Compile.bat

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\csc.exe DisplayStandBy.cs

DisplayStandBy.cs

using System;
using System.Runtime.InteropServices;

namespace Monitor
{
    class Power
    {
        const int HWND_BROADCAST  = 0xffff;
        const int WM_SYSCOMMAND   = 0x0112;
        const int SC_MONITORPOWER = 0xF170;
        
        [DllImport("user32.dll")]
        public static extern bool PostMessage(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam);
        
        static void Main()
        {
            System.Threading.Thread.Sleep(1000);
            PowerOff();
        }
        
        static void PowerOff()
        {
            PostMessage((IntPtr)HWND_BROADCAST, WM_SYSCOMMAND, new IntPtr(SC_MONITORPOWER), new IntPtr(2));
        }
    }
}