Develop Reference

C# using Socket to send message to all client

My objective here to to send a message to the connected clients from my server. The code is working but the only problem is, it can only send message to the client who sent the command. What I need is to received the message by other client. I saw this code in youtube and make a few adjustment. Please find below.
Server Code
class Program
{
private static readonly Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
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];
static void Main(string[] args)
{
Console.Title = "Server";
SetupServer();
Console.ReadLine(); // When we press enter close everything
CloseAllSockets();
}
private static void SetupServer()
{
Console.WriteLine("Setting up server...");
serverSocket.Bind(new IPEndPoint(IPAddress.Any, PORT));
serverSocket.Listen(0);
serverSocket.BeginAccept(AcceptCallback, null);
Console.WriteLine("Server setup complete");
}
/// <summary>
/// Close all connected client (we do not need to shutdown the server socket as its connections
/// are already closed with the clients).
/// </summary>
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 can not 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("{0}", socket.RemoteEndPoint + " connected...");
serverSocket.BeginAccept(AcceptCallback, null);
}
private static void ReceiveCallback(IAsyncResult AR)
{
Socket current = (Socket)AR.AsyncState;
int received;
try
{
received = current.EndReceive(AR);
}
catch (SocketException)
{
Console.WriteLine("Client forcefully disconnected");
// Don't shutdown because the socket may be disposed and its disconnected anyway.
current.Close();
clientSockets.Remove(current);
return;
}
byte[] recBuf = new byte[received];
Array.Copy(buffer, recBuf, received);
string text = Encoding.ASCII.GetString(recBuf);
Console.WriteLine("Received Text: " + text);
if (text.ToLower() == "meeting") // Client requested time
{
foreach (Socket socket in clientSockets)
{
//current = socket;
string message = "meeting";
byte[] data = Encoding.ASCII.GetBytes(message);
socket.Send(data);
//socket.BeginSend(data, 0, data.Length, SocketFlags.None, null, null);
Console.WriteLine("Meeting invite sent to " + socket.RemoteEndPoint);
}
}
else if (text.ToLower() == "exit") // Client wants to exit gracefully
{
// Always Shutdown before closing
Console.WriteLine(current.RemoteEndPoint + " disconnected");
current.Shutdown(SocketShutdown.Both);
current.Close();
clientSockets.Remove(current);
return;
}
else
{
Console.WriteLine("Invalid request");
byte[] data = Encoding.ASCII.GetBytes("Invalid request");
current.Send(data);
Console.WriteLine("Warning Sent");
}
current.BeginReceive(buffer, 0, BUFFER_SIZE, SocketFlags.None, ReceiveCallback, current);
}
}
Client Code
namespace TCP_Client {
public partial class frmTCPClient : Form
{
private readonly Socket ClientSocket = new Socket
(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
private const int PORT = 100;
private byte[] buffer;
private string message { get; set; }
public string serverMessage { get; set; }
public frmTCPClient()
{
InitializeComponent();
}
private void frmTCPClient_Load(object sender, EventArgs e)
{
ConnectToServer();
//UpdateControls();
}
private void UpdateControls()
{
lblMessage.Text = message;
//txtFromServer.Text = serverMessage;
}
private void ConnectToServer()
{
int attempts = 0;
while (!ClientSocket.Connected)
{
try
{
attempts++;
//lblMessage.Text = "Connection attempt " + attempts;
// Change IPAddress.Loopback to a remote IP to connect to a remote host.
//ClientSocket.Connect(IPAddress.Loopback, PORT);
ClientSocket.Connect("172.20.110.129", PORT);
}
catch (SocketException ex)
{
MessageBox.Show(ex.Message + Environment.NewLine + "Connection attempt " + attempts);
}
}
message = "Connected";
}
private void RequestLoop()
{
while (true)
{
SendRequest("");
ReceiveResponse();
}
}
private void SendRequest(string text)
{
string request = text;
SendString(request);
if (request.ToLower() == "exit")
{
Exit();
}
}
/// <summary>
/// Sends a string to the server with ASCII encoding.
/// </summary>
private void SendString(string text)
{
try
{
byte[] buffer = Encoding.ASCII.GetBytes(text);
ClientSocket.Send(buffer, 0, buffer.Length, SocketFlags.None);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
private void button1_Click(object sender, EventArgs e)
{
SendRequest(txtMessage.Text);
ReceiveResponse();
UpdateControls();
}
private void Exit()
{
SendString("exit"); // Tell the server we are exiting
ClientSocket.Shutdown(SocketShutdown.Both);
ClientSocket.Close();
Environment.Exit(0);
}
public void ReceiveResponse()
{
var buffer = new byte[2048];
try
{
if (buffer.ToString().Length == 2048) return;
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);
txtFromServer.Text += text + System.Environment.NewLine;
//MessageBox.Show(text);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
return;
}
}
private void frmTCPClient_FormClosed(object sender, FormClosedEventArgs e)
{
Exit();
}
} }
Update
foreach (object obj in clientSockets)
{
string message = "meeting";
byte[] data = Encoding.ASCII.GetBytes(message);
Socket socket = (Socket)obj;
socket.Send(data);
Console.WriteLine("Meeting invite sent to " + socket.RemoteEndPoint);
}
Image
enter image description here

