I want to receive new messages from server in a loop. But when I use the code below, it stops on receiveDone in while loop. And it doesn't receive any message from server. How to change the below code or write a new one, which receives messages and popup them on screen.
// State object for receiving data from remote device. public class StateObject < // Client socket. public Socket workSocket = null; // Size of receive buffer. public const int BufferSize = 256; // Receive buffer. public byte[] buffer = new byte[BufferSize]; // Received data string. public StringBuilder sb = new StringBuilder(); >public class AsynchronousClient < // The port number for the remote device. private const int port = 1200; // ManualResetEvent instances signal completion. private static ManualResetEvent connectDone = new ManualResetEvent(false); private static ManualResetEvent sendDone = new ManualResetEvent(false); private static ManualResetEvent receiveDone = new ManualResetEvent(false); // The response from the remote device. private static String response = String.Empty; private static void StartClient() < // Connect to a remote device. try < // Establish the remote endpoint for the socket. IPAddress ipAddress = IPAddress.Parse("127.0.0.1"); IPEndPoint remoteEP = new IPEndPoint(ipAddress, port); // Create a TCP/IP socket. Socket client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); // Connect to the remote endpoint. client.BeginConnect( remoteEP, new AsyncCallback(ConnectCallback), client); connectDone.WaitOne(); // Send data to the remote device. Send(client,"HELLO"); sendDone.WaitOne(); while(true) < Receive(client); receiveDone.WaitOne(); if(!string.IsNullOrWhiteSpace(response)) Console.WriteLine(response); >// Release the socket. client.Shutdown(SocketShutdown.Both); client.Close(); > catch (Exception e) < Console.WriteLine(e.ToString()); >> private static void ConnectCallback(IAsyncResult ar) < // Retrieve the socket from the state object. Socket client = (Socket) ar.AsyncState; // Complete the connection. client.EndConnect(ar); Console.WriteLine("Socket connected to ", client.RemoteEndPoint.ToString()); // Signal that the connection has been made. connectDone.Set(); > private static void Receive(Socket client) < // Create the state object. StateObject state = new StateObject(); state.workSocket = client; // Begin receiving the data from the remote device. client.BeginReceive( state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReceiveCallback), state); >private static void ReceiveCallback(IAsyncResult ar) < // 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. int bytesRead = client.EndReceive(ar); if (bytesRead >0) < // There might be more data, so store the data received so far. state.sb.Append(Encoding.ASCII.GetString(state.buffer,0,bytesRead)); // Get the rest of the data. client.BeginReceive(state.buffer,0,StateObject.BufferSize,0, new AsyncCallback(ReceiveCallback), state); >else < // All the data has arrived; put it in response. if (state.sb.Length >1) < response = state.sb.ToString(); >// Signal that all bytes have been received. receiveDone.Set(); > > private static void Send(Socket client, String data) < // Convert the string data to byte data using ASCII encoding. byte[] byteData = Encoding.ASCII.GetBytes(data); // Begin sending the data to the remote device. client.BeginSend(byteData, 0, byteData.Length, 0, new AsyncCallback(SendCallback), client); >private static void SendCallback(IAsyncResult ar) < // Retrieve the socket from the state object. Socket client = (Socket) ar.AsyncState; // Complete sending the data to the remote device. int bytesSent = client.EndSend(ar); Console.WriteLine("Sent bytes to server.", bytesSent); // Signal that all bytes have been sent. sendDone.Set(); > public static int Main(String[] args) < StartClient(); return 0; >> You are getting an exception and exiting the program. Try following fix :
