dllmain函数怎么不一样，求解

这个dll入口怎么跟我在网上查找到的dllmain的一般形式不一样呢
// DLL 入口点
extern "C" BOOL WINAPI DllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID lpReserved)
{
#ifdef _MERGE_PROXYSTUB
    if (!PrxDllMain(hInstance, dwReason, lpReserved))
        return FALSE;
#endif
g_h_dll = hInstance;
hInstance;
    return _AtlModule.DllMain(dwReason, lpReserved); 
}#ifdef _MANAGED
#pragma managed(pop)
#endif
这是我在网上查找到的关于dllmain的解析，
这是dllmain函数的一般形式
BOOL WINAPI DllMain(
    HINSTANCE hinstDLL,  // handle to DLL module
    DWORD fdwReason,     // reason for calling function
    LPVOID lpReserved )  // reserved
{
    // Perform actions based on the reason for calling.
    switch( fdwReason ) 
    { 
        case DLL_PROCESS_ATTACH:
         // Initialize once for each new process.
         // Return FALSE to fail DLL load.
            break;        case DLL_THREAD_ATTACH:
         // Do thread-specific initialization.
            break;        case DLL_THREAD_DETACH:
         // Do thread-specific cleanup.
            break;        case DLL_PROCESS_DETACH:
         // Perform any necessary cleanup.
            break;
    }
    return TRUE;  // Successful DLL_PROCESS_ATTACH.
}