I am newbie in CAD programming. I am looking for API in C# or VB where I can let user to view CAD drawing such as dwg file then he can edit it like changing label names text and length of line. You can say an interactive geometry editing then once the user click save I can know all the changes made by user so that I can
save it in my database. Is it possible that ? Below is one example of my drawing
Are you talking a "general CAD API" that allows you to create a graphic editing application (i.e. invent your own "mini" CAD application, similar like AutoCAD) or you mean you want to add/enhance AutoCAD's features for doing your task more efficiently than using the AutoCAD features out of box?
For the former, I'd say, good luck if you have tons of money and big team to invest (oh, and probably very long time before you can see your product in action).
If you do not well about how to use AutoCAD, it probably is already good enough to do what your picture show. Since this forum in about AutoCAD programming, you could use AutoCAD's APIs (there are multiple sets of them: LISP, COM, .NET, ObjectARX C++) to customize AutoCAD to make the work more efficient and precise to your specific business workflow.
So, yes, if your user users use AutoCAD, you can use AutoCAD .NET API (do not waste time on VB.NET!) to make the CAD/drafting work, as your picture shows, easier/better, or difficult/worse (I mean, do not reinvent the wheel, if using AutoCAD properly can get the job done as expected).
Sorry, this forum is for AutoCAD API programing, or AutoCAD .NET API, to be specific. If you are not going to use AutoCAD, or one of its vertical (AutoCAD Plant, AutoCAD MEP...), you probably would not find meaningful response from here, I am afraid.
