topic Re: C# extensions in Archicad C++ API

C# extensions

benny_ — Wed, 26 Nov 2025 10:56:38 GMT

I've been investigating whether it's possible to essentially create an extension to ArchiCAD that is written in C# by having a C++/CLI bridge from C++ to C#, but I'm a bit stuck.

I was wondering if anyone has tried this before and have any experience they can share?

Essentially, I need C++ to initialize a C# object and then provide it with callbacks to C++ so they can interoperate bidirectionally. This works fine for callbacks that return simple types, but for any complex types, it falls apart and I get a memory access violation when the C# context takes ownership of the C++/CLI initialized object through the return value of the callback function.

I've also been told to ask if there are plans to add support for C# extensions or some sort of native interop with C# in ArchiCAD?

Re: C# extensions

scottjm — Thu, 27 Nov 2025 00:59:32 GMT

That sounds like it would be extremely complicated if you did get it to work, and its likely easier to write your addon all in C++. You are not going to be able to access any of the Archicad C++ API functions directly, so you would have to have some kind of bridge for every function as you mentioned.

I would doubt very much if there would ever be any plans for direct C# support in APIs, given all the main archicad platform is written in C++.

Re: C# extensions

rwessel — Sun, 30 Nov 2025 14:20:59 GMT

No, this isn't possible. It a platform issue rather than language - C# is dependent on the .net platform and can't directly interact with anything that isn't. Otherwise, when running entirely within .net, C# and C++ (and many other languages) can interact relatively easily.