how do I export symbols for MFC executable to create a .NET dll reference?

From:

"William Johnston" <williamj@tenbase2.com>

Newsgroups:

microsoft.public.vc.language

Date:

Mon, 02 Jul 2007 13:10:08 -0400

Message-ID:

<1183396208_2474@news.newsville.com>

Hello.

I was sent a VC++ 6.0 project and was told to export symbols so that I may call the routines from a .NET project.

How do I export typedef functions, from an MFC app, that ultimately call LoadLibrary for unmanaged code?

I built the project with clr enabled and as a dll. However, no symbols were shown for dumpin and an .exe file was always created. I also attempted to include _declspec(export) for the typedef function DIS_EXTRACT, but this did not work!

Here is some sample code:

void CVobExtractDlg::OnButtonExtract()
{
    //only checking
    if ( gLibDVD != NULL )
    {
        FreeLibrary( gLibDVD );
    }

    gLibDVD = LoadLibrary( "vobextractlib.dll" ) ;

    if ( gLibDVD == NULL )
    {
        AfxMessageBox( "VOBEXTRACTLIB.DLL is not loaded." );
    }

    if ( gLibDVD != NULL )
    {
        char szVOB1[260]; szVOB1[0] = '\0';
...

        GetDlgItem( IDC_EDIT_V1 )->GetWindowText( szVOB1, 260 );
        GetDlgItem( IDC_EDIT_V2 )->GetWindowText( szVOB2, 260 );
...

        DIS_EXTRACT Call_Extract = (DIS_EXTRACT)GetProcAddress( gLibDVD, "fuExtract" );
        Call_Extract( szVOB1, szVOB2, szVOB3, szVOB4, szVOB5, szVOB6, szVOB7, szVOB8, szVOB9, szVOBOut,
                      szTimeStart, szTimeEnd, nScanAll, nExtract, GetSafeHwnd() );
    }
}

Even if I could export this function, how could this function be used? (Would I need to recreate the GUI data?!?)

As of now, I simply created a C++ .NET wrapper class for use with a Visual C# 2005 console application and used the LoadLibary and typedef function invocation code above. However, I was told to use a valid HWND object for the final parameter to the Call_Extract function! It is NULL since the .NET app is a console application.

Thanks,
William Johnston