Hey all,

I've been working with integrating AutoCAD into my VB6 Projects. I imagine that my question is not specific to AutoCAD, but that just happens to be what I'm using.

So, when I start my program, I create an instance of AutoCAD that can be accessed throughout my entire code. When the program finished, it terminates this instance.
Now, while the program is running, if I start up AutoCAD manually by opening a drawing file, it chooses the instance my VB6 Project created and makes it visible.

When I start up AutoCAD manually by double-clicking the exe, then a second (and independent) instance is generated (this is the behavior I desire!).

So... my question is this:
Is there a way my VB6 Project can hold an instance of AutoCAD that NO OTHER application can access? In other words, make the instance private to my application only?

The reason I wish to do this is because when I do open a AutoCAD drawing manually, and then close it manually, it ends the instance my VB6 Project created! Not good!
This will always make the program crash since it is referencing this terminated instance of AutoCAD. I know there are ways to check if the instance is valid, then re-create if it's not, but this puts more delay on the program (rather than loading it once and keeping it). Doing this requires error checking for each time I need to start using AutoCAD again in my application.

I know that it's probably a good idea to error-check anyways, and that the user can still terminate this instance by going to Task Manager; however, if that happens I'd rather let the program crash (this application is only going to be used internally).


I appreciate all of your help!

God Bless,
-Nick