Csharp/CSharp Tutorial/Network/Socket Client

Echo Client without message encoding

using System;
using System.IO;
using System.Net.Sockets;
class MainClass
{
  const int echoPort = 7;
  [STAThread]
  static void Main(string[] args)
  {
    using ( TcpClient tc = new TcpClient( "localhost", echoPort ) )
    {
      NetworkStream ns = tc.GetStream();
      StreamWriter sw = new StreamWriter( ns );
      StreamReader sr = new StreamReader( ns );
      sw.WriteLine( "test message" );
      sw.Flush();
      System.Console.WriteLine( sr.ReadLine() );
    }
  }
}

Echo Client with UTF8 Encoding

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
class MainClass
{
  const int echoPort = 7;
  [STAThread]
  static void Main( string[] args )
  {
    Socket s = new Socket( AddressFamily.InterNetwork, 
      SocketType.Stream, 
      ProtocolType.Tcp );
    s.Connect( new IPEndPoint( IPAddress.Loopback, echoPort ) );
    UTF8Encoding enc = new UTF8Encoding();
    s.Send( enc.GetBytes( "test message" ) );
    Byte[] buff = new Byte[ 1024 ];
    s.Receive( buff );
    System.Console.WriteLine( enc.GetString( buff ) );
  }
}

GUI based Tcp Client

/*
Quote from 
C# Network Programming
# Paperback: 656 pages
# Publisher: Sybex (November 26, 2002)
# Language: English
# ISBN-10: 0782141765
# ISBN-13: 978-0782141764
*/
using System;
using System.Drawing;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Windows.Forms;
public class AsyncTcpClient : Form
{
   private TextBox newText;
   private TextBox conStatus;
   private ListBox results;
   private Socket client;
   private byte[] data = new byte[1024];
   private int size = 1024;
   public AsyncTcpClient()
   {
      Text = "Asynchronous TCP Client";
      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, 18 * Font.Height);
      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 = "Disconnected";
      conStatus.Size = new Size(200, 2 * Font.Height);
      conStatus.Location = new Point(110, 325);
      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 discon = new Button();
      discon.Parent = this;
      discon.Text = "Disconnect";
      discon.Location = new Point(295,52);
      discon.Size = new Size(6 * Font.Height, 2 * Font.Height);
      discon.Click += new EventHandler(ButtonDisconOnClick);
   }
   void ButtonConnectOnClick(object obj, EventArgs ea)
   {
      conStatus.Text = "Connecting...";
      Socket newsock = new Socket(AddressFamily.InterNetwork,
                            SocketType.Stream, ProtocolType.Tcp);
      IPEndPoint iep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9050);
      newsock.BeginConnect(iep, new AsyncCallback(Connected), newsock);
   }
   void ButtonSendOnClick(object obj, EventArgs ea)
   {
      byte[] message = Encoding.ASCII.GetBytes(newText.Text);
      newText.Clear();
      client.BeginSend(message, 0, message.Length, SocketFlags.None, new AsyncCallback(SendData), client);
   }
   void ButtonDisconOnClick(object obj, EventArgs ea)
   {
      client.Close();
      conStatus.Text = "Disconnected";
   }
   void Connected(IAsyncResult iar)
   {
      client = (Socket)iar.AsyncState;
      try
      {
         client.EndConnect(iar);
         conStatus.Text = "Connected to: " + client.RemoteEndPoint.ToString();
         client.BeginReceive(data, 0, size, SocketFlags.None,
                       new AsyncCallback(ReceiveData), client);
      } catch (SocketException)
      {
         conStatus.Text = "Error connecting";
      }
   }
   void ReceiveData(IAsyncResult iar)
   {
      Socket remote = (Socket)iar.AsyncState;
      int recv = remote.EndReceive(iar);
      string stringData = Encoding.ASCII.GetString(data, 0, recv);
      results.Items.Add(stringData);
   }
   void SendData(IAsyncResult iar)
   {
      Socket remote = (Socket)iar.AsyncState;
      int sent = remote.EndSend(iar);
      remote.BeginReceive(data, 0, size, SocketFlags.None,new AsyncCallback(ReceiveData), remote);
   }
   public static void Main()
   {
      Application.Run(new AsyncTcpClient());
   }
}

Send data using Socket

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
class MainClass
{
   public static void Main()
   {
      IPAddress host = IPAddress.Parse("192.168.1.1");
      IPEndPoint hostep = new IPEndPoint(host, 8000);
      Socket sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
      try
      {
         sock.Connect(hostep);
      } catch (SocketException e) {
         Console.WriteLine("Problem connecting to host");
         Console.WriteLine(e.ToString());
         sock.Close();
         return;
      }
      try
      {
         sock.Send(Encoding.ASCII.GetBytes("testing"));
      } catch (SocketException e) {
          Console.WriteLine("Problem sending data");
          Console.WriteLine( e.ToString());
          sock.Close();
          return;
      }
      sock.Close();
   }
}

Simple Tcp Client: receive data from server

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
class MainClass
{
   public static void Main()
   {
      IPEndPoint ip = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9999);
      Socket server = new Socket(AddressFamily.InterNetwork,SocketType.Stream, ProtocolType.Tcp);
      try
      {
         server.Connect(ip);
      } catch (SocketException e){
         Console.WriteLine("Unable to connect to server.");
         return;
      }
      byte[] data = new byte[1024];
      int receivedDataLength = server.Receive(data);
      string stringData = Encoding.ASCII.GetString(data, 0, receivedDataLength);
      Console.WriteLine(stringData);
      server.Shutdown(SocketShutdown.Both);
      server.Close();
   }
}

Simple Tcp Client: send data to the server

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
class MainClass
{
   public static void Main()
   {
      IPEndPoint ip = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9999);
      Socket server = new Socket(AddressFamily.InterNetwork,SocketType.Stream, ProtocolType.Tcp);
      try
      {
         server.Connect(ip);
      } catch (SocketException e){
         Console.WriteLine("Unable to connect to server.");
         return;
      }
      Console.WriteLine("Type "exit" to exit.");
      while(true)
      {
         string input = Console.ReadLine();
         if (input == "exit")
            break;
         server.Send(Encoding.ASCII.GetBytes(input));
         byte[] data = new byte[1024];
         int receivedDataLength = server.Receive(data);
         string stringData = Encoding.ASCII.GetString(data, 0, receivedDataLength);
         Console.WriteLine(stringData);
      }
      server.Shutdown(SocketShutdown.Both);
      server.Close();
   }
}

Simple Tcp server: send data to the client

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
class MainClass
{
   public static void Main()
   {
      IPEndPoint ip = new IPEndPoint(IPAddress.Any,9999);
      Socket socket = new Socket(AddressFamily.InterNetwork,SocketType.Stream, ProtocolType.Tcp);
      socket.Bind(ip);
      socket.Listen(10);
      Console.WriteLine("Waiting for a client...");
      Socket client = socket.Accept();
      IPEndPoint clientep =(IPEndPoint)client.RemoteEndPoint;
      Console.WriteLine("Connected with {0} at port {1}",clientep.Address, clientep.Port);
      
      string welcome = "Welcome";
      byte[] data = new byte[1024];
      data = Encoding.ASCII.GetBytes(welcome);
      client.Send(data, data.Length,SocketFlags.None);
      Console.WriteLine("Disconnected from {0}",clientep.Address);
      client.Close();
      socket.Close();
   }
}

Socket connection

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
class MainClass
{
   public static void Main()
   {
      IPAddress host = IPAddress.Parse("192.168.1.1");
      IPEndPoint hostep = new IPEndPoint(host, 8000);
      Socket sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
      try
      {
         sock.Connect(hostep);
      } catch (SocketException e) {
         Console.WriteLine("Problem connecting to host");
         Console.WriteLine(e.ToString());
         sock.Close();
         return;
      }
      sock.Close();
   }
}