Difference between VBA and VB.Net?

Hi All,

I have a simple question that may take more than a simple answer. What is the difference between programming for AutoCAD in VBA and in VB.Net?

I have done a fair amount of programming in VL and i'm starting to work in VBA, and today my IS department has given me a gift of an unopened VB.Net (Standard) package.

Should i use this or continue to work with the VBA that comes with AutoCAD? Advantages? Disadvantages? I don't even know what questions to ask? What is this '.net' environment?

TIA,
Sal

 

AutoCAD VBA is accessible only from a running instance of AutoCAD while
..NET is a standalone environment. Grossly oversimplifying, .NET is far
more capable than VBA but it's also more complex. Thanks to the new,
native .NET APIs for AutoCAD, .NET also enjoys better access to
AutoCAD's drawing databases.

 

Thanks Frank,

If i can press you to further elaborate, what do you mean by 'more capable' and 'better access to AutoCAD's drawing databases'?

I have heard about the 'more complex' issue, but was told it would be a long time, if ever, before .net replaced VBA. What is your take on this?

Since i'm only getting started with VBA in Acad and could go either way at this point, do you have any recommendations or suggestions? I have written VB stand-alones but nothing in VBA.

Sal

 

Hi Sal,

I would say the only advantage of VBA is sample code, help files and a
higher level of expertise in the NG to help you.

The decision is mostly a psychological one - do you enjoy being at the
cutting edge or not?

--


Laurie Comerford
CADApps
www.cadapps.com.au

capable' and 'better access to AutoCAD's drawing databases'?

long time, if ever, before .net replaced VBA. What is your take on this?

this point, do you have any recommendations or suggestions? I have written
VB stand-alones but nothing in VBA.

 

Like all .NET languages, VB.NET has a wealth of ready-to-use code in the
form of the .NET framework so you spend the bulk of your time leveraging
that functionality rather than writing it.

As for better access to AutoCAD, the managed libraries are thin wrappers
around a subset of the ObjectARX API so you can do things not available
to VB or VBA programmers.

VBA will be with us for quite some time, yes. However, in and of itself,
that means very little. That's like saying DOS is still around. While
true, that does not speak to whether your needs can be met with a
particular set of tools.

If you know VB, you know VBA. I guess what it boils down to is the kind
of work you'll be doing. If it's all macros, VBA is more than
sufficient. When it comes to working with technologies like data access,
XML and web services (to name a few), VB.NET is a far better choice.
Especially when you consider it can do everything VBA can do.

 

Though I am very familiar with both - VBA and VB.NET, I never worked with VB.NET in an AutoCAD context.

Just out of curiosity,
How is it done?

 

The COM model is still the same but you have to deal with interop issues
like marshaling and casting.

The new managed libraries offer additional tools primarily aimed at
drawing database manipulation.

 

Hi Frank,

Thanks again for taking the time to elaborate. As always, your experience and knowledge are only exceeded by your willingness to help others. And speaking for 'other', we appreciate it.

Sal

 

Net is not fully supported by AutoCAD. I am designing a program to work with Architectural desktop using vb.net and have had some problems from time to time. There is one part of the program that I had to do in VBA and then execute from my program. There are definite advantages working with vb.net, but I have also found some major problems to work through.

I found that it is better to use the type objects that start with "I" most of the time. They do not work when you are trying to run events off an AutoCAD object, but they best when trying to change properties of objects, particularly w/ Architectural Desktop. For example instead of using AcadLine I use IAcadLine. The "I" stands for an interface object.

I hope this has been helpful

 

Matt,
What were you able to accomplish with VBA that you couldn't accomplish with
VB.NET? Just curious. Thanks.
--
Bobby C. Jones

with Architectural desktop using vb.net and have had some problems from time
to time. There is one part of the program that I had to do in VBA and then
execute from my program. There are definite advantages working with vb.net,
but I have also found some major problems to work through.

of the time. They do not work when you are trying to run events off an
AutoCAD object, but they best when trying to change properties of objects,
particularly w/ Architectural Desktop. For example instead of using
AcadLine I use IAcadLine. The "I" stands for an interface object.

 

Anchoring a door to a wall in architectural desktop 2004. Here is the code:

Dim Drawing As AcadDocument
Set Drawing = Application.ActiveDocument
Dim Door As AcadObject
Dim Anchor As New AecAnchorOpeningBaseToWall

Dim tempob As AcadSelectionSet
Set tempob = Drawing.SelectionSets.Item("Openingtemp")
Dim walltemp As AecWall
Set walltemp = tempob.Item(0)
Set Door = tempob.Item(1)
Drawing.SelectionSets.Item("Openingtemp").Delete
Anchor.Reference = walltemp
Door.AttachAnchor Anchor

In VB.net you cannot get AecAnchorOpeningBaseToWall to initialize properly. Every time you set the anchor.reference it comes up w/ saying "Reference not set to an instance of an object". If you use IAecAnchorOpeningBaseToWall (the interface object), you cannot call the New on it, so it doesn't initialize properly. If anyone has come up with a way to do it in VB.net, I would love to hear about it.

Matt

 

Concrete classes typically have a name in the form <interface>Class. If
the Aec object library follows the same convention, something like this
might work:

Dim Anchor As IAecAnchorOpeningBaseToWall = New
AecAnchorOpeningBaseToWallClass();

 

If you are still interested in this topic, I wanted to let you know that I tried that and it didn't work. Thank you for the tip though because I have found it usefull in other situations. If you have anything else that would be helpful, I would appreciate it. Thanks again.