Hey all, I'm got some decently complex code here, using a dll to set up a global mouse hook(windows stuff). Anyway, I am getting this error:
C:/Users/JohnJr/Desktop/My Programs/Hooks/Test/main.cpp.text$_ZN9MouseHook11SetFunctionEPc[MouseHook::SetFunction(char*)]+0x55): undefined reference to `__imp__MProc@12'
I'm not quite sure why it isn't recognizing the MProc. Here's my code, and I have linked the .a file to my project.
Program main.cpp
Code:
#include <windows.h>
#include <iostream>
#include "C:\Users\JohnJr\Desktop\My Programs\Hooks\MouseHook.h"
#include "C:\Users\JohnJr\Desktop\My Programs\Hooks\HookProcs\main.h"
/* Declare Windows procedure */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
/* Make the class name into a global variable */
char szClassName[ ] = "CodeBlocksWindowsApp";
extern int mouseX;
extern int mouseY;
MouseHook* h = 0;
int WINAPI WinMain (HINSTANCE hThisInstance,
HINSTANCE hPrevInstance,
LPSTR lpszArgument,
int nCmdShow)
{
HWND hwnd; /* This is the handle for our window */
MSG messages; /* Here messages to the application are saved */
WNDCLASSEX wincl; /* Data structure for the windowclass */
/* The Window structure */
wincl.hInstance = hThisInstance;
wincl.lpszClassName = szClassName;
wincl.lpfnWndProc = WindowProcedure; /* This function is called by windows */
wincl.style = CS_DBLCLKS; /* Catch double-clicks */
wincl.cbSize = sizeof (WNDCLASSEX);
/* Use default icon and mouse-pointer */
wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
wincl.lpszMenuName = NULL; /* No menu */
wincl.cbClsExtra = 0; /* No extra bytes after the window class */
wincl.cbWndExtra = 0; /* structure or the window instance */
/* Use Windows's default colour as the background of the window */
wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;
/* Register the window class, and if it fails quit the program */
if (!RegisterClassEx (&wincl))
return 0;
/* The class is registered, let's create the program*/
hwnd = CreateWindowEx (
0, /* Extended possibilites for variation */
szClassName, /* Classname */
"Code::Blocks Template Windows App", /* Title Text */
WS_OVERLAPPEDWINDOW, /* default window */
CW_USEDEFAULT, /* Windows decides the position */
CW_USEDEFAULT, /* where the window ends up on the screen */
544, /* The programs width */
375, /* and height in pixels */
HWND_DESKTOP, /* The window is a child-window to desktop */
NULL, /* No menu */
hThisInstance, /* Program Instance handler */
NULL /* No Window Creation data */
);
/* Make the window visible on the screen */
ShowWindow (hwnd, nCmdShow);
h = new MouseHook();
h->SetFunction("C:/Users/JohnJr/Desktop/My Programs/Hooks/HookProcs/bin/Debug/HookProcs.dll");
/* Run the message loop. It will run until GetMessage() returns 0 */
while (GetMessage (&messages, NULL, 0, 0))
{
/* Translate virtual-key messages into character messages */
TranslateMessage(&messages);
std::cout << mouseX;
/* Send message to WindowProcedure */
DispatchMessage(&messages);
}
/* The program return-value is 0 - The value that PostQuitMessage() gave */
return messages.wParam;
}
/* This function is called by the Windows function DispatchMessage() */
LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message) /* handle the messages */
{
case WM_DESTROY:
PostQuitMessage (0); /* send a WM_QUIT to the message queue */
break;
case WM_KEYUP:
if(wParam == VK_SPACE)
h->Set();
else
h->UnSet();
break;
default: /* for messages that we don't deal with */
return DefWindowProc (hwnd, message, wParam, lParam);
}
return 0;
}
MouseHook.h(The interface class)
Code:
/****************************
MouseHookClass
Author: John M
*****************************/
#ifndef MHookClass
#define MHookClass
#include <windows.h>
#include <iostream>
#include "C:\Users\JohnJr\Desktop\My Programs\Hooks\HookProcs\main.h"
class MouseHook
{
private:
LRESULT CALLBACK (*MouseProc)(int nCode, WPARAM wParam, LPARAM lParam); //MouseProc pointer
HINSTANCE hLib;
HHOOK hook; //handle to hook
public:
MouseHook()
{
hook = NULL;
hLib = NULL;
}
~MouseHook()
{
if(MouseProc != 0)
UnSet();
}
bool SetFunction(char* dll)
{
hLib=LoadLibrary(dll);
if(hLib==NULL)
{
std::cout << "Unable to load library!" << std::endl;
return false;
}
MouseProc = &MProc; << Error call is right here!
return true;
}
bool Set()
{
if(hLib == NULL)
return false;
if(hook != NULL)
return false;
hook = SetWindowsHookEx(
WH_MOUSE,
(HOOKPROC)MouseProc,
hLib,
0);
std::cout << "Hook is set";
if(hook != NULL)
return true;
return false;
}
bool UnSet()
{
if (hook == NULL)
return false;
hook = NULL;
return UnhookWindowsHookEx(hook);
}
};
#endif
The dll's main.h
Code:
#ifndef __MAIN_H__
#define __MAIN_H__
#include <windows.h>
/* To use this exported function of dll, include this header
* in your project.
*/
#ifdef BUILD_DLL
#define DLL_EXPORT __declspec(dllexport)
#else
#define DLL_EXPORT __declspec(dllimport)
#endif
#ifdef __cplusplus
extern "C"
{
#endif
DLL_EXPORT LRESULT CALLBACK MProc(int nCode, WPARAM wParam, LPARAM lParam);
int mouseX;
int mouseY;
#ifdef __cplusplus
}
#endif
#endif // __MAIN_H__
Then the main.cpp of the dll
Code:
#include "main.h"
//May need to place in shared segment
int mouseX = 0;
int mouseY = 0;
// a sample exported function
DLL_EXPORT LRESULT CALLBACK MProc(int nCode, WPARAM wParam, LPARAM lParam)
{
if(nCode < 0)
return CallNextHookEx(NULL, nCode, wParam, lParam);
//Check wParam here
if (wParam == WM_LBUTTONUP)
{
MOUSEHOOKSTRUCT * hHook = (MOUSEHOOKSTRUCT*)lParam;
mouseX = hHook->pt.x;
mouseY = hHook->pt.y;
}
return CallNextHookEx(NULL, nCode, wParam, lParam);
}
BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
{
switch (fdwReason)
{
case DLL_PROCESS_ATTACH:
// attach to process
// return FALSE to fail DLL load
break;
case DLL_PROCESS_DETACH:
// detach from process
break;
case DLL_THREAD_ATTACH:
// attach to thread
break;
case DLL_THREAD_DETACH:
// detach from thread
break;
}
return TRUE; // succesful
}
Please, if anyone can explain why the MProc isn't being recognized, I'm fairly new to DLL's and this is actually my first attempt alone. Thanks in advance!!
Solved thanks to arpsmack.. Thanks!