Through the Interface

Blocking AutoCAD commands from .NET

Thanks to Viru Aithal from the DevTech team in India team for this idea (he reminded me of this technique in a recent ADN support request he handled). A quick disclaimer: the technique shown in this entry could really confuse your users, if implemented with inadequate care. Please use it for good, not evil. I talked at some length in previous posts about MDI in AutoCAD, and how various commands lock documents when they need to work on them. When commands try to lock (or unlock) a document, an event gets fired. You can respond to this event in... Read more →

Configuring AutoCAD's use of the .NET Framework via acad.exe.config

Thanks to Fernando Malard for suggesting part of this topic in response to an issue he submitted through ADN support. Windows applications that make use of the .NET Framework can be configured via a “.config” XML file found in their executable’s main directory (for more specifics, please see this MSDN article). In AutoCAD’s case, this file is called acad.exe.config, and is found in c:\Program Files\AutoCAD 2007 (for instance). The default contents of this file for AutoCAD 2007 are:

A colleague of mine in one of our Engineering teams just shared this tip that I'm in turn sharing with you... I was implementing an override of the abstract class Autodesk.AutoCAD.DatabaseServices.DwgFiler, which has about 40 abstract functions that have to be overridden. Since there are no header files in C#, I couldn’t just cut and paste all the signatures as a template, like I would in C++. As I was manually typing in each signature, I noticed that Intellisense was keeping track of which signatures I had already accounted for. I thought… if it can do that, why can’t... Read more →

This entry completes the series of posts about per-document data. Here are the previous entries: Some background to AutoCAD's MDI implementation and per-document data Per-document data in ObjectARX Per-document data in AutoCAD .NET applications - Part 1 Document.UserData Now let's take a look at a second technique in .NET for storing transient (non-persisted) data with an AutoCAD document, the UserData property. The managed framework for AutoCAD associates a hash table with each document, which can be accessed using the UserData property. Hash tables are a great way to store and access data quickly: each object you store in a... Read more →

The last few posts have focused on the history of MDI in AutoCAD and how to store per-document data in ObjectARX applications. Now let’s take a look at what can be done for AutoCAD .NET applications... There are two main approaches for storing per-document data in managed applications loaded into AutoCAD – I’ll take a look at the first in this entry and tackle the second technique next time. Define commands as instance members of a class In managed applications you can declare instance or static methods. Static methods are those specified as “static” in C# or “Shared” in... Read more →

As discussed in the previous post, AutoCAD is now largely an MDI application, and this can have an impact on the design of applications. Let’s talk about the theoretical issue with migrating applications into a multiple-document environment. We used to highlight this nicely, back when we first started talking about MDI in AutoCAD 2000. We demonstrated a simple ObjectARX application that defined an alternative RECTANGLE command. The code used in the demo can still be found in the ObjectARX SDK, under samples\editor\rect. The original command - as defined in the badrectang.cpp file – makes use of static member variables... Read more →

Thanks once again to all of you who posted your congratulations on Zephyr’s birth. I’m now getting back into the swing of things after my paternity leave, and I hope this is me restarting regular posts to this blog. I’m actually feeling quite energized (although it’s probably nervous energy from sleep-deprivation :-) and have a number of topics I’d like to discuss over the coming weeks. First up is per-document data. Before talking about how best to segment data on a per-document basis, it’s definitely worth talking about some of the history of this area – with respect to... Read more →

A quick Visual Studio tip - automatically implement interfaces in C#

A colleague of mine in one of our Engineering teams just shared this tip that I'm in turn sharing with you... I was implementing an override of the abstract class Autodesk.AutoCAD.DatabaseServices.DwgFiler, which has about 40 abstract functions that have to be overridden. Since there are no header files in C#, I couldn’t just cut and paste all the signatures as a template, like I would in C++. As I was manually typing in each signature, I noticed that Intellisense was keeping track of which signatures I had already accounted for. I thought… if it can do that, why can’t... Read more →

Per-document data in AutoCAD .NET applications - Part 2

This entry completes the series of posts about per-document data. Here are the previous entries: Some background to AutoCAD's MDI implementation and per-document data Per-document data in ObjectARX Per-document data in AutoCAD .NET applications - Part 1 Document.UserData Now let's take a look at a second technique in .NET for storing transient (non-persisted) data with an AutoCAD document, the UserData property. The managed framework for AutoCAD associates a hash table with each document, which can be accessed using the UserData property. Hash tables are a great way to store and access data quickly: each object you store in a... Read more →

Per-document data in AutoCAD .NET applications - Part 1

The last few posts have focused on the history of MDI in AutoCAD and how to store per-document data in ObjectARX applications. Now let’s take a look at what can be done for AutoCAD .NET applications... There are two main approaches for storing per-document data in managed applications loaded into AutoCAD – I’ll take a look at the first in this entry and tackle the second technique next time. Define commands as instance members of a class In managed applications you can declare instance or static methods. Static methods are those specified as “static” in C# or “Shared” in... Read more →

Per-document data in ObjectARX

As discussed in the previous post, AutoCAD is now largely an MDI application, and this can have an impact on the design of applications. Let’s talk about the theoretical issue with migrating applications into a multiple-document environment. We used to highlight this nicely, back when we first started talking about MDI in AutoCAD 2000. We demonstrated a simple ObjectARX application that defined an alternative RECTANGLE command. The code used in the demo can still be found in the ObjectARX SDK, under samples\editor\rect. The original command - as defined in the badrectang.cpp file – makes use of static member variables... Read more →

Some background to AutoCAD's MDI implementation and per-document data

Thanks once again to all of you who posted your congratulations on Zephyr’s birth. I’m now getting back into the swing of things after my paternity leave, and I hope this is me restarting regular posts to this blog. I’m actually feeling quite energized (although it’s probably nervous energy from sleep-deprivation :-) and have a number of topics I’d like to discuss over the coming weeks. First up is per-document data. Before talking about how best to segment data on a per-document basis, it’s definitely worth talking about some of the history of this area – with respect to... Read more →