how to get connectionaborted immediately in Asynchronous Programming?

I was doing Asynchronous Programming in c# when I came across this question,when the network is aborted.
My program can get a exception of ConnectionAborted almost 15 seconds after I send a invaild message from client to server.
My question is if I want to get the exception immediately after the network doesn't work,what need I do.
namespace _10_TCP模块化编程
{
class ObjectState
{
public Socket client;
public MyTcp obj;
public const int BufferSize = 256;
// Receive buffer.
public byte[] buffer = new byte[BufferSize];
// Received data string.
public StringBuilder sb = new StringBuilder();
}
class MyTcp
{
public delegate void dReceiver(object sender, string b);
public event dReceiver receive;
public Socket WebHabor;
//private bool connected;
public MyTcp(IPEndPoint iep, dReceiver dEventCall)
{
//接收消息的委托;
receive += dEventCall;
//创建socket连接;
WebHabor = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
ObjectState obs = new ObjectState();
obs.obj = this;
obs.client = WebHabor;
WebHabor.BeginConnect(iep, new AsyncCallback(ConnectCallback), obs);
//connected = WebHabor.Connected ? true : false;
Thread.Sleep(10);
if (WebHabor.Connected == true)
{
Receive();
}
else
{
Program.postLog("连接失败，请检查ip和port");
}
}
public static void ExceptionSolver(SocketException sep)
{
switch (sep.SocketErrorCode)
{
case SocketError.NotConnected:
//捕获ip地址输入错误的情况;
Program.postLog("不存在网络连接");
break;
case SocketError.ConnectionAborted:
//在这里处理频繁出现的错误，
//比如IP不对，网线没插
Program.postLog("连接中止");
break;
case SocketError.ConnectionRefused:
//远程主机正在主动拒绝连接;可能是连接的时候ip或port写错了;
Program.postLog("对方不接受连接,更可能是port的原因");
break;
case SocketError.HostUnreachable:
Program.postLog("连接目标不可达");
break;
case SocketError.TimedOut:
//尝试连接ip超时;
Program.postLog("尝试连接ip超时,更可能是ip的原因");
break;
default:
Program.postLog("捕获到" + sep.SocketErrorCode);
//这里直接报错，如果调试的时候出现这里的错误比较多，就移到上面解决，一般问题都是从来不出的
break;
}
}
public void Send(byte[] dataToSend,int byteCount)
{
try
{
WebHabor.BeginSend(dataToSend, 0, byteCount, 0, new AsyncCallback(SendCallback), WebHabor);
//System.Threading.Thread.Sleep(10);//为了让其它线程跑起来;
}
catch (SocketException sep)
{
Program.postLog("在Send这里");
ExceptionSolver(sep);
}
}
public void Receive()
{
byte[] buffer = new byte[256];
ObjectState obs = new ObjectState();
obs.obj = this;//这个传的是MyTcp;
obs.client = WebHabor;
try
{
WebHabor.BeginReceive(obs.buffer, 0, ObjectState.BufferSize, 0, new AsyncCallback(ReceiveCallback), obs);
}
catch (SocketException sep)
{
Program.postLog("在reveive这里");
ExceptionSolver(sep);
}
//receive.Invoke(this, buffer);
}
//beginConnect的回调函数;
private static void ConnectCallback(IAsyncResult ar)
{
ObjectState obs = (ObjectState)ar.AsyncState;
try
{
// Retrieve the socket from the state object.
Socket client = obs.client;
// Complete the connection.
client.EndConnect(ar);
//Console.WriteLine("Socket connected to {0}", client.RemoteEndPoint.ToString());
//连上就连上吧就不发数据了
//MessageBox.Show("Socket connected to " + client.RemoteEndPoint.ToString());
// Signal that the connection has been made.
//connectDone.Set();
}
catch (SocketException sep)
{
//Console.WriteLine(e.ToString());
//MessageBox.Show("connect回调函数出错了" + e.ToString());
/*********************************************************************
*
* 此处需要考察一下连接失败的异常情况。
*
*********************************************************************/
//obs.obj.connected = false;
Program.postLog("在ConnectCallback这里");
ExceptionSolver(sep);
}
}
private static void SendCallback(IAsyncResult ar)
{
try
{
// Retrieve the socket from the state object.
Socket client = (Socket)ar.AsyncState;
//System.Threading.Thread.Sleep(10);//为了让其它线程跑起来;
// Complete sending the data to the remote device.
int bytesSent = client.EndSend(ar);
Program.postLog("本次发送" + bytesSent + "个字节");
//Console.WriteLine("Sent {0} bytes to server.", bytesSent);
//MessageBox.Show("Sent " + bytesSent + " bytes to server.");
// Signal that all bytes have been sent.
//sendDone.Set();
}
catch (SocketException sep)
{
//MessageBox.Show("Send回调函数出错了" + e.ToString());
/*********************************************************************
*
* 此处需要考察一下发送失败的异常情况。
*
*********************************************************************/
Program.postLog("在SendCallback这里");
ExceptionSolver(sep);
}
}
private static void ReceiveCallback(IAsyncResult ar)
{
//byte[] buffer = new byte[256];
try
{
// Retrieve the state object and the client socket
// from the asynchronous state object.
//StateObject state = (StateObject)ar.AsyncState;
//Socket client = state.workSocket;
// Read data from the remote device.
ObjectState objs = (ObjectState)ar.AsyncState;
Socket client = objs.client;
int bytesRead = client.EndReceive(ar);
if (bytesRead > 0)
{
// There might be more data, so store the data received so far.
string getMsg = Encoding.ASCII.GetString(objs.buffer, 0, bytesRead);
//Console.WriteLine("新得到的数据是" + getMsg + "呵呵");
//MessageBox.Show("新得到的数据是" + getMsg);
string msg=Encoding.Default.GetString(objs.buffer, 0, bytesRead);
Program.postLog(msg);
//objs.obj.receive.Invoke(objs.obj, msg);//因为这是静态函数,这个objs.obj实际是MyTcp实例。
//MessageBox.Show(bytesRead.ToString() + "更新数据后:" + state.sb.ToString());
// Get the rest of the data.
client.BeginReceive(objs.buffer, 0, objs.buffer.Length, 0, new AsyncCallback(ReceiveCallback), objs);
}
else
{
//接到0字节说明对方主动断开了连接;
Program.postLog("对方主动断开连接");
}
}
catch (SocketException sep)
{
//MessageBox.Show("Receive回调函数出错了" + e.ToString());
/*********************************************************************
*
* 此处需要考察一下接收失败的异常情况。
*
*********************************************************************/
Program.postLog("在ReceiveCallback这里");
ExceptionSolver(sep);
}
}
}
}

