Thread: C++ Global Keyboard Hook

Hmmm.
If you scour msn for SetWindowsHookEx I think you'll find plenty of information.
I haven't used hooks very much so I don't remember how to do it.
Just note that global hooks must be placed in a dll and will also slow the system down somewhat.

Originally Posted by Elysia

Hmmm.
If you travel msn for SetWindowsHookEx I think you'll find plenty of information.
I haven't used hooks very much so I don't remember how to do it.
Just note that global hooks must be placed in a dll and will also slow the system down somewhat.

They must be placed in a dll? So I compile a dll in C++ and declare it in another program?

I've read somewhere that you can use Sleep(50); to speed it up a bit.

EDIT: I searched around and found out the easy way to set up a global keyboard hook, now how would I make it display messages? And what is the different between a global and a thread hook?

Thank you.

You will have to create both a dll and an application (exe) to make it work.
Then link that dll you your application. Tutorials on that? Hmmm. There was some at the board before. Let's see if I can find it.
And using Sleep with hooks is generally a bad idea.
The problem is that Windows will call your program code for every keyboard message that gets passed around in the system. And your program must respond to them and pass on the hook and message to its next recipient.
So sleeping is bad idea there.

Ah, here it is.
This applies mostly to Visual Studio:
http://cboard.cprogramming.com/showthread.php?t=98191

Quote from MSDN:

The global hooks are a shared resource, and installing one affects all applications in the same desktop as the calling thread. All global hook functions must be in libraries. Global hooks should be restricted to special-purpose applications or to use as a development aid during application debugging. Libraries that no longer need a hook should remove its hook procedure.

So essentially, global affects all applications in the system - it's global.