Get monitor state

Posted on 2004-10-08
Last Modified: 2010-04-05

Is it possible to get the state of the monitor (turned on/off, standby)? If so, how do I do it?

The WMI (Windows Management Instrumentation) Win32_DesktopMonitor class ( contains the information I need (Availability), but the Win32_DesktopMonitor class does not update real time.

Are there any other way to get this information?

Thanks in advance.

Question by:Michael G
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
LVL 12

Expert Comment

ID: 12266053
You can handle WM_SYSCOMMAND. When monitor is being turned on/off the wParams is SC_MONITORPOWER      ...

Author Comment

by:Michael G
ID: 12269569
Thank you for your comment.

I have the following code which can tell me when powersafe gets activated, but it doesn't react if I turn off my monitor !?

unit Unit1;


  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

  TForm1 = class(TForm)
    Memo1: TMemo;

    procedure WMSysCommand(var Message : TWMSysCommand ); Message WM_SYSCOMMAND;
    { Private declarations }

    { Public declarations }

  Form1: TForm1;


{$R *.dfm}

procedure TForm1.WMSysCommand(var Message : TWMSysCommand);
// Intercept screen saver or power monitor message and do something ...
  if (Message.CmdType and $FFF0 = SC_SCREENSAVE) or
     (Message.CmdType and $FFF0 = SC_MONITORPOWER) then
     memo1.Lines.Add(datetimetostr(now)+ ': Powersafe activated or monitor power off')
  inherited; // let the message thru'
end; {WMSysCommand}

LVL 12

Expert Comment

ID: 12270926
Yep, I know about this. I couldn't make it work with monitor turned off...
Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!


Author Comment

by:Michael G
ID: 12271123
So it's not possible to detect if you turn off your monitor !?
LVL 17

Expert Comment

by:Wim ten Brink
ID: 12271996
Maybe some smarter monitors will signal the system that the monitor is turned off, but afaik, this is extremely uncommon. Many laptops will keep track of the monitor state of the LCD screen but I don't think this information is sent to the system. It's just used to turn off the monitor when you close the lid of the laptop.

Author Comment

by:Michael G
ID: 12865770
I never really solved the problem, but found a more or less working workaround.

I use a WMSysCommand, see below, to detect if powersave is activated, and then I use a global keyboard/mouse hook to detect user input that takes the monitor out of powersaving.

procedure TForm1.WMSysCommand(var Message : TWMSysCommand);
// Intercept screen saver or power monitor message and do something ...
  if  (Message.CmdType and $FFF0 = SC_SCREENSAVE) or(Message.CmdType and
$FFF0 = SC_MONITORPOWER) then begin

    memo1.Lines.Add(datetimetostr(now)+ ': powersave')
  end; {if}
  inherited; // let the message thru'
end; {WMSysCommand}

Author Comment

by:Michael G
ID: 13343683

Accepted Solution

OzzMod earned 0 total points
ID: 13369542
Closed, 500 points refunded.
Community Support Moderator (Graveyard shift)

Featured Post

On Demand Webinar - Networking for the Cloud Era

This webinar discusses:
-Common barriers companies experience when moving to the cloud
-How SD-WAN changes the way we look at networks
-Best practices customers should employ moving forward with cloud migration
-What happens behind the scenes of SteelConnect’s one-click button

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

A lot of questions regard threads in Delphi.   One of the more specific questions is how to show progress of the thread.   Updating a progressbar from inside a thread is a mistake. A solution to this would be to send a synchronized message to the…
This article explains how to create forms/units independent of other forms/units object names in a delphi project. Have you ever created a form for user input in a Delphi project and then had the need to have that same form in a other Delphi proj…
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit If you want to manage em…

710 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question