Question

i have one solution file in visual studio, and i have in it two projects one for the .dll file and one other project to the .c file:

this is the .h file:

#include <windows.h>

#ifndef BHANNAN_TEST_CLASS_H_
#define BHANNAN_TEST_CLASS_H_

extern int __declspec (dllexport) Factorial(int n);

#endif 

and in .c file (of the dll ):

#include "hanan.h"
#include <stdio.h>

int Factorial(int n) {
  printf("in DLL %d \n" ,n);

  return 0;
}

now i have a loader/tester which i try from it to load the dll to hook keystrokes in notepad, just to understand the mechanism of the hooking.

this is the code of the loader:

#include <windows.h>
#include <stdio.h>

typedef int (*functor) (int);
functor funcptr =NULL;

int main () {

    HWND windowHandle;
    HINSTANCE hMod;
    HOOKPROC lpfn; 
    DWORD threadId;
    HHOOK hook;
    HMODULE myDLL = LoadLibraryW(L"dll123.dll");
    funcptr = (functor) GetProcAddress(myDLL,"Factorial");

    /// printing issues:////////////////
    printf("%d \n\r" , myDLL);
    printf("%d" , funcptr(33));
    //////////////////////////////////////

    lpfn = (HOOKPROC) funcptr;
    hMod = myDLL;
    windowHandle = FindWindow(L"Notepad",NULL);
    threadId = GetWindowThreadProcessId(windowHandle, NULL);

    hook = SetWindowsHookEx(WH_KEYBOARD,lpfn,hMod,threadId);//(WH_CBT, HookCBTProc, hInst, threadId);

    /// printing issues:
    printf("%d %d %d %d\n" , hook, WH_KEYBOARD , lpfn , hMod);
    printf("%d %d \n",threadId , windowHandle );
    getchar();
    return 0;
}

i get all the printing no zeros, which means there are no nulls (assuming notepad is running), but when i do any keystroke in notepad i get an exception right away,

using visual studio 2010 and windows 7

added exception properties:

 Exception Offset:  0006632c
  Exception Code:   c0000409
  Exception Data:   00000000

Answer 1

Just a shot in the dark, but the function that you pass to the set hook call should look like this:

LRESULT CALLBACK KeyboardProc(
  __in  int code,
  __in  WPARAM wParam,
  __in  LPARAM lParam
);

Not:
int Factorial(int n) (where are the two other params??)