Console.ReadLine();
}
}
Console.WriteLine("Connected!");
SendLoginPacket();
}
private void SendLoginPacket()
{
if (hasLoggedin == false)
{
SendString("newuser:" + Guid.NewGuid());
hasLoggedin = true;
}
RequestLoop();
}
private void RequestLoop()
{
while (true)
{
SendData();
ReceiveResponse();
}
}
private void Exit()
{
clientSocket.Shutdown(SocketShutdown.Both);
clientSocket.Close();
}
private void SendData()
{
const string Data = "username:100|200";
SendString(Data);
}
private void SendString(string text)
{
byte[] buffer = Encoding.ASCII.GetBytes(text);
Console.WriteLine("Sent: " + text);
clientSocket.Send(buffer, 0, buffer.Length, SocketFlags.None);
dataSent++;
Console.WriteLine(dataSent);
}
private void ReceiveResponse()
{
var buffer = new byte[2048];
int received = clientSocket.Receive(buffer, SocketFlags.None);
if (received == 0)
{
return;
}
var data = new byte[received];
Array.Copy(buffer, data, received);
string text = Encoding.ASCII.GetString(data);
if (text.Contains("newuser:"))
{
string str = text.Replace("newuser:", string.Empty);
Console.WriteLine(str + " has joined the game.");
}
Console.WriteLine("Clients connected.");
}
}
Server
using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Sockets;
using System.Text;
internal sealed class Program
{
private const int BufferSize = 2048;
private const int Port = 100;
private readonly List<Socket> clientSockets = new List<Socket>();
private readonly byte[] buffer = new byte[BufferSize];
private readonly List<Player> players = new List<Player>();
private Socket serverSocket;
private Socket current;
private int dataSent;
public static void Main()
{
var program = new Program();
program.SetupServer();
Console.ReadLine();
program.CloseAllSockets();
}
private void SetupServer()
{
Console.WriteLine("Setting up server...");
serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
serverSocket.Bind(new IPEndPoint(IPAddress.Any, Port));
serverSocket.Listen(5);
serverSocket.BeginAccept(AcceptCallback, null);
Console.WriteLine("Server setup complete");
Console.WriteLine("Listening on port: " + Port);
}
private void CloseAllSockets()
{
foreach (Socket socket in clientSockets)
{
socket.Shutdown(SocketShutdown.Both);
socket.Close();
}
serverSocket.Close();
}
private void AcceptCallback(IAsyncResult AR)
{
Socket socket;
try
{
socket = serverSocket.EndAccept(AR);
}
catch (ObjectDisposedException) // I cannot seem to avoid this (on exit when properly closing sockets)
{
return;
}
clientSockets.Add(socket);
socket.BeginReceive(buffer, 0, BufferSize, SocketFlags.None, ReceiveCallback, socket);
Console.WriteLine("Client connected: " + socket.RemoteEndPoint);
serverSocket.BeginAccept(AcceptCallback, null);
}
private void ReceiveCallback(IAsyncResult AR)
{
current = (Socket)AR.AsyncState;
int received = 0;
try
{
received = current.EndReceive(AR);
}
catch (SocketException)
{
Console.WriteLine("Client forcefully disconnected");
current.Close(); // Dont shutdown because the socket may be disposed and its disconnected anyway
clientSockets.Remove(current);
return;
}
byte[] recBuf = new byte[received];
Array.Copy(buffer, recBuf, received);
string text = Encoding.ASCII.GetString(recBuf);
if (text.Contains("newuser:"))
{
string newuser = text.Replace("newuser:", string.Empty);
Player newPlayer = new Player(newuser, current.RemoteEndPoint.ToString());
players.Add(newPlayer);
SendString("newuser:" + newuser);
Console.WriteLine(newuser + " has joined the game.");
}
else
{
// This is where the client text gets mashed together.
Console.WriteLine(text);
}
current.BeginReceive(buffer, 0, BufferSize, SocketFlags.None, ReceiveCallback, current);
}
private void SendString(string message)
{
try
{
byte[] data = Encoding.ASCII.GetBytes(message.ToString());
current.Send(data);
// current.BeginReceive(buffer, 0, BufferSize, SocketFlags.None, ReceiveCallback, current);
dataSent++;
}
catch (Exception ex)
{
Console.WriteLine("Client disconnected!" + ex.Message);
}
Console.WriteLine(dataSent);
}
}
internal sealed class Player
{
public Player(string newuser, string toString)
{
}
}
Client output
Port[default]: 100
Connection attempt to 127.0.0.1: 1 attempts
Connected!
Sent: newuser:6b06f0a6-bdb0-4471-ac58-fa9c490b7555
1
Sent: username:100|200
2
6b06f0a6-bdb0-4471-ac58-fa9c490b7555username:100|200 has joined the game.
Clients connected.
Sent: username:100|200
3
Server output
Setting up server...
Server setup complete
Listening on port: 100
Client connected: 127.0.0.1:1082
1
6b06f0a6-bdb0-4471-ac58-fa9c490b7555username:100|200 has joined the game.
username:100|200

