PowerShell: Turn off computer screen

turn-off-screen.ps1

# Source: http://www.powershellmagazine.com/2013/07/18/pstip-how-to-switch-off-display-with-powershell/

# Turn display off by calling WindowsAPI.
 
# SendMessage(HWND_BROADCAST,WM_SYSCOMMAND, SC_MONITORPOWER, POWER_OFF)
# HWND_BROADCAST  0xffff
# WM_SYSCOMMAND   0x0112
# SC_MONITORPOWER 0xf170
# POWER_OFF       0x0002
 
Add-Type -TypeDefinition '
using System;
using System.Runtime.InteropServices;
 
namespace Utilities {
   public static class Display
   {
      [DllImport("user32.dll", CharSet = CharSet.Auto)]
      private static extern IntPtr SendMessage(
         IntPtr hWnd,
         UInt32 Msg,
         IntPtr wParam,
         IntPtr lParam
      );
 
      public static void PowerOff ()
      {
         SendMessage(
            (IntPtr)0xffff, // HWND_BROADCAST
            0x0112,         // WM_SYSCOMMAND
            (IntPtr)0xf170, // SC_MONITORPOWER
            (IntPtr)0x0002  // POWER_OFF
         );
      }
   }
}
'

[Utilities.Display]::PowerOff()

Works like a charm.
The script doesn't seem to terminate tho - how do I close the window automatically after it turned the display(s) off?

@TrueMilli how do you run the script?

@oledid In Powershell or PowerShell ISE, doesn't matter. My workaround is to call it from a wrapper:

$process = Start-Process -FilePath $PSScriptRoot\DisplayOffMethod.ps1 -PassThru
Start-Sleep 3
Stop-Process $process

@TrueMilli great that you found a workaround.

@TrueMilli found an even better solution. Replace SendMessage with PostMessage, PostMessage work asynchronous and does not cause the script to hang!

@oledid you might want to replace that in your snippet if you find that appropriate.

@PCHSwS I don't maintain the script unless I need to use it again, but people can see your comments here - and here's even a link to your fork: https://gist.github.com/PCHSwS/39e213aac7c574b89673da8dc575e7fa

Is there a possibility to pick which from X monitors we can disable?