Re: DLL export

From:

Dan Bloomquist <public21@lakeweb.com>

Newsgroups:

microsoft.public.vc.mfc,microsoft.public.vc.language

Date:

Thu, 27 Mar 2008 01:05:57 GMT

Message-ID:

<VpCGj.631$NU2.32@news01.roc.ny>

worlman385@yahoo.com wrote:

for creating a DLL in VC++ 2005, what's the following do? is it a must
have?

#ifdef _USRDLL
#define EPGLIB_API __declspec( dllexport )
#else /* _USRDLL */
#define EPGLIB_API __declspec( dllimport )
#endif /* _USRDLL */
======================

That is fine. I don't know if it is more official to use:
#ifdef HECRAFT_DLL_COMPILE
#define HECRAFT_EXPORT AFX_CLASS_EXPORT
#else
#define HECRAFT_EXPORT AFX_CLASS_IMPORT
#endif

for each function that' call by DLL user, I must add

PROJECTName_API + return type + PASCAL + functionName like follows?
why related to PSCAL??

EPGLIB_API BOOL PASCAL CreateEPGLibInstance();
EPGLIB_API HRESULT PASCAL LoadXMLData(LPCTSTR tszXMLFileName);
EPGLIB_API HRESULT PASCAL PostSoapRequest();

The PASCAL is unnecessary. My docs say it is obsolete.

class CEPGLibApp : public CWinApp
{
public:
    CEPGLibApp();
    HRESULT LoadXMLData(LPCTSTR tszXMLFileName);

// Overrides
public:
    virtual BOOL InitInstance();
    virtual int ExitInstance();

    DECLARE_MESSAGE_MAP()
};

EPGLIB_API BOOL PASCAL CreateEPGLibInstance();
EPGLIB_API HRESULT PASCAL LoadXMLData(LPCTSTR tszXMLFileName);
EPGLIB_API HRESULT PASCAL PostSoapRequest();

See TN033 about exporting class members. This won't link as the members
look to be declared as globals.

You would
class A
{
AFX_EXT_CLASS void Member( );
};

If you don't want to export the whole class.

But there is more to it as you are creating a CWinApp. Are you sure that
is what you want to do?

Best, Dan.