Didn't work on Windows 7, but it works on Windows 8 dll

Question

I have two DLL files, A and B.

A needs B for setWindowsHookEx().

I use:

LoadLibrary(L"C:\\Sources\\TestDLL.dll") and GetProcAddress(hDll, "GetMsgProc")

When I try to run my program on Windows 7, GetProcAddress(hDll, "GetMsgProc") returns an error.

GetLastError() returns 122, but I think it not a good error code.

When I run my program on Windows 8 everything works.

When I change the function call in GetProcAddress(hDll, "foo")

typedef void(*foo)(); just creates message box

Everything works on Windows 7 and Windows 8.

I think my problem is __stdcal l, but I don't find the solution.

DLL file A

typedef void(*foo)();

typedef LRESULT(_stdcall *LPGetMsgProc)(int nCode, WPARAM wParam, LPARAM lParam);


#define NOM_CLASSE_JAVA_TEST "Lcom/XXX/controller/fonctions/Fonctions;"

JNIEXPORT jboolean JNICALL Java_com_XXX_system_Jni_getVeille
    (JNIEnv *env, jclass)
{
    {
        HINSTANCE hDll = (HINSTANCE)LoadLibrary(L"C:\\Sources\\TestDLL.dll");
        CString str1("it ok");

        if (!hDll)
        {
            CString str5("error1");
            CString str4(GetLastError().ToString());
            MessageBox(NULL, str4, str5, MB_ICONERROR);
            return -1;
        }

        LPGetMsgProc pfnProc = (LPGetMsgProc)GetProcAddress(hDll, "GetMsgProc");

        if (!pfnProc)
        {
            CString str5("error2");
            CString str4(GetLastError().ToString());
            MessageBox(NULL, str4, str5, MB_ICONERROR);
            FreeLibrary(hDll);
            return -1;
        }

        // Setup global hook
        HHOOK hHook = SetWindowsHookEx(WH_GETMESSAGE, (HOOKPROC)pfnProc, hDll, 0);
        if (!hHook)
        {
            CString str5("hookeroor");
            CString str4(GetLastError().ToString());
            MessageBox(NULL, str4, str5, MB_ICONERROR);
            FreeLibrary(hDll);
            return -1;
        }

        while (TRUE)
        {
            // Check to see if any messages are waiting in the queue
            while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
            {
                // Translate the message and dispatch it to WindowProc()
                TranslateMessage(&msg);
                DispatchMessage(&msg);
            }

            // If the message is WM_QUIT, exit the while loop
            if (msg.message == WM_QUIT)
                break;
        }
        return true;
    }
}

DLL file B

#define WIN32_LEAN_AND_MEAN

#include <windows.h>
#include <stdio.h>
#include <string>
#include <conio.h>
#include <tchar.h>
#include <boost/interprocess/file_mapping.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include <iostream>
#include <fstream>
#include <cstddef>
#include <cstdio>    //std::remove
#include <vector>
#pragma comment(lib, "user32.lib")


extern "C" _declspec(dllexport) void foo(void)
{
    MessageBox(NULL, (LPCTSTR)"ok", (LPCTSTR)"ok", MB_ICONERROR);
}

//============================================================================
extern "C"
{
    _declspec(dllexport) LRESULT _stdcall GetMsgProc(int nCode, WPARAM wParam, LPARAM lParam)
    {
        MessageBox(NULL, (LPCTSTR)"ok", (LPCTSTR)"ok", MB_ICONERROR);
        nCode = 0;
        wParam = NULL;
        lParam = NULL;
    }
}
//============================================================================

I run my program on Windows 8 64 bit and Windows 7 32 bit.

I run Dependency Walker and I found the name GetProcAddress(hDll, "_GetMsgProc@12"); , but my program won't work.

Answer 1

这样，代码或编译器必须具有Windows 8和与Windows 7或更早版本不兼容的最新代码。