We are about to start a new project using an existing SQL DB, but this project is going to need to reuse a number of core features from an existing vb6 app that uses the same database.
Two approaches I have in mind:
Approach 1:
Have the existing vb6 application be the entry point, but immediately call a .net class to present the main screen and menu. If the user needs to use a feature/form that is in vb6 then raise an event to vb6 to load that form and hide the .net side of it until it’s done.
Approach 2:
Opposite of the above, create a .net exe to be the entry point and call a vb6 dll whenever I need a vb6 feature/form.
Because of initialization that goes on in the vb6 app that makes the various features usable, I am thinking it would be less painful to do the first option. I’d like to know if there are any pros/cons I should be aware of doing it either way though.
I would definitely go with option 2:-
You should be moving towards .NET if you are not already so this way you can re-write VB6 features into .NET and when you have migrated everything you will be left with a new .NET app.
The other way round and you will always have a legacy VB6 app to convert at some point.