Using ::PostMessage and ::SendInput in a Service

To meet  the requirement for a project, I am using a windows service (made with VC6 using the old CComModule) that spawns a thread which simulates mouse events when certain conditions occur.

Now, this worked when the program was in Local Server mode and not doing any of the message handling/etc, but when I put it into Service mode and starte it, everything works right except for the mouse messages.  They don't seem to have any effect even though I receive no errors from the calls.

Any thoughts?
LVL 8
_corey_Asked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

DexstarCommented:
_corey_:

> Now, this worked when the program was in Local Server mode and not doing any
> of the message handling/etc, but when I put it into Service mode and starte
> it, everything works right except for the mouse messages.  They don't seem to
> have any effect even though I receive no errors from the calls.

What account is the service using?  In order to interact with the desktop, it is going to have to be the system service account, and you have to have the "interact with desktop" option checked in the services control panel.

If that doesn't work, then it might not be possible to have an application (directly) post messages to another user's windows.  There are ways around it though, so let me know if what I already suggested doesn't work.  :)

Hope that helps,
Dex*
0
_corey_Author Commented:
The "interact with desktop" option performs perfectly for my needs.

I just never tried to send such messages from a service before and was not sure where to look, so this really helped not waste any time :)

However, I was looking for a programming method instead of a property(which I should have), but it seems to require re-setting this option everytime you register the Service.  How can I have it defaulted, let's say after a registration of the service?
0
DexstarCommented:
You'll have to dig through the ATL code, and find out where it calls "CreateService".  The 5th parameter is "dwServiceType".  If you set the SERVICE_INTERACTIVE_PROCESS flag in that parameter, then the service will always be created as interactive.

For more information on that API, check this site:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/createservice.asp

Hope That Helps,
Dex*
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
_corey_Author Commented:
Humble pie tastes good and speeds up productivity :) Thanks for the very quick help.  A few more points for the speed?
0
DexstarCommented:
_corey_:

> Humble pie tastes good and speeds up productivity :) Thanks for the very quick
> help.  A few more points for the speed?

If you wanted to, I certainly wouldn't object!  :)

Dex*
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Development

From novice to tech pro — start learning today.