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Hi everyone:
I need to wake a system monitor from sleep (when it was turned off automatically by OS after a certain time of inactivity). Is there any documented way to do it under Windows 7?
PS. There's a lot on this subject on this forum but most of it is stuff written for Windows XP or earlier.
Any ideas, guys???
These two ways seem working fine in my Win 7. Though I'm not sure (or better, don't care) whether these are documented/recommended for Win 7. :)
1) Set up monitor to power down in 1 min. Build the app, run it and leave the system idle. In 1 min the monitor goes off, 1 min later it wakes up.
2) Click the window, and monitor goes off. 10 seconds later it wakes up.
For the first case I tested this having the app foreground/background, and all the times it worked fine.
OK, firstly don't shoot me, I come in peace :)
What if we can totally prevent the PC from going into sleep mode, throughout the use of our application? What I'm trying to say is that you can use the SetThreadExecutionState Api with the ES_DISPLAY_REQUIRED + ES_CONTINUOUS constants to ensure that the monitor doesn't go into sleep mode while your program is running. Then, whilst exiting your app, you could use the same API only with the ES_CONTINUOUS constant
Just an idea....
Thanks. I was really amazed at how you were able to strip down the MFC code down to a bare minimum. Very professional...Quote:
Originally Posted by Igor Vartanov
As for the code to wake the screen and to turn it off, I see that you're using an older technique. But honestly, I'm really leery about using it these days. Here's the result of my tests and two very serious flaws:
(So I'm curious if you addressed it in your software if you use it there as well?)
1. I ran it on my Dell Inspiron 1750 laptop of 1.5 years with Vista Home installed and although the code to turn off the screen does the job, it works only for a short while and the screen comes back on again in a second or so. I spent a good deal of time trying to understand why this happens, and... I have no clue. But, on the side note, that OS... I don't know how is it still around...
2. I also ran it on my desktop with Windows 7 Ultimate installed and it worked as you intended except for one very essential situation when a user had a password protected screensaver. In that case your code to turn on screen did nothing. As I suspected they upped security on password protected screensaver that is now running in its own isolated session with virtually no privileges and ignores pretty much all messages that could be sent to it (as was used in almost all previous approaches of canceling it in Windows XP). Again, I tried to fix it but couldn't....
This is a very wrong approach and I hope that you don't use it in your software! Doing that will totally circumvent any power saving settings that a user might have set up. From my own experience as a software user, if I see a piece of code messing with my screen saver, or any other power saving settings, that code goes straight into trash.Quote:
Originally Posted by HanneSThEGreaT
My intentions here are just to wake the screen up to show a quick note for a user and I'm not intending to keep the screen on afterwards.
Technically, it is what exactly you're doing now: messing with the screen saver ( power saver settings ) in this situation, strange...Quote:
Originally Posted by ahmd
There are plenty of major programs from major software vendors doing exactly as I have described, an example would be most setup applications - some would keep the screen "active" until the installation has been successfully done, then only, "deactivate" the screen, and programs such as Nero and DVD fab. Seen it a million times, and counting ;)
I was just trying to help with a possible solution, that is all I was trying to do :)
Hannes
OK, Hannes, I evidently misunderstood you and I apologize. Yes, any program that performs a lengthy operation that involves a hard drive, a CD, DVD or a download must hold off computer's automatic power saving settings. But that is not what I was trying to achieve. In my case all I need is to wake up the screen (note, temporarily) to display a quick message for a user.Quote:
Originally Posted by HanneSThEGreaT
No problem at all :)
If the user has password-protected screen lock, he is likely NOT in front of his monitor. Who do you think will read your message then?Quote:
Originally Posted by ahmd
As for waking monitor up (as the subject asks for) I doubt if it matters somehow how old the techniques are. What really matters is if they work.Quote:
As for the code to wake the screen and to turn it off, I see that you're using an older technique.
Yeah, and you said nothing about the situation before. :)Quote:
it worked as you intended except for one very essential situation
Besides, showing messages on a logon screen (or unlocking the desktop, or stopping screensaver) has nothing to do with waking monitor from sleep.