I am not sure, but you can try using TcpClient.Client.Poll method as mentioned in one of the post.

create c# asynchronous socket client in multithreaded environment

I am trying to create asynchronous socket client in multithreaded environment but it is not working correctly.
As below sample code,
If i create new AsyncSocketClient and call StartClent from multi-threaded environment it will process only one or two for rest, it is not processing.(I am creating new AsyncSocketClient with every new request)
Is it because of static variables,
class AsyncSocketClient
{
private static AutoResetEvent sendDone =
new AutoResetEvent(false);
private static AutoResetEvent receiveDone =
new AutoResetEvent(false);
private static ManualResetEvent connectDone =
new ManualResetEvent(false);
static private String response = "";
public void StartClent()
{
Socket workSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
// clientSock.ReceiveTimeout = 1;
try
{
workSocket.BeginConnect(new IPEndPoint(IPAddress.Loopback, 8080), new AsyncCallback(ConnectCallBack), workSocket);
connectDone.WaitOne();
Send(s.workSocket, "<EOF>");
sendDone.WaitOne();
Receive(workSocket);
receiveDone.WaitOne();
}
catch(Exception ex)
{
}
}
private void ConnectCallBack(IAsyncResult ar)
{
Socket workSocket = (Socket)ar.AsyncState;
workSocket.EndConnect(ar);
connectDone.Set();
}
private void Receive(Socket client)
{
StateObject state = new StateObject();
state.workSocket = client;
client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReceiveCallBack), state);
}
private void ReceiveCallBack(IAsyncResult ar)
{
StateObject state = (StateObject)ar.AsyncState;
Socket client = state.workSocket;
int byteReceived= client.EndReceive(ar);
if (byteReceived > 0)
{
state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, state.buffer.Length));
Array.Clear(state.buffer, 0, state.buffer.Length);
client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReceiveCallBack), state);
}
else
{
if (state.sb.Length > 1)
{
response = state.sb.ToString();
}
receiveDone.Set();
}
}
private void Send(Socket client,string data)
{
byte[] sendBufer = Encoding.ASCII.GetBytes(data);
client.BeginSend(sendBufer, 0, sendBufer.Length, 0, new AsyncCallback(BeginSendCallBack), client);
}
private void BeginSendCallBack(IAsyncResult ar)
{
Socket client = (Socket)ar.AsyncState;
int byteSent= client.EndSend(ar);
Console.WriteLine("Sent {0} bytes to server.", byteSent);
sendDone.Set();
}
}
public class StateObject
{
// Client socket.
public Socket workSocket = null;
// Size of receive buffer.
public const int BufferSize = 30;
// Receive buffer.
public byte[] buffer = new byte[BufferSize];
// Received data string.
public StringBuilder sb = new StringBuilder();
}

Here is an example of a non blocking client and server with a simple echo implemented. There is no error checking and nothing is closed correctly which should be done. The server has some synchronous code just to make it easier to follow.
Client
public class AsyncClient
{
private const int Port = 9999;
private readonly string _clientId;
private readonly Random _random;
public AsyncClient(int clientId)
{
_clientId = string.Format("Client Id: {0}", clientId);
_random = new Random(clientId);
}
public void StartClient()
{
try
{
var workSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
var state = new ClientState { WorkSocket = workSocket };
