学步园

//Dll中的代码<br /> #include <windows.h></p> <p>#pragma data_seg("MyData")<br /> HINSTANCE g_hInst = NULL;<br /> #pragma data_seg()</p> <p>BOOL DllMain(HINSTANCE hDllInst,DWORD dwReason,LPVOID lpReserved)<br /> {<br /> if(DLL_PROCESS_ATTACH == dwReason)<br /> {<br /> g_hInst = hDllInst;<br /> }</p> <p> return TRUE;<br /> }</p> <p>extern "C" _declspec(dllexport) int Add(int a,int b)<br /> {<br /> return a+b;<br /> }</p> <p>//主程序加载Dll的代码<br /> #include <iostream><br /> #include <windows.h><br /> using namespace std;</p> <p>void main(int argc,TCHAR*argv[])<br /> {<br /> HINSTANCE hInst = LoadLibrary("dll1.dll");<br /> if(!hInst)<br /> {<br /> cout<<"fail"<<endl;<br /> return;<br /> }</p> <p> typedef int (*LPADD)(int,int);<br /> LPADD add = (LPADD)GetProcAddress(hInst,"Add");<br /> if(!add)<br /> {<br /> cout<<"fail2"<<endl;<br /> FreeLibrary(hInst);<br /> return;<br /> }</p> <p> cout<<add(9,8)<<endl;</p> <p> FreeLibrary(hInst);<br /> }

原因：DllMain里面的代码是在LoadLibrary的时候调用的，执行完DllMain里面的代码，如果DllMain返回true,那么LoadLibrary才会返回成功