Re: Strane linker errors when exporting DLL that uses ADO

From:
"Alex Blekhman" <tkfx.REMOVE@yahoo.com>
Newsgroups:
microsoft.public.vc.language
Date:
Thu, 24 Apr 2008 11:20:34 +0300
Message-ID:
<uFFZTQepIHA.1240@TK2MSFTNGP02.phx.gbl>
<muybluie@hotmail.com> wrote:

In a different DLL, I link with the the LIB for the above code,
and attempt to use 'B'. However, I get an 'unresolved external'
linker error for 'B::method'. The weird thing is that if I
change the method to not be virtual, or if I change the
parameter to not be a RecordsetPtr, the code links successfully.
It seems like the combination of a virtual method and an ADO
recordset does not work.
What gives?


Did you introduce the MSADO namespace (or whataever name is
generated by the #import directive) in the different DLL? Try to
use fully qualified name for ADO classes (i.e., with namespace):

class __declspec(dllexport) A
{
    //All kinds of stuff
    virtual method( MSADO::_RecordsetPtr rs );
};

class __dclspec(dllexport) B : public A
{
    //override
    virtual method( MSADO::_RecordsetPtr rs );
};

Also, I assume you have a proper macro instead of the
"__dclspec(dllexport)" specifier, which expands either to
"dllexport" or "dllimport" according to the project settings.

Alex

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