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Net; using System.Net.Sockets; using System.Threading; namespace ConsoleApplication48 < class Program < public class StateObject < // Client socket. public Socket workSocket = null; // Size of receive buffer. public const int BufferSize = 256; // Receive buffer. public byte[] buffer = new byte[BufferSize]; // Received data string. public StringBuilder sb = new StringBuilder(); >public class AsynchronousClient < // The port number for the remote device. private const int port = 1200; // ManualResetEvent instances signal completion. private static ManualResetEvent connectDone = new ManualResetEvent(false); private static ManualResetEvent sendDone = new ManualResetEvent(false); private static ManualResetEvent receiveDone = new ManualResetEvent(false); // The response from the remote device. private static String response = String.Empty; private static void StartClient() < // Connect to a remote device. try < string LocalHostName = Dns.GetHostName(); IPHostEntry LocalHostIPEntry = Dns.GetHostEntry(LocalHostName); ; IPAddress ipAddress = LocalHostIPEntry.AddressList.Where(x =>!x.IsIPv6LinkLocal).FirstOrDefault(); IPEndPoint remoteEP = new IPEndPoint(ipAddress, port); // Create a TCP/IP socket. Socket client = new Socket(ipAddress.AddressFamily, SocketType.Stream, ProtocolType.Tcp); // Connect to the remote endpoint. client.BeginConnect(remoteEP, new AsyncCallback(ConnectCallback), client); connectDone.WaitOne(); // Send data to the remote device. Send(client, "HELLO"); sendDone.WaitOne(); while (true) < Receive(client); receiveDone.WaitOne(); if (!string.IsNullOrWhiteSpace(response)) Console.WriteLine(response); >// Release the socket. client.Shutdown(SocketShutdown.Both); client.Close(); > catch (Exception e) < Console.WriteLine(e.ToString()); >> private static void ConnectCallback(IAsyncResult ar) < // Retrieve the socket from the state object. Socket client = (Socket)ar.AsyncState; // Complete the connection. client.EndConnect(ar); Console.WriteLine("Socket connected to ", client.RemoteEndPoint.ToString()); // Signal that the connection has been made. connectDone.Set(); > private static void Receive(Socket client) < // Create the state object. StateObject state = new StateObject(); state.workSocket = client; // Begin receiving the data from the remote device. client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReceiveCallback), state); >private static void ReceiveCallback(IAsyncResult ar) < // 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. int bytesRead = client.EndReceive(ar); if (bytesRead >0) < // There might be more data, so store the data received so far. state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead)); Send(client, "HELLO"); // Get the rest of the data. client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReceiveCallback), state); >else < // All the data has arrived; put it in response. if (state.sb.Length >1) < response = state.sb.ToString(); >// Signal that all bytes have been received. receiveDone.Set(); > > private static void Send(Socket client, String data) < // Convert the string data to byte data using ASCII encoding. byte[] byteData = Encoding.ASCII.GetBytes(data); // Begin sending the data to the remote device. client.BeginSend(byteData, 0, byteData.Length, 0, new AsyncCallback(SendCallback), client); >private static void SendCallback(IAsyncResult ar) < // Retrieve the socket from the state object. Socket client = (Socket)ar.AsyncState; // Complete sending the data to the remote device. int bytesSent = client.EndSend(ar); Console.WriteLine("Sent bytes to server.", bytesSent); // Signal that all bytes have been sent. sendDone.Set(); > public static void AcceptCallback(IAsyncResult ar) < // Signal the main thread to continue. // Get the socket that handles the client request. TcpListener listener = (TcpListener) ar.AsyncState; Socket handler = listener.Server.EndAccept(ar); // Create the state object. StateObject state = new StateObject(); state.workSocket = handler; handler.BeginReceive( state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ListenerReadCallback), state); >public static void ListenerReadCallback(IAsyncResult ar) < String content = String.Empty; // Retrieve the state object and the handler socket // from the asynchronous state object. StateObject state = (StateObject) ar.AsyncState; Socket handler = state.workSocket; // Read data from the client socket. int bytesRead = handler.EndReceive(ar); if (bytesRead >0) < handler.BeginSend(state.buffer, 0, bytesRead, 0, new AsyncCallback(ListenerSendCallback), handler); >// Not all data received. Get more. handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ListenerReadCallback), state); > private static void ListenerSendCallback(IAsyncResult ar) < Socket handler = (Socket)ar.AsyncState; int bytesSent = handler.EndSend(ar); >static void Main(string[] args) < TcpListener listener = new TcpListener(IPAddress.Any, 1200); listener.Start(); listener.Server.BeginAccept( new AsyncCallback(AcceptCallback), listener ); StartClient(); >> > >