Through the Interface

Linking Circles, Part 2: Getting persistent

In the previous post we looked at some code that created chains of circles, linking them together using .NET events (a technique that can be used to maintain other types of geometric relationship, of course). In this post, we're going to extend our sample to support persistence of the link data in the AutoCAD database. Firstly, here's the updated source file. Below I've posted the code, once again with line numbers - but this time the lines that have changed or been added since the previous post are marked in red. This should highlight the modified sections of the... Read more →

Linking Circles, Part 1: Using .NET events to relate AutoCAD geometry

I received this question some time ago from Paul Richardson from CAD System Engineering: I have never been sure when to update objects programmatically. An example would be a user edits an entity that I’m tracking and I need to edit another entity in reaction to that change. Is there a standard used to cache the handle, and make the change. Doesn’t seem editing of entities should be done in the event that is watching for the change. When/how does one do it? Doesn’t seem to be any info on a standard for this. This is such an excellent... Read more →

Finding the location of a .NET module

A quick pre-Thanksgiving tip that came from an internal discussion today: how to find the location of a .NET module (meaning the currently executing assembly). Two techniques were identified: Identify the current assembly by asking where one of its types is defined Use the Assembly.GetExecutingAssembly() to get the assembly from where the current code is executing Here's the C# code showing the two techniques: using System; using System.Reflection; using Autodesk.AutoCAD.ApplicationServices; using Autodesk.AutoCAD.EditorInput; using Autodesk.AutoCAD.Runtime; namespace AssemblyLocationTest { public class AssemblyCmds { [CommandMethod("LOC")] public void GetModuleLocation() { Editor ed = Application.DocumentManager.MdiActiveDocument.Editor; // First technique Type type = typeof(AssemblyCmds); Assembly asm1... Read more →

Two methods for selecting entities at a particular location

This entry was contributed by an old friend who recently rejoined the ADN team, Jeremy Tammik. Jeremy has been in and around the Autodesk family for many years - he actually delivered the first ever ARX training in San Rafael, back when it was still called ARX - and I'm very pleased he chose to rejoin our team earlier this year. It also happens to be Jeremy's birthday this coming weekend (on Sunday 26th November), for anyone who's interested. :-) The question came in from an ADN member and revolved around the need to select objects at a particular... Read more →

Advanced jigging with AutoCAD .NET - adding keywords

This post extends the polyline-creation jig shown in the previous entry to support the use of keywords both for arc segments and for undo. A few notes: I removed the use of a separate vertex list, as it proved to be less necessary than needed This implementation supports Undo, and the toggling between Line segment and Arc segment entry Arc segments have a fixed bulge of 1.0, which is actually quite useful if drawing a cloud, but not really useful for much else. Generally the bulge should be adjusted according to the position of the cursor relative to the... Read more →

Controlling interactive polyline creation - Part 3

During the first two parts of this series we looked at different techniques for creating polylines programmatically in AutoCAD (while allowing the user to select the various vertices). In this post look at the most advanced technique yet, the use of a "Jig". A Jig is a special construct in AutoCAD that hosts an object - in our case a polyline - and feeds user input information into this object, which then determines what graphics gets displayed. This is especially useful when dealing with complex objects, such as polylines with arc segments. We're going to start with a fairly... Read more →

Controlling interactive polyline creation - Part 2

During the first part of this series, we looked at ways to drive the PLINE command while retaining (or regaining) the thread of execution in your application. During this and the next post (yes, I've decided to spread the series a little thinner :-) we're going to look at how to completely replace the user-interface to the polyline command, a very useful technique in certain situations. This post focuses on the simple use of GetPoint() to request vertex information from the user; the next post will look at a more advanced technique, the Jig. Even the "simple" user-interface implemented... Read more →

Controlling interactive polyline creation - Part 1

I received this interesting question through by email over the weekend: “How can I ask AutoCAD to let the user to draw a Polyline (just like the user pushed Polyline button) and then just after finishing drawing get the ObjectID of that entity? Is it possible?” This is a fun one, as there are a number of different approaches to take. I’m going to outline (or just go ahead and implement, depending on the complexity) the various possibilities – taking the first two today and the others in (a) subsequent post(s). The idea is to define our own command,... Read more →

Loading a partial CUI and making its toolbars visible through .NET

A discussion in the comments on this previous entry seemed worthy of turning into a post. The problem appears to be that when you load a partial CUI file into AutoCAD, by default the various resources (pull-down menus, toolbars) are not displayed. This snippet of code shows you how to both load a CUI file into AutoCAD and then loop through the toolbars in your menu-group, making them all visible. You could extend it fairly easily to add the pull-down menus contained in the CUI by using mg.Menus.InsertMenuInMenuBar(). I'm choosing to leave that as an exercise for the reader... Read more →