🚀 go-pugleaf

Hi,

I'm trying to hook a third party app to send it messages that can't be sent
accross process boundaries (f.e. messages that have pointers as
wParam/lParam, since the pointers are invalid in the other address space).

I wrote a DLL, a client app and a test server (simulating the third party
app)

The DLL exports:
SetHook(DWORD threadID)
Unhook()
and implements the hook callback function with the WH_GETMESSAGE hook type.


The client uses CreateProcess() to launch the server, then loads the DLL and
calls SetHook() with the threadID returned by CreateProcess(). I used
MessageBeep() to confirm that the DLL is loaded in the address space of the
server and that the hook callback is called for standard messages.

The problem is:
I want to send a custom message from the client to the server that should
arrive in the DLLs callback. So I defined a custom message in both the
client and the DLL:

#define HOOK_WM_TEST (WM_USER + 100)

Now I used FindWindow() in the client to get the window handle of the
servers main window. Then I did:

SendMessage(hwndServer, HOOK_WM_TEST, 0, 0);

But this messages does not arrive in the DLL callback function.

What am I doing wrong? Is WH_GETMESSAGE the correct hook type?

thanks for any idea,
Nick