Re: ActiveX Written in VB and used in VC

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From: Alexander Nickolov (agnickolov_at_mvps.org)
Date: 10/05/04 

Date: Tue, 5 Oct 2004 09:33:54 -0700

You never executed the equivalent of VB's New, so your variables
are understandably Nothing (put in VB terms). Why are you surprised?
Read the original reply more carefully. 

-- 
=====================================
Alexander Nickolov
Microsoft MVP [VC], MCSD
email: agnickolov@mvps.org
MVP VC FAQ: http://www.mvps.org/vcfaq
=====================================
"Bradley M. Small" <BSmall@XNOSPAMXmjsi.com> wrote in message 
news:%23ypO1wtqEHA.3980@TK2MSFTNGP12.phx.gbl...
> Mark --
>
> Well I think this is going in the right direction, but not quite :(
>
> I've done this:
>
> _clsMyThingPtr oMyThing;
> _clsMyThingFactPtr oMyThingFact;
>
> oMyThingLog = oMyThingFact->CreateMyThing(
>    (BSTR *)"Text1"
>    ,(BSTR *)"Text2"
>    ,(BSTR *)"Text3"
>    ,(BSTR *)"Text4"
>    ,(BSTR *)"Text5");
>
>
> oMyThing->DoSomethingIntersting((BSTR *) "9999",(BSTR *)"Test1", (BSTR
> *)"Test2");
>
> Of course now the interface is NULL and responds with an unhandled 
> exception
> accordingly.
>
> It would appear that I am fine with making pointers to things, but what 
> they
> are pointing to is not getting instantiated so they are null pointers. I
> believe that CreateMyThing() will effectively create an instance of
> _clsMyThingPtr, but I can't seem to call it until I can instantiate one of
> them.
>
> I'm almost there I can taste it :)
>
> -- Bradley
>
> "Mark" <Mark@discussions.microsoft.com> wrote in message
> news:490BA7BD-2102-4141-84EB-50959F26920C@microsoft.com...
>> try this:
>> _clsMyThingPtr oMyThing;
>> hResult = oMyThing.CreateInstance(__uuidof(clsMyThing));
>>
>> "Bradley M. Small" wrote:
>>
>> > I have written an ActiveX DLL in visual basic. It has 2 classes in it,
> one
>> > is a factory class declared as Global multiuse and the other is public
> non
>> > creatable. In VB I
>> >
>> >     Dim oMyThing as clsMyThing
>> >     set oMyThing =  clsThingFact.CreateMyThing(parm1, parm2, parm3,
> parm4,
>> > parm5)
>> >
>> >     oMyThing.DoSomethignInteresting(parm)
>> >
>> >     set oMyThing = nothing
>> >
>> > ----
>> >
>> > This works fine, however, the program that is using it is now supposed
> to be
>> > written in Visual C++. To begin with I have not done any com stuff in
> VC,
>> > but I flipped the box in VB that makes the TLB, and put in #import
>> > "c:\mypath\mytlb.tlb" no_namespace
>> >
>> > Of couse, my simply declaring one like:
>> >
>> >     clsMyThing oMyThing;
>> >
>> > I get error C2079: 'oMyThing' uses undefined struct clsMyThing if I put
> an
>> > underscore on clsMyThing then I get that I can't instantiate an 
>> > abstract
>> > class.
>> >
>> > Anyway, if someone can just get me pointed in the right direction and
> push I
>> > would really appreciate it.
>> >
>> > Thanks
>> >
>> >
>> >
>
>