workSocket.BeginConnect(new IPEndPoint(IPAddress.Loopback, Port), ConnectCallBack, state);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
private void ConnectCallBack(IAsyncResult ar)
{
var state = (ClientState) ar.AsyncState;
state.WorkSocket.EndConnect(ar);
Send(state);
}
private void Receive(ClientState clientState)
{
clientState.WorkSocket.BeginReceive(clientState.Buffer, 0, ClientState.BufferSize, 0, ReceiveCallBack, clientState);
}
private void ReceiveCallBack(IAsyncResult ar)
{
var state = (ClientState) ar.AsyncState;
Socket client = state.WorkSocket;
int byteReceived= client.EndReceive(ar);
if (byteReceived > 0)
{
var receivedString = Encoding.UTF8.GetString(state.Buffer, 0, byteReceived);
Console.WriteLine("From Server: " + receivedString);
Array.Clear(state.Buffer, 0, state.Buffer.Length);
state.Count++;
Thread.Sleep(1000 + _random.Next(2000));
Send(state);
}
}
private void Send(ClientState clientState)
{
Console.WriteLine("Sending " + _clientId);
byte[] buffer = Encoding.UTF8.GetBytes(string.Format("Send from Thread {0} Client id {1} Count {2}", Thread.CurrentThread.ManagedThreadId, _clientId,clientState.Count));
clientState.WorkSocket.BeginSend(buffer, 0, buffer.Length, 0, BeginSendCallBack, clientState);
}
private void BeginSendCallBack(IAsyncResult ar)
{
var state = (ClientState) ar.AsyncState;
int byteSent= state.WorkSocket.EndSend(ar);
Console.WriteLine("Sent {0} bytes to server.", byteSent);
Receive(state);
}
}
public class ClientState
{
// Client socket.
public Socket WorkSocket = null;
// Size of receive buffer.
public const int BufferSize = 1024;
// Receive buffer.
public byte[] Buffer = new byte[BufferSize];
public int Count = 0;
}
Server
public class AsyncServer
{
private const int Port = 9999;
public void StartServer()
{
var thread = new Thread(Run) {IsBackground = true};
thread.Start();
}
private void Run()
{
Console.WriteLine("Running");
var tcpListener = new TcpListener(IPAddress.Loopback, Port);
tcpListener.Start();
while (true)
{
Console.WriteLine("Before Accept");
var state = new ServerState {WorkSocket = tcpListener.AcceptSocket()};
Console.WriteLine("Before Recieve");
Receive(state);
}
}
private void Receive(ServerState state)
{
state.WorkSocket.BeginReceive(state.Buffer, 0, ServerState.BufferSize, 0, ReceiveCallBack, state);
}
private void ReceiveCallBack(IAsyncResult ar)
{
Console.WriteLine("ReceiveCallBack");
var state = (ServerState) ar.AsyncState;
try
{
int byteReceived= state.WorkSocket.EndReceive(ar);
if (byteReceived > 0)
{
var receivedString = Encoding.UTF8.GetString(state.Buffer, 0, byteReceived);
Console.WriteLine("Received: " + receivedString);
var bytesToSend = Encoding.UTF8.GetBytes("Server Got --> " + receivedString);
Array.Copy(bytesToSend, state.Buffer, bytesToSend.Length);
state.WorkSocket.Send(state.Buffer, 0, bytesToSend.Length, SocketFlags.None);
Array.Clear(state.Buffer, 0, state.Buffer.Length);
Receive(state);
}
}
catch (Exception e)
{
Console.WriteLine(e);
}
}
private class ServerState
{
public const int BufferSize = 1024;
public readonly byte[] Buffer = new byte[1024];
public Socket WorkSocket;
}
I have run this using a console you can either have two applications or just launch the client and server separately.
static void Main(string[] args)
{
if (args.Length != 0)
{
var server = new AsyncServer();
server.StartServer();
}
else
{
for(int i = 0; i < 10; i++)
{
var client = new AsyncClient(i);
client.StartClient();
}
}
Console.WriteLine("Press a key to exit");
Console.ReadKey();
}