Send objects over TCP with multiple clients and one server

Okay, I've been looking around and have found tutorials on both sending custom objects over TCP and also connecting multiple clients to one server, however I haven't been able to find an example of both so have decided to try it myself however I'm stuck. I so far have written a server that can handle an unlimited number of clients but have failed to implement sending of objects. This is the code I have so far for sending custom objects:
Client code:
Person p = new Person("Tyler", "Durden", 30); // create my serializable object
string serverIp = "127.0.0.1";
TcpClient client = new TcpClient(serverIp, 9050); // have my connection established with a Tcp Server
IFormatter formatter = new BinaryFormatter(); // the formatter that will serialize my object on my stream
NetworkStream strm = client.GetStream(); // the stream
formatter.Serialize(strm, p); // the serialization process
strm.Close();
client.Close();
Server code:
TcpListener server = new TcpListener(9050);
server.Start();
TcpClient client = server.AcceptTcpClient();
NetworkStream strm = client.GetStream();
IFormatter formatter = new BinaryFormatter();
Person p = (Person)formatter.Deserialize(strm); // you have to cast the deserialized object
strm.Close();
client.Close();
server.Stop();
This is the code I currently have for multiple clients:
Server code:
private ArrayList m_aryClients = new ArrayList(); //List of connected clients (Used for threading)
public Program()
{
//Empty constructor
}
static Program()
{
}
#region Main Enty Point
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
//Set log file location
setLogFileLocation("/usr/local/bin/ClipCloud/" + DateTime.Now.ToShortDateString() + ".log");
//Start the application
printAndLog("Starting server");
Program appmain = new Program();
//Get local hostname
IPAddress[] addressList = null;
string hostName = "";
try
{
hostName = Dns.GetHostName();
addressList = Dns.GetHostByName(hostName).AddressList;
}
catch (Exception ex)
{
printAndLog("Failed to get local address (" + ex.Message + ")", 1);
}
//Start listening and set up threads
if ((addressList == null ? false : (int)addressList.Length >= 1))
{
object[] objArray = new object[] { "Listening on : (", hostName, ") ", addressList[0], ",", 399 };
printAndLog(string.Concat(objArray), 0);
Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
socket.Bind(new IPEndPoint(addressList[0], 399));
socket.Listen(10);
socket.BeginAccept(new AsyncCallback(appmain.OnConnectRequest), socket);
//Wait until user types exit
while (!(Console.ReadLine().ToLower() == "exit"))
{}
printAndLog("Shutting down server");
socket.Close();
//Clean up after yourself
GC.Collect();
GC.WaitForPendingFinalizers();
printAndLog("Application successfully shutdown");
}
else
{
printAndLog("Unable to obtain local address" , 2);
}
}
#endregion
#region Server requests
public void NewConnection(Socket sockClient)
{
//new client connected
ClientHandler clientHandler = new ClientHandler(sockClient);
m_aryClients.Add(clientHandler);
printAndLog(string.Concat("Client (",clientHandler.Sock.RemoteEndPoint, ") connected"));
//Send client welcome message
DateTime now = DateTime.Now;
string str = string.Concat("{", now.ToString("G"), "}");
byte[] bytes = Encoding.ASCII.GetBytes(str.ToCharArray());
clientHandler.Sock.Send(bytes, (int)bytes.Length, SocketFlags.None);
clientHandler.SetupRecieveCallback(this);
}
public void OnConnectRequest(IAsyncResult ar)
{
try
{
Socket asyncState = (Socket)ar.AsyncState;
NewConnection(asyncState.EndAccept(ar));
asyncState.BeginAccept(new AsyncCallback(OnConnectRequest), asyncState);
}
catch (Exception ex)
{
printAndLog(ex.Message);
}
}
public void OnRecievedData(IAsyncResult ar)
{
ClientHandler asyncState = (ClientHandler)ar.AsyncState;
byte[] recievedData = asyncState.GetRecievedData(ar);
if ((int)recievedData.Length >= 1)
{
foreach (ClientHandler mAryClient in this.m_aryClients)
{
try
{
//This is where all data is sent out to all users!
mAryClient.Sock.Send(recievedData);
}
catch
{
printAndLog(string.Concat("Failed to send data to client (", asyncState.Sock.RemoteEndPoint, ")"), 2);
mAryClient.Sock.Close();
this.m_aryClients.Remove(asyncState);
return;
}
}
asyncState.SetupRecieveCallback(this);
}
else
{
printAndLog(string.Concat("Client (", asyncState.Sock.RemoteEndPoint, ") disconnected"), 0);
asyncState.Sock.Close();
this.m_aryClients.Remove(asyncState);
}
}
#endregion
}
internal class ClientHandler
{
private Socket m_sock;
private byte[] m_byBuff = new byte[50];
public Socket Sock
{
get
{
return this.m_sock;
}
}
public ClientHandler(Socket sock)
{
this.m_sock = sock;
}
public byte[] GetRecievedData(IAsyncResult ar)
{
int num = 0;
try
{
num = this.m_sock.EndReceive(ar);
}
catch
{
}
byte[] numArray = new byte[num];
Array.Copy(this.m_byBuff, numArray, num);
return numArray;
}
public void SetupRecieveCallback(Program app)
{
try
{
AsyncCallback asyncCallback = new AsyncCallback(app.OnRecievedData);
this.m_sock.BeginReceive(this.m_byBuff, 0, (int)this.m_byBuff.Length, SocketFlags.None, asyncCallback, this);
}
catch (Exception ex)
{
Console.WriteLine("Recieve callback setup failed! {0}", ex.Message);
}
}
}
Can someone please help me connecting the two.

