//exportFun.def 文件名随意
EXPORT
add @1              //格式  函数名 @编号 <NONAME> 函数名应该就是导出的含书名，PE工具看过能对上号。可以在getprocaddress里直接用这名字  
sub @2 NONAME
//myDll.cpp
int add(int a,int b)
{
return a+b;
}

int sub(int a,int b)
{
  return a-b;  
}
//入口函数，文件名随意xx.cpp
#include <Windows.h>

BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
                     )
{
    switch (ul_reason_for_call)
    {//下边几个*发挥
    case DLL_PROCESS_ATTACH:
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    case DLL_PROCESS_DETACH:
        break;
    }
    return TRUE;
}