There seems to be a lot of confusion with folks about the difference between using the AutoCAD .net API vs the COM Interop API. They both hope to do the same things, but via different ways. Given a choice, I’d always recommend using the .net API because it is much more powerful. Or if you are familiar with C++ then go for ObjectARX API which gives you immense power. You may think that using .net API obviates the need to manage resources - but you’d be wrong: the .net API is simply a wrapper to the underlying unmanaged types. You have to explicitly use transactions or you have to otherwise explicitly dispose of objects after you’ve finished using them. Nevertheless, the .net API is still very good to use in certain instances.

So you’ve inserted a block reference into the model space. Very good. And you’ve decided to rotate it and move it around. Again: very good. Now you wish to programmatically place more block references, similarly rotated, but perhaps spaced some distance apart. How are you going to do this.

Wouldn’t it be handy if we could programmatically insert reference models into Tekla? Well you can now do so quite easily.

It is rare that I see masterpieces on CodeReview, but this was one that warrants incredible kudos:

We have already outlined in a previous post, what a stub is, and the benefits of unit testing.

Please do the sample questions if you really want to learn this stuff

I see this problem all too often in stack overflow: a situation where folks check for the type of a class in an if statement, and then respond accordingly. Rather than repeating myself a million times, I thought it much easier just to write a post on the subject (DRY FTW!). Anyways, this type of code (pun intended) smacks of a duck type not being identified and utilised.