Problem with simple tcp\ip client-server

i'm trying to write simple tcp\ip client-server.
here is server code:
internal class Program
{
private const int _localPort = 7777;
private static void Main(string[] args)
{
TcpListener Listener;
Socket ClientSock;
string data;
byte[] cldata = new byte[1024];
Listener = new TcpListener(_localPort);
Listener.Start();
Console.WriteLine("Waiting connections [" + Convert.ToString(_localPort) + "]...");
try
{
ClientSock = Listener.AcceptSocket();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
return;
}
int i = 0;
if (ClientSock.Connected)
{
while (true)
{
try
{
i = ClientSock.Receive(cldata);
}
catch
{
}
try
{
if (i > 0)
{
data = Encoding.ASCII.GetString(cldata).Trim();
ClientSock.Send(cldata);
}
}
catch
{
ClientSock.Close();
Listener.Stop();
Console.WriteLine(
"Server closing. Reason: client offline. Type EXIT to quit the application.");
}
}
}
}
}
And here is client code:
void Main()
{
string data; // Юзерская дата
byte[] remdata ={ };
TcpClient Client = new TcpClient();
string ip = "127.0.0.1";
int port = 7777;
Console.WriteLine("\r\nConnecting to server...");
try
{
Client.Connect(ip, port);
}
catch
{
Console.WriteLine("Cannot connect to remote host!");
return;
}
Console.Write("done\r\nTo end, type 'END'");
Socket Sock = Client.Client;
while (true)
{
Console.Write("\r\n>");
data = Console.ReadLine();
if (data == "END")
break;
Sock.Send(Encoding.ASCII.GetBytes(data));
Sock.Receive(remdata);
Console.Write("\r\n<" + Encoding.ASCII.GetString(remdata));
}
Sock.Close();
Client.Close();
}
When i'm sending to my server i cannt receive data back answer. Sock.Receive(remdata) returns nothing! Why?

You're trying to receive to an empty buffer. You should allocate the buffer with a sensible size, and then take note of the amount of data received:
byte[] buffer = new byte[1024];
...
int bytesReceived = socket.Receive(buffer);
string text = Encoding.ASCII.GetString(buffer, 0, bytesReceived);
(It's somewhat unconventional to use PascalCase for local variables, by the way. I'd also urge you not to just catch Exception blindly, and not to swallow exceptions without logging them.)