Turn you Monitor off from your application.

public partial class Form1 : Form
        public int WM_SYSCOMMAND = 0x0112;
        public int SC_MONITORPOWER = 0xF170; 
        private static extern int SendMessage(int hWnd, int hMsg, int wParam, int lParam);

        public Form1()

        private void button1_Click(object sender, EventArgs e)
            SendMessage( this.Handle.ToInt32() , WM_SYSCOMMAND , SC_MONITORPOWER ,2 );//DLL function


Thats cool.

it does not work
please help.

Error 1 The type or namespace name 'DllImport' could not be found (are you missing a using directive or an assembly reference?) E:\Windows Application\TEST APPLICATION\TurnOffMonitor\TurnOffMonitor\Form1.cs 19 10 TurnOffMonitor

use namespace

using System.Runtime.InteropServices;