Load Revit plugin on Legacy Revit versions

[mizrachi_amir2]

Hello All,

I have a Revit plugin with 2 commands that are intended to run on Revit 2019 onward.

I am now working on the 3rd command, which is using the OST_Signage BuiltInCategory. This category is only available from Revit 2022 API.

How can I still load this whole plugin (with 3 commands) also to Revit 2019 so that the 3rd command will not be functional?

Thank you!

[mizrachi_amir2]

So - whoever tackles the same, I managed to overcome this using the preprocessor directives:

#if --> #else --> #endif

Also added this to my .csproj:

<DefineConstants>$(DefineConstants);RV$(RevