Chat continuo

A continuación se muestra la implementación de un chat bidireccional con multihilo para evitar que la interfaz se quede congelada.

La versión WinForm emplea BackgroundWorker para ejecutar el bucle de recepción en un hilo independiente, mientras que el envío de mensajes se dispara desde el hilo de la interfaz. Esto salta esta limitación y permite un chat bidireccional sin restricciones.

Primero el código del lado del servidor

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Windows.Forms;

namespace Service
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            Control.CheckForIllegalCrossThreadCalls = false;
        }

        IPAddress ip;
        TcpListener listener;
        TcpClient tcpClient;

        private void buttonStart_Click(object sender, EventArgs e)
        {
            this.backgroundWorker1.RunWorkerAsync();
        }

        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            ip = IPAddress.Parse(this.textBoxIP.Text);
            listener = new TcpListener(ip, Convert.ToInt32(this.textBoxPort.Text));
            listener.Start();
            this.textBoxInfo.Text = "Servidor iniciado - " + DateTime.Now.ToShortTimeString() + "\r\n" + this.textBoxInfo.Text;
            tcpClient = listener.AcceptTcpClient();
            this.textBoxInfo.Text = "Conexión establecida - " + DateTime.Now.ToShortTimeString() + "\r\n" + this.textBoxInfo.Text;

            NetworkStream stream = tcpClient.GetStream();
            byte[] byteArray = new byte[1024];
            while (true)
            {
                int length = stream.Read(byteArray, 0, 1024);
                string receiveMessage = Encoding.Unicode.GetString(byteArray, 0, length);
                this.textBoxInfo.Text = "Recibido: " + receiveMessage + " - " + DateTime.Now.ToShortTimeString() + "\r\n" + this.textBoxInfo.Text;
            }
        }

        private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {

        }

        private void buttonSend_Click(object sender, EventArgs e)
        {
            string message = this.textBoxInput.Text;
            this.textBoxInfo.Text = "Enviado \"" + message + "\" - " + DateTime.Now.ToShortTimeString() + "\r\n" + this.textBoxInfo.Text;
            NetworkStream stream = tcpClient.GetStream();
            byte[] byteArray = Encoding.Unicode.GetBytes(message);
            stream.Write(byteArray, 0, byteArray.Length);
        }
    }
}
Lenguaje del código: C# (cs)

Ahora el código del lado del cliente

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net.Sockets;
using System.Text;
using System.Windows.Forms;

namespace Client
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            Control.CheckForIllegalCrossThreadCalls = false;
        }
        TcpClient tcpClient;
        private void buttonStart_Click(object sender, EventArgs e)
        {
            tcpClient = new TcpClient();
            try
            {
                tcpClient.Connect(this.textBoxIP.Text, Convert.ToInt32(this.textBoxPort.Text));
                this.textBoxInfo.Text = "Conexión establecida - " + DateTime.Now.ToShortTimeString() + "\r\n" + this.textBoxInfo.Text;
                this.backgroundWorker1.RunWorkerAsync();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Fallo de conexión - "+ex.Message);
            }
        }

        private void buttonSend_Click(object sender, EventArgs e)
        {
            string message = this.textBoxInput.Text;
            this.textBoxInfo.Text = "Enviado \""+message+"\" - " + DateTime.Now.ToShortTimeString() + "\r\n" + this.textBoxInfo.Text;
            NetworkStream stream = tcpClient.GetStream();
            byte[] byteArray = Encoding.Unicode.GetBytes(message);
            stream.Write(byteArray, 0, byteArray.Length);
        }

        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            NetworkStream stream = tcpClient.GetStream();
            byte[] byteArray = new byte[1024];
            while (true)
            {
                int length = stream.Read(byteArray, 0, 1024);
                string receiveMessage = Encoding.Unicode.GetString(byteArray, 0, length);
                this.textBoxInfo.Text = "Recibido: " + receiveMessage + " - " + DateTime.Now.ToShortTimeString() + "\r\n" + this.textBoxInfo.Text;
            }
        }
    }
}
Lenguaje del código: C# (cs)

Chat continuo