Need help regarding interface implementation in VB

**SilentAdmirer** · 07-13-2004, 07:09 AM

Hi,
Is it possible to implement an interface in VB6 which is not directly derived from IDispatch ?
ie
Can VB6 implement an interface IDerived derived from IBase which in turn is derived from IDispatch ? If yes can you tell me how.

TIA
Satish

**deadweasel** · 07-13-2004, 10:15 PM

Ok. Wait... HUH?!?

What the heck is IDispatch, etc?

Maybe I'm just showing some n00bness, but I've never heard of that...

**SilentAdmirer** · 07-14-2004, 01:00 AM

Originally Posted by deadweasel

Ok. Wait... HUH?!?

What the heck is IDispatch, etc?

Maybe I'm just showing some n00bness, but I've never heard of that...

IDispatch: Also know as dispinterface or dual interface is required to be implemented by C++ COM objects so that the non virtual table aware lanugage like VBscript can access COM component.

**deadweasel** · 07-14-2004, 01:22 AM

Originally Posted by SilentAdmirer

IDispatch: Also know as dispinterface or dual interface is required to be implemented by C++ COM objects so that the non virtual table aware lanugage like VBscript can access COM component.

Ok. Well damn, that puts me out of the range of being able to help. Crap. You just made my eyes glaze over, and that's not always easy!

**frodobaggins** · 07-14-2004, 01:23 AM

Originally Posted by deadweasel

You just made my eyes glaze over, and that's not always easy!

Look up Fast Fourier Transform

**deadweasel** · 07-14-2004, 01:30 AM

Originally Posted by frodobaggins

Look up Fast Fourier Transform

Oh. My. GOD!!!

Geez, thanks! I was about to attribute the brain damage to the beer, but nope. Now I feel stupid. Crap.

**Ashlawn Kemling** · 07-14-2004, 04:06 AM

So... um... I say you just layout something or use DirectX. What the hell?

Tried looking some of it up... looks like more Microsoft crap... uh... DAMN.

Me brain no workies now.

**NoPistonPC** · 07-14-2004, 08:01 AM

Originally Posted by SilentAdmirer

Hi,
Is it possible to implement an interface in VB6 which is not directly derived from IDispatch ?
ie
Can VB6 implement an interface IDerived derived from IBase which in turn is derived from IDispatch ? If yes can you tell me how.

TIA
Satish

Satish, when I used to work with Visual Basic, I remember that it only allowed for one level of interface inheritance (i.e. VB-compatible interfaces must directly derive from IUnknown or IDispatch). This might have changed in VB6, but I highly doubt it.

Now is a good time to switch to C++.

**SilentAdmirer** · 07-14-2004, 09:23 AM

The only second app I have ever made in VB was the GPS test app as a lot of user in the forum are VB programmers.

Been a C++ programmer ever since I started programming

No plans to switch to any other language in the near feature...

Just wanted to know as I was designing a Plugin based system for VOICES and supporting VB is very necessary . I had a special requirement in which I would have mutliple outgoing or source interface which would be derived from a single Base interface which in turn would be derived from IDispatch. This would allow much easy use, as I would be holding the list of base interface and querying for the Derived interface only for special reason rather than holding a list of IDispatch and quering it every time.

Now the IEnumXXXX Interface makes sense, I used to always thing why MS didnot have IEnumerator as the base class for the IEnumXXXX interface when all the IEnumXXXX had the same method calls.