/*
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.Threading;
using System.Windows.Forms;
public class NewTcpChat : Form
{
private static TextBox newText;
private static ListBox results;
private static ListBox hosts;
private static Socket client;
private static byte[] data = new byte[1024];
public NewTcpChat()
{
Text = "New TCP Chat Program";
Size = new Size(400, 380);
Label label1 = new Label();
label1.Parent = this;
label1.Text = "Enter text string:";
label1.AutoSize = true;
label1.Location = new Point(10, 30);
newText = new TextBox();
newText.Parent = this;
newText.Size = new Size(200, 2 * Font.Height);
newText.Location = new Point(10, 55);
results = new ListBox();
results.Parent = this;
results.Location = new Point(10, 85);
results.Size = new Size(360, 10 * Font.Height);
Label label2 = new Label();
label2.Parent = this;
label2.Text = "Active hosts";
label2.AutoSize = true;
label2.Location = new Point(10, 240);
hosts = new ListBox();
hosts.Parent = this;
hosts.Location = new Point(10, 255);
hosts.Size = new Size(360, 5 * Font.Height);
Button sendit = new Button();
sendit.Parent = this;
sendit.Text = "Send";
sendit.Location = new Point(220,52);
sendit.Size = new Size(5 * Font.Height, 2 * Font.Height);
sendit.Click += new EventHandler(ButtonSendOnClick);
Button connect = new Button();
connect.Parent = this;
connect.Text = "Connect";
connect.Location = new Point(295, 20);
connect.Size = new Size(6 * Font.Height, 2 * Font.Height);
connect.Click += new EventHandler(ButtonConnectOnClick);
Button listen = new Button();
listen.Parent = this;
listen.Text = "Listen";
listen.Location = new Point(295,52);
listen.Size = new Size(6 * Font.Height, 2 * Font.Height);
listen.Click += new EventHandler(ButtonListenOnClick);
Thread fh = new Thread(new ThreadStart(findHosts));
fh.IsBackground = true;
fh.Start();
}
void ButtonListenOnClick(object obj, EventArgs ea)
{
results.Items.Add("Listening for a client...");
Socket newsock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
IPEndPoint iep = new IPEndPoint(IPAddress.Any, 9050);
newsock.Bind(iep);
newsock.Listen(5);
newsock.BeginAccept(new AsyncCallback(AcceptConn), newsock);
Thread advertise = new Thread(new ThreadStart(srvrAdvertise));
advertise.IsBackground = true;
advertise.Start();
}
void ButtonConnectOnClick(object obj, EventArgs ea)
{
results.Items.Add("Connecting...");
client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
string selectedhost = (string)hosts.SelectedItem;
string[] hostarray = selectedhost.Split(':');
IPEndPoint iep = new IPEndPoint(IPAddress.Parse(hostarray[1]), 9050);
client.BeginConnect(iep, new AsyncCallback(Connected), client);
}
void ButtonSendOnClick(object obj, EventArgs ea)
{
byte[] message = Encoding.ASCII.GetBytes(newText.Text);
newText.Clear();
client.BeginSend(message, 0, message.Length, 0, new AsyncCallback(SendData), client);
}
void AcceptConn(IAsyncResult iar)
{
Socket oldserver = (Socket)iar.AsyncState;
client = oldserver.EndAccept(iar);
results.Items.Add("Connection from: " + client.RemoteEndPoint.ToString());
Thread receiver = new Thread(new ThreadStart(ReceiveData));
receiver.IsBackground = true;
receiver.Start();
}
void Connected(IAsyncResult iar)
{
try
{
client.EndConnect(iar);
results.Items.Add("Connected to: " + client.RemoteEndPoint.ToString());
Thread receiver = new Thread(new ThreadStart(ReceiveData));
receiver.IsBackground = true;
receiver.Start();
} catch (SocketException)
{
results.Items.Add("Error connecting");
}
}
void SendData(IAsyncResult iar)
{
Socket remote = (Socket)iar.AsyncState;
int sent = remote.EndSend(iar);
}
void ReceiveData()
{
int recv;
string stringData;
while (true)
{
recv = client.Receive(data);
stringData = Encoding.ASCII.GetString(data, 0, recv);
if (stringData == "bye")
break;
results.Items.Add(stringData);
}
stringData = "bye";
byte[] message = Encoding.ASCII.GetBytes(stringData);
client.Send(message);
client.Close();
results.Items.Add("Connection stopped");
return;
}
void srvrAdvertise()
{
Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
server.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);
IPEndPoint iep = new IPEndPoint(IPAddress.Broadcast, 9051);
byte[] hostname = Encoding.ASCII.GetBytes(Dns.GetHostName());
while (true)
{
server.SendTo(hostname, iep);
Thread.Sleep(60000);
}
}
void findHosts()
{
while(true)
{
Socket remoteHosts = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
IPEndPoint iep = new IPEndPoint(IPAddress.Any, 9051);
EndPoint ep = (EndPoint)iep;
remoteHosts.Bind(iep);
byte[] data = new byte[1024];
int recv = remoteHosts.ReceiveFrom(data, ref ep);
string stringData = Encoding.ASCII.GetString(data, 0, recv);
string entry = stringData + ":" + ep.ToString();
if (!hosts.Items.Contains(entry))
hosts.Items.Add(entry);
}
}
public static void Main()
{
Application.Run(new NewTcpChat());
}
}
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