Waking up the monitor just for the message seems not so good idea, if the user is there he/she will anyway wakeup the monitor by pressing keys and then automatically see the message. So I would suggest going with not allowing the power down while the program needs monitor OR letting things happen as they are happening right now.
Just tested the app with Vista Ultimate. It worked like a charm in both cases. Well, I wasn't surprised. (Seems something in your Vista does some anti-sleep thing(s) like mouse or keyboard input imitation, or you just moved your mouse unintentionally.)Quote:
1. I ran it on my Dell Inspiron 1750 laptop of 1.5 years with Vista Home installed and although the code to turn off the screen does the job, it works only for a short while and the screen comes back on again in a second or so. I spent a good deal of time trying to understand why this happens, and... I have no clue. But, on the side note, that OS... I don't know how is it still around...
There is a very special sort of software that desperately needs this kind of things: media players. ;)Quote:
This is a very wrong approach and I hope that you don't use it in your software! Doing that will totally circumvent any power saving settings that a user might have set up.
As far as I remember, it's something medical, your software. Did you think about alerting personal with audio message sent for example to bluetooth headset/speaker? Or sending text message to cellphone? Calling skype contact? These seem way more reliable in the situations when the personal may be not around, or the monitor is out of sight. :)Quote:
In my case all I need is to wake up the screen (note, temporarily) to display a quick message for a user.
Guys, I can't find a consensus here. It might be my Vista and whatever software came pre-installed with Dell that doesn't let your code, Igor work. It beats me.
As for password protected screensaver, I didn't mention that the software I need it for is a custom built energy saver that comes with my own screen saver so I have control over a message that is displayed (in the screensaver itself). The idea of waking a monitor up is to show the warning for a user that the system is about to enter a low-power state (and in some cases log off a user -- whatever they configure it for). This request came from a client so I can't really argue with it...
That might be a good idea. Thanks. I'll run it by the client and see if they want it implemented. One question though, how do you send all those notifications? Is it via some web service?Quote:
Originally Posted by Igor Vartanov
Yeah, the customers... Well, AFAIK powering monitor down looks like stopping to produce video signal. So you might dig into video drivers, how they do the things.
The bluetooth part is the simplest one. Any headset looks just like another audio output device. All you need is to ask user to configure which device should be used for notification, otherwise the default device should be used. Then you just play audio with the device selected.
The text messages: Lots of mobile operator companies have web services for relaying text messages by plain http requests. Or have SMS gateways.
Calling skype via its API is quite well documented thing, just google about it.
These are the 3 things I do to try and get the monitor/video out of a low-power state:
I haven't used this code on anything higher than XP though. If your screen saver is active, then this code may need to be run within the screen saver's context for it to work.Code:// 1st method
if (!SystemParametersInfo(SPI_SETLOWPOWERACTIVE, 0, 0, 0))
LogMessage(L"SystemParametersInfo(SPI_SETLOWPOWERACTIVE 0) failed, "
L"le = %u",
GetLastError());
// 2nd method
::SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, -1);
// 3rd method
if (!SetThreadExecutionState(ES_CONTINUOUS | ES_DISPLAY_REQUIRED |
ES_SYSTEM_REQUIRED))
LogMessage(L"SetThreadExecutionState failed, le = %u",
GetLastError());
// *** do something with screen ***
if (!SetThreadExecutionState(ES_CONTINUOUS))
LogMessage(L"SetThreadExecutionState failed, le = %u",
GetLastError());
gg
Thank you both. Very nice information.
Codeplug, I had some intense headache with HWND_BROADCAST under Vista/Windows 7. It seems that this method of broadcasting messages is very limited on those OS.
Of course, it's security enhance for Vista and Win7. No pay no gain! :)
According to my sample HWND_BROADCAST is not mandatory. The whole thing seems about to make SC_MONITORPOWER reach DefWindowProc.Quote:
Originally Posted by ahmd