SetWindowsHookEx() on Windows 7

[Vasu]

Hi,

I have implemented a global keyboard hook in a 32 bit dll, using
SetWindowsHookEx(WH_KEYBOARD, lpFunction, hModule, 0) function. This
application is running without any issues on Windows XP. Recently I tested
this application on 64 bit Windows 7 operating system and I do get the
keyboard events as expected from all the Win32 applications. Surprisingly, I
am also getting the keyboard events from the 64 bit applications such as
Notepad & Wordpad. How is that possible? The document clearly says... "A
32-bit DLL cannot be injected into a 64-bit process".

BTW, I also have a global WH_SHELL hook in the same dll for which I get
events only from the 32 bit apps.

Am I missing somthing here? Any help will be appreciated.

[Nobody]

"Vasu" <Va...@discussions.microsoft.com> wrote in message
news:4B9AC5A4-2AE0-4284...@microsoft.com...

Some hooks are done as messages without loading the DLL in the target
process. If you want your 32 bit app to hook 64 bit apps, you can make a
64-Bit COM DLL and call it out of process. In this case, Windows would use
dllhost.exe to host the 64-Bit DLL, which would install the hook. I already
done that. A better solution is to make a 64-Bit version of your app. If
it's in C++, then not much changed in 64-Bit. int/long are still 32 bits,
but pointer size changed. In my case, the main app was a VB6 app, which is
32-Bit, and doesn't have a 64-Bit compiler.

[Ivo Beltchev]

Use Process Explorer to verify if your DLL is loaded in the process you
think it is. You can also check the process name/ID in your keyboard
hook (call GetModuleFileName(NULL) or GetCurrentProcessId) to verify it
really runs inside a 64-bit app.

I know that low-level keyboard hooks do run in the process that called
SetWindowsHookEx. Maybe normal keyboard hooks do too.

BTW, there are 32-bit versions of Notepad and Wordpad even on 64-bit
systems.