Sockets.Connected is always true?

I have a small file transfer application using WCF service, that send files and folders over tcp sockets.My problem that when i cancel the transfer operation (backgroundworker) from the client, the server still freezed on client.Receive, It supposes to give me this exception: An existing connection was forcibly closed by the remote host ,but it doesn't,despite on the client side the listener.Connected becomes false and socket.Connected becomes false
I need to get this exception and handle it so i can close the stream and the socket and be ready to receive another task!
Client Side:
private void worker_DoWork(object sender, DoWorkEventArgs e)
{
List<Job> Jobs = (List<Job>)e.Argument;
using (Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp))
{
IPEndPoint endpoint = new IPEndPoint(IPAddress.Any, 0);
listener.Bind(endpoint);
listener.Listen(1);
client.ConnectToClient((IPEndPoint)listener.LocalEndPoint);
Socket socket = listener.Accept();
foreach (Job job in Jobs)
{
if (job.IsFile)
{
if (job.IsSend)
{ SendFile(socket, job, e); } //here i send a single file.
// else
// { ReceiveFile(socket, job, e); }
}
// else
// {
// if (job.IsSend)
// { SendDir(socket, job, e); }
// else
// { ReceiveDir(socket, job, e); }
// }
if (worker.CancellationPending)
{
e.Cancel = true;
socket.Dispose();
listener.Dispose();
Console.WriteLine(socket.Connected + " " + listener.Connected);
//it prints "FALSE FALSE"
return;
}
}
}
}
private void SendFile(Socket socket, Job job, DoWorkEventArgs e)
{
UpdateInfo(job.Name, job.Icon); //update GUI with file icon and name.
client.ReceiveFile((_File)job.Argument, bufferSize); //tell the client to start receiving
SendX(socket, ((_File)job.Argument).Path, e); //start sending..
}
private void SendX(Socket socket, string filePath, DoWorkEventArgs e)
{
using (Stream stream = File.OpenRead(filePath))
{
byte[] buffer = new byte[bufferSize];
long sum = 0;
int count = 0;
while (sum < stream.Length)
{
if (worker.CancellationPending)
{
e.Cancel = true;
return;
}
count = stream.Read(buffer, 0, buffer.Length);
socket.Send(buffer, 0, count, SocketFlags.None);
sum += count;
SumAll += count;
worker.ReportProgress((int)((sum * 100) / stream.Length));
}
}
}
Server Side:
public void ConnectToClient(IPEndPoint endpoint)
{
if (client == null)
{
Thread th = new Thread(unused => ConnectTh(endpoint));
th.Start();
}
}
private void ConnectTh(IPEndPoint endpoint)
{
client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
client.Connect(IPAddress.Parse("127.0.0.1"), endpoint.Port);
}
public void ReceiveFile(_File file, int bufferSize)
{
System.Threading.Thread th = new System.Threading.Thread(unused => ReceiveX(client, file.Name, file.Size, bufferSize));
th.Start();
}
private void ReceiveX(Socket client, string destPath, long size, int bufferSize)
{
try
{
using (Stream stream = File.Create(destPath))
{
byte[] buffer = new byte[bufferSize];
long sum = 0;
int count = 0;
while (sum < size)
{
int bytesToReceive = (int)Math.Min(buffer.Length, size - sum);
count = client.Receive(buffer, 0, bytesToReceive, SocketFlags.None);
stream.Write(buffer, 0, count);
sum += count;
}
}
}
catch
{
if (File.Exists(destPath))
File.Delete(destPath);
client.Dispose();
}
}

