Through the Interface

Allowing users to escape from long operations in AutoCAD .NET

The bulk of this code was donated by Virupaksha Aithal, a member of our DevTech team in India. It's fairly common for developers to want to check for user input from time to time during long operations, especially to see whether the user wants to cancel the current activity. In VB you'd use DoEvents() to enable messages to be processed by the application's message loop and in ObjectARX you'd use acedUsrBrk(). So how to do this in .NET? The answer is to use a message filter. This allows us to check on user-input events... we still call DoEvents, as... Read more →

Using the COM interface for AutoCAD objects from .NET

This question came in a couple of weeks ago from csharpbird, and I promised myself to turn it into a post: The Hatch class of the current AutoCAD version does not provide the OriginPoint property.How to get/set the OriginPoint of the Hatch object using P/Invoke? The reason I wanted to delay making an official post is that I have good news (that I couldn't talk about until the product was announced): the Autodesk.AutoCAD.DatabaseServices.Hatch object now has an Origin property in AutoCAD 2008. :-) But this does raise an interesting topic - how to get at information that isn't available... Read more →

Getting access to an entity from its handle in AutoCAD .NET

This comment came in overnight from Brian: I was hoping to work out how to get the Entity from the handle and then erase it, from your posts, I've learned a lot but not found the answer to this one yet, I still have a mountain to climb. (I'm using VB.NET, I've done it in VB6 +COM, even in Lisp but .NET ....) As it's such a good question, I'm making a post out of it... The trick is to go from a hexadecimal string to a 64-bit integer (using System.Convert.ToInt64(str,16); which specifies the string as being "base-16" or... Read more →

AutoCAD 2008 – other new APIs

In the previous two posts we looked at the new ObjectARX samples and the new .NET samples available for AutoCAD 2008. AutoCAD 2008 also exposes a number of new APIs (and enhancements to old ones) for which we don’t have new SDK samples. Take a look of the ‘Migration Guide for Applications’ for a comprehensive list of new classes and new methods and properties within classes. Check the AutoCAD Managed Class Reference for Managed equivalents. And once again - let me know if there are any of specific interest to you, and we'll see what we can do. :-)... Read more →

AutoCAD 2008 - new .NET samples

In the last post we looked at the new ObjectARX samples for AutoCAD 2008, while today we're looking at the .NET samples. In the next post we'll look at the other new APIs available with AutoCAD 2008. With the exception of custom objects, .NET now includes essentially all the functionality available in ObjectARX. While the ObjectARX samples are a good reference for .NET programmers, we’ve also bolstered our collection of .NET samples. Unfortunately, we were unable to add full .NET documentation for this release, but rest assured that our Technical Publications team is working hard on it. In the... Read more →

AutoCAD 2008 - new ObjectARX samples

The coming posts will look at the various new APIs in AutoCAD 2008. Here is the way I’ve decided to serialize the information: New ObjectARX samples - this post New .NET samples - the next post Other new APIs - the following post So this post focuses on the new C++ samples on the ObjectARX SDK for AutoCAD 2008, talking about their corresponding features and APIs. Thanks to Stephen Preston, our DevTech Americas Manager and the presenter you may seen in the previous post, for providing the bulk of this information. Annotation Scaling One of the most highly anticipated... Read more →

This one made me smile...

MSDN is a great source of information - whether when researching issues or looking for explanatory links for this blog. And I'm hoping, over time, to see more community content (as MSDN is now essentially all in wiki format), although until now I haven't come across any, I have to say. This is also something we're looking into, by the way: wikis just seem a perfect vehicle for developer documentation. But that one's still very much "in research"... Anyway - I was researching some information for my next post (which should be finished very shortly), and followed a link... Read more →

AutoCAD 2008 – 64-bit application migration

We’ve been talking to ADN members (under non-disclosure agreements) for a number of months about the 2008 family of Autodesk products, and with these products officially announced I can now talk more publicly about their features and APIs. This week I’ll focus on AutoCAD, but I plan to describe the new feature-/API-sets of other Autodesk products over the coming weeks. So what’s new in AutoCAD 2008? There are a number of very interesting new features and APIs, which I'll talk about in coming posts, but for now I want to address the more fundamental question around application migration. Firstly,... Read more →

Using .NET reflection with AutoCAD to change object properties - Part 2

In the last post we looked at some code that combined user-input from the AutoCAD command-line with .NET reflection to determine an object type, a property belonging to that type, and the value to which we want to change that property on instances of that type (phew!). Here's where we look at hooking that up with some code to work recursively through the drawing database and make the changes to the actual objects. Firstly, let's look at some C# code to check the type of an entity, and then - as appropriate - to query the property's value and... Read more →

Using .NET reflection with AutoCAD to change object properties - Part 1

I ended up having a fun weekend, in spite of the circumstances. My wife and eldest son were both sick with a cold (which, inevitably enough, I now feel I’m coming down with myself), so we mostly stayed around at home. So I got to spend a little time working on an idea that came to me after my last post. While the code I provided last time does pretty much exactly what was asked of it (allowing the person who requested it to change the colour of every entity in the modelspace – whether in nested blocks or... Read more →

Changing the colour of nested AutoCAD entities through .NET

Someone asked me earlier today how to iteratively change the color of entities inside blocks. The following code uses a recursive helper function to iterate down through the contents of a block, changing the various entities (other than block references, for which we simply recurse) to a specified colour. Here's the C# code: using Autodesk.AutoCAD.ApplicationServices; using Autodesk.AutoCAD.DatabaseServices; using Autodesk.AutoCAD.EditorInput; using Autodesk.AutoCAD.Runtime; using Autodesk.AutoCAD.Colors; namespace BlockTest { public class BlockCmds { [CommandMethod("CC")] public void ChangeColor() { Document doc = Application.DocumentManager.MdiActiveDocument; Database db = doc.Database; Editor ed = doc.Editor; PromptIntegerResult pr = ed.GetInteger( "\nEnter color index to change all entities to:... Read more →