使用 __declspec(dllimport) 匯入至應用程式

#if defined(EXPORTS)
#define _class_porting_ __declspec(dllexport) /* DLL export */
#else
#define _class_porting_ __declspec(dllimport) /* DLL import */
#endif

class _class_porting_ ClassDLLPorting
{
public:
ClassDLLPorting();
~ClassDLLPorting();
};

Ref:
http://msdn2.microsoft.com/zh-tw/library/8fskxacy(VS.80).aspx