ForegroundVsBackgroundWinForms.cs

using System;
using System.Drawing;
using System.Threading;
using System.Windows.Forms;

namespace Recetas.Multithreading.Cap01.R0107
{
    public class ForegroundVsBackgroundWinForms : Form
    {
        private System.ComponentModel.IContainer components = null;

        public ForegroundVsBackgroundWinForms()
        {
            InitializeComponents();
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                if (components != null)
                {
                    components.Dispose();
                }
            }
            base.Dispose (disposing);
        }

        protected void InitializeComponents()
        {
            this.SuspendLayout();
            this.Font = new Font ("Trebuchet MS", 9);
            this.FormBorderStyle = FormBorderStyle.FixedSingle;
            this.MaximizeBox = false;
            this.Name = "frmForegroundVsBackground";
            this.Size = new Size (650, 231);
            this.Text = "Foreground Vs Background Thread";

            CrearBotones();
        }

        private void CrearBotones()
        {
            Button btnCrearBackgroundThread = new Button();
            btnCrearBackgroundThread.Click += btnCrearBackgroundThread_Click;
            btnCrearBackgroundThread.Location = new Point (17, 17);
            btnCrearBackgroundThread.Name = "btnCrearBackgroundThread";
            btnCrearBackgroundThread.Size = new Size (153, 23);
            btnCrearBackgroundThread.Text = "Crear Thread Background";
            this.Controls.Add (btnCrearBackgroundThread);

            Button btnCrearForegroundThread = new Button ();
            btnCrearForegroundThread.AutoSize = true;
            btnCrearForegroundThread.Click += btnCrearForegroundThread_Click;
            btnCrearForegroundThread.Location = new Point (201, 17);
            btnCrearForegroundThread.Name = "btnCrearForegroundThread";
            btnCrearForegroundThread.Size = new Size (153,23);
            btnCrearForegroundThread.Text = "Crear Thread Foreground";
            this.Controls.Add (btnCrearForegroundThread);

            Label lblInstrucciones = new Label ();
            lblInstrucciones.AutoSize = true;
            lblInstrucciones.Location = new Point (17, 103);
            lblInstrucciones.Text = String.Format ("Pasos:\n{0}\n{1}\n{2}",
                "1. Inicie el Administrador de Tareas y seleccione el proceso ForegroundVsBackgroundWinForms.exe \n    desde la pestaña Procesos.",
                "2. Prueba primero con uno de los botones y cierre la aplicación.",
                "3. Observe lo qué sucede después de cada clic en el Administrador de Tareas."
            );
            this.Controls.Add (lblInstrucciones);
        }

        public void btnCrearBackgroundThread_Click (object sender, EventArgs e)
        {
            // Crea un thread para ejecutarlo en segundo plano:
            Thread t = new Thread (Retraso);
            t.IsBackground = true;
            t.Start();

            MessageBox.Show ("Se ha invocado un thread que tomará 13 segundos en completarse.\n" +
                             "Cierre la aplicación y observe lo que sucede en el Administrador de Tareas");
        }

        public void btnCrearForegroundThread_Click(object sender, EventArgs e)
        {
            // Crea un thread para ejecución en primer plano:
            Thread t = new Thread (Retraso);
            t.IsBackground = false;
            t.Start();

            MessageBox.Show ("Se ha invocado un thread que tomará 13 segundos en completarse.\n" +
                             "Cierre la aplicación y observe lo que sucede en el Administrador de Tareas");
        }

        private void Retraso()
        {
            Thread.Sleep (TimeSpan.FromSeconds (10));
        }

        [STAThread]
        public static void Main()
        {
            Application.EnableVisualStyles();
            Application.Run (new ForegroundVsBackgroundWinForms());
        }
    }
}