How to write a simple Keyboard hook

[trix]

Great tutorial, well written!

[Bruno]

Why "KeyboardProc@12" and not "KeyboardProc" ?

TY

[Sokman]

Gratz on your nice article Kekke, I'll talk to ya soon

Sokz

[Bruno]

But, how to communicate with your program telling that a key was pressed?

[lukasina]

amazing tutorial, big gratz, I 'm waiting for next

[adnimo]

Why "KeyboardProc@12" and not "KeyboardProc" ?

TY

Normally in std calls windows symbols require the "@" and the amount of bytes the parameters take (so imagine you have one byte param and 2 int params, that gives you 9, thus FunctionName@9)

[Ecrislee]

This won't work. Windows applications usually have several threads. You need to hook thread that has created main window. With this method you don't know what thread you have found. You know only that thread is connected with your process id. Finding right thread is simpler than you think. You used GetWindowThreadProcessId() function and you hasn't looked at msdn?

Return Value

DWORD

The return value is the identifier of the thread that created the window.

That's right thread .

Now all should be like that.
[code=cpp]
#include <windows.h>

int main(int argc, char *argv[])
{
DWORD dwThreadId = 0;
DWORD dwProcessId = 0;
HWND hTibiaWnd = 0;
HINSTANCE hDll = 0;
HOOKPROC KeyboardProc = 0;
HHOOK hHook = 0;

hTibiaWnd = FindWindow(0, "Tibia");
if (!hTibiaWnd)
{
// Do something
return 0;
}

dwThreadId = GetWindowThreadProcessId(hTibiaWnd, &dwProcessId);
if (!dwThreadId)
{
// Do something
return 0;
}

hDll = LoadLibrary("Keyboardhooktest.dll");
if (!hDll)
{
// Do something
return 0;
}

KeyboardProc = reinterpret_cast<HOOKPROC>(GetProcAddress(hDll, "KeyboardProc@12"));
if (!KeyboardProc)
{
// Do something
return 0;
}

hHook = SetWindowsHookEx(WH_KEYBOARD, KeyboardProc, hDll, dwThreadId);
if (!hHook)
{
// Do something
return 0;
}

system("pause");

UnhookWindowsHookEx(hHook);
FreeLibrary(hDll);

return 0;
}
[/code]
This is simpler, faster and wil work .

If somebody has problem with "KeyboardProc@12" try "_KeyboardProc@12". Anyway look at exports library file. There you will find name of your function.