/*
C# Network Programming
by Richard Blum
Publisher: Sybex
ISBN: 0782141765
*/
using System;
using System.Drawing;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Windows.Forms;
public class AsyncTcpSrvr : Form
{
private TextBox conStatus;
private ListBox results;
private byte[] data = new byte[1024];
private int size = 1024;
private Socket server;
public AsyncTcpSrvr()
{
Text = "Asynchronous TCP Server";
Size = new Size(400, 380);
results = new ListBox();
results.Parent = this;
results.Location = new Point(10, 65);
results.Size = new Size(350, 20 * Font.Height);
Label label1 = new Label();
label1.Parent = this;
label1.Text = "Text received from client:";
label1.AutoSize = true;
label1.Location = new Point(10, 45);
Label label2 = new Label();
label2.Parent = this;
label2.Text = "Connection Status:";
label2.AutoSize = true;
label2.Location = new Point(10, 330);
conStatus = new TextBox();
conStatus.Parent = this;
conStatus.Text = "Waiting for client...";
conStatus.Size = new Size(200, 2 * Font.Height);
conStatus.Location = new Point(110, 325);
Button stopServer = new Button();
stopServer.Parent = this;
stopServer.Text = "Stop Server";
stopServer.Location = new Point(260,32);
stopServer.Size = new Size(7 * Font.Height, 2 * Font.Height);
stopServer.Click += new EventHandler(ButtonStopOnClick);
server = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
IPEndPoint iep = new IPEndPoint(IPAddress.Any, 9050);
server.Bind(iep);
server.Listen(5);
server.BeginAccept(new AsyncCallback(AcceptConn), server);
}
void ButtonStopOnClick(object obj, EventArgs ea)
{
Close();
}
void AcceptConn(IAsyncResult iar)
{
Socket oldserver = (Socket)iar.AsyncState;
Socket client = oldserver.EndAccept(iar);
conStatus.Text = "Connected to: " + client.RemoteEndPoint.ToString();
string stringData = "Welcome to my server";
byte[] message1 = Encoding.ASCII.GetBytes(stringData);
client.BeginSend(message1, 0, message1.Length, SocketFlags.None,
new AsyncCallback(SendData), client);
}
void SendData(IAsyncResult iar)
{
Socket client = (Socket)iar.AsyncState;
int sent = client.EndSend(iar);
client.BeginReceive(data, 0, size, SocketFlags.None,
new AsyncCallback(ReceiveData), client);
}
void ReceiveData(IAsyncResult iar)
{
Socket client = (Socket)iar.AsyncState;
int recv = client.EndReceive(iar);
if (recv == 0)
{
client.Close();
conStatus.Text = "Waiting for client...";
server.BeginAccept(new AsyncCallback(AcceptConn), server);
return;
}
string receivedData = Encoding.ASCII.GetString(data, 0, recv);
results.Items.Add(receivedData);
byte[] message2 = Encoding.ASCII.GetBytes(receivedData);
client.BeginSend(message2, 0, message2.Length, SocketFlags.None,
new AsyncCallback(SendData), client);
}
public static void Main()
{
Application.Run(new AsyncTcpSrvr());
}
}