Events from .net DLL not reaching VB6 app

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Todd Beaulieu - 18 Nov 2005 11:56 GMT

I have a VB6 app that instantiates a .net DLL class, sinking the events. It
never receives the events, however.

This very code has been working for almost one year on a number of servers.
The problem server is a new box that we're trying to bring up with our
applications installed. I get no errors. I can call the .net DLL. It does
it's work and then raises the event, but the VB6 app never receives it. I've
put logging in all over the place, so I know the .net DLL is executing the
code to raise the event.

Now, I know I've seen this very issue before, but I can't figure out how to
solve it. I could have sworn that the fix was to re-register (regasm) the
.net DLLs in the correct order (implemented interfaces first, then main
DLL), but nothing has helped.

Note that I'm having another, seemingly-related issue with this same box
(see post entittled "At witt's end!!!! QueryInterface for interface xxx
failed.").

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Dmytro Lapshyn [MVP] - 18 Nov 2005 12:51 GMT

Todd,

Will you be able to check if the .NET's assembly type library is properly
registered on that box?
I remember that one might need to register the type library separately for
.NET COM-visible assemblies.

Signature

Sincerely,
Dmytro Lapshyn [Visual Developer - Visual C# MVP]

>I have a VB6 app that instantiates a .net DLL class, sinking the events. It
> never receives the events, however.
[quoted text clipped - 17 lines]
> (see post entittled "At witt's end!!!! QueryInterface for interface xxx
> failed.").

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Todd Beaulieu - 18 Nov 2005 13:32 GMT

Thank you for helping.

Just to be thorough (yes, I have done this a number of times), I just
repeated the entire exercise. I unregistered the TLB with regserver and
unregistered the DLL with regasm.

I then copied the exact version that's running on another box and used
regasm with /tlb option.

Same deal. It invokes, but I'm not receiving it's com events, as I am on the
other box. UGH.

> Todd,
>
> Will you be able to check if the .NET's assembly type library is properly
> registered on that box?
> I remember that one might need to register the type library separately for
> .NET COM-visible assemblies.

Reply to this Message

Dmytro Lapshyn [MVP] - 18 Nov 2005 15:22 GMT

If you open the DLL in OLE View (View Typelib...), can you see the source
interface for the events?

Signature

Sincerely,
Dmytro Lapshyn [Visual Developer - Visual C# MVP]

> Thank you for helping.
>
[quoted text clipped - 16 lines]
>> for
>> .NET COM-visible assemblies.

Reply to this Message

Todd Beaulieu - 21 Nov 2005 12:07 GMT

Yeah, I can see the events. The DLL is working fine on my machine and on a
set of production servers already in service. The coding must be sound and
correct, since it's all working. It's got to be environmental.

> If you open the DLL in OLE View (View Typelib...), can you see the source
> interface for the events?
[quoted text clipped - 19 lines]
> >> for
> >> .NET COM-visible assemblies.

Reply to this Message

Dmytro Lapshyn [MVP] - 23 Nov 2005 09:50 GMT

Well, I remember I have had problems with the /tlb option. So what I would
recommend to try first is to export a separate tlb file and register it with
a third-party tool such as regtlib.exe

Signature

Sincerely,
Dmytro Lapshyn [Visual Developer - Visual C# MVP]

> Yeah, I can see the events. The DLL is working fine on my machine and on a
> set of production servers already in service. The coding must be sound and
[quoted text clipped - 28 lines]
>> >> for
>> >> .NET COM-visible assemblies.

Reply to this Message

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Events from .net DLL not reaching VB6 app

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