I'm trying to find a way of having "plug-ins" in a VB application, so that
at runtime we can load all the modules in a plugin directory and populate a
menu in the main app, from where we can open the GUI of each plugin. We also
want to be able to call standard functions that we put in each module and
get messages back.
First thought is a directory of DLLs and use LoadLibrary to get each DLL at
runtime after getting a directory listing. However, VB can only seem to make
"ActiveX DLLs" and as far as I can see each of these only has four standard
DLL functions- DLLGetClassObject, DLLRegisterServer, DLLUnregisterServer and
DLLCanUnloadNow. I started digging into this to see if they could be called
on the fly, rather than adding them to the "References" l
ist at design time,
but rapidly decided it would take too long to figure out.
So I wondered anyone here had any thoughts. Can VB be made to make a
"normal" DLL
rather than an ActiveX one? Is it possible to dynamically load .ocx files
into a running VB app on the fly and pop up a form with one on?
Another way to do it is to have the "plugins" as seperate executables and
communicate between them. Doable, and perhaps preferable to writing the
plugins in C++ (not decided), but messy.
--
Dr. Craig Graham, Software Engineer
Advanced Analysis and Integration Limited, UK
