how to get the HWND from the windows on the "locked screen"

[Krzysztof Gorgolewski]

hi there, i'm trying to get the window handle from the only window, when my windows is locked. it has the "Computer Locked" title, so first i tried FindWindow(NULL, "Computer Locked"), but nothing. then i tried GetWindow(GetDesktopWindow(), GW_HWNDFIRST), because it's the (hopefully) one and only active window on the locked screen. but nothing. and i also tried WindowFromPoint with the mid point of my screen, because the "computer locked" window is centered an the screen. but no luck at all. sooo, anyone an idea or hint, how to get this _hard to get_ window handle? regards ps: google is also not giving any useful results

[Iain Clarke Warrior Programmer]

I would try using Spy++, which comes with visual studio (at least it did - I assume it still does with newer stuff than I have), and see if you can find your desired window. Maybe it has a special window class name you can look for? And even if it is the only application you can see, I bet there are a loads of top level windows you can't see. Most tray apps will have an invisible one for getting messages at the very least. Iain.

[SandipG]

Hi Iain, How can we use SPY++ after the computer screen in locked?? Can you please elaborate.. I tried to get the window handle but no success :( Thanks!!

Regards, Sandip.

[David Crow]

Krzysztof Gorgolewski wrote:

...so first i tried FindWindow(NULL, "Computer Locked"), but nothing.

What does that function return? If NULL, have you tried calling GetLastError()? Are you sure that is the exact name of the window being sought?

"Love people and use things, not love things and use people." - Unknown

"The brick walls are there for a reason...to stop the people who don't want it badly enough." - Randy Pausch

[Roger Stoltz]

Krzysztof Gorgolewski wrote:

i'm trying to get the window handle from the only window, when my windows is locked.

So you want to get a handle to the window that is displayed when the user session is locked... Why? In order to do what? :suss: From a technical aspect I doubt this is even possible, but here are my thoughts... From that screen you can switch user through "Fast User Switching", which means that you create or active another desktop. This suggests to me that this window doesn't even belong to the session your application is running in and this is probably also why ::FindWindow() cannot find the window. If you want to know when the session gets locked you can register for session notifications with WTSRegisterSessionNotification() and process the WM_WTSSESSION_CHANGE message.

"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown

[SimonSays]

You pretty much don't. The security screen is on a different desktop (read up on Windows Desktop objects) which is completely inaccessible to normal code.

[Krzysztof Gorgolewski]

thanks for your thoughts. hm... so it's not possible because of security reasons? not nice to hear... i already got the message, when the screen/computer is locked (after the lock i'm changing the wallpaper and additionally wanted to move the f§%*$ng ... ehm ... nice "computer locked" window). ok, GetLastError i will have to check later. and the thing with a different desktop was/is also in my mind. maybe it's possible to find/enumerate through the available desktops and have a look for my desired window (if the security allows it : ) so long

[Krzysztof Gorgolewski]

oh yes: http://msdn.microsoft.com/en-us/library/ms682573(VS.85).aspx => "... Applications cannot access the Winlogon desktop ..." maybe i can change the access rights for my "default" desktop/program somehow to get to this "winlogon" desktop's content?!? criss

[Krzysztof Gorgolewski]

one more thought in the morning: once i used an application called Active Desktop Calendar. and it was displaying its calendar/todo/etc also on the locked screen. soo that means, if this application is able to access the Winlogon desktop, why should i not be able? regards

[SandipG]

Does this[^] help?

Regards, Sandip.

[Krzysztof Gorgolewski]

still i didn't had time to try anything new, but i let you know. regards