You should never (have to) count on exceptions for regular program flow.
When the client side shuts down a socket, the server will receive a packet of 0 bytes, and continue to receive that whenever you call Receive. This causes your while loop to last forever. You should handle the situation that count is 0 and treat it as a regular "connection closed by client".
The exception you mentioned only occurs if the client side was unable to shut down properly.

How to receive file from multiple client at a time over TCP connection using C#?

I am having a server and multiple clients in my project. Server need to send the files by request, and it store the files from clients. I have coding, that connects with multiple clients but receives one file at time. Other file store requests will proceed after the previous file received completely.
My files size is around 200 MB. So it takes more time to respond all clients. How i will solve this. Any one help me. Thanks in advance.
public partial class Form1 : Form
{
byte[] Echo;
byte[] a;
Thread t1;
int flag = 0;
string receivedPath = "yok";
public delegate void MyDelegate();
private string fileName;
public Form1()
{
t1 = new Thread(new ThreadStart(StartListening));
t1.Start();
InitializeComponent();
}
delegate void SetTextCallback(string text);
public class StateObject
{
// Client socket.
public Socket workSocket = null;
public const int BufferSize = 8069;
// Receive buffer.
public byte[] buffer = new byte[BufferSize];
}
public static ManualResetEvent allDone = new ManualResetEvent(true);
public void StartListening()
{
StateObject state = new StateObject();
byte[] bytes = new Byte[8069];
IPEndPoint ipEnd = new IPEndPoint(IPAddress.Any, 9050);
Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
try
{
listener.Bind(ipEnd);
listener.Listen(100);
while (true)
{
allDone.Reset();
listener.BeginAccept(new AsyncCallback(AcceptCallback), listener);
allDone.WaitOne();
}
}
catch (Exception ex)
{
SetText(ex.ToString());
}
}
public void AcceptCallback(IAsyncResult ar)
{
Socket listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
StateObject state = new StateObject();
state.workSocket = handler;
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, SocketFlags.None, new AsyncCallback(ReadCallback), state);
flag = 0;
}
public void ReadCallback(IAsyncResult ar)
{
int fileNameLen = 1;
String content = String.Empty;
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
try
{
int bytesRead = handler.EndReceive(ar);
if (bytesRead > 0)
{
if (flag == 0)
{
fileNameLen = BitConverter.ToInt32(state.buffer, 0);
fileName = Encoding.UTF8.GetString(state.buffer, 4, fileNameLen);
receivedPath = #"D:\" + fileName;
flag++;
}
if (flag >= 1)
{
BinaryWriter writer = new BinaryWriter(File.Open(receivedPath, FileMode.Append));
if (flag == 1)
{
writer.Write(state.buffer, 4 + fileNameLen, bytesRead - (4 + fileNameLen));
flag++;
}
else
writer.Write(state.buffer, 0, bytesRead);
writer.Close();
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, SocketFlags.None, new AsyncCallback(ReadCallback), state);
}
}
else
{
allDone.Set();
Invoke(new MyDelegate(LabelWriter));
}
}
catch
{
}
}
public void LabelWriter()
{
label1.Text = "Data has been received " + fileName;
}
private void Form1_FormClosed(object sender, FormClosedEventArgs e)
{
t1.Abort();
}
}

You can trigger your allDone event within the AcceptCallback method. Immidiatly after accepting a client, you can spin of a process that is communicating with that client while in the meantime start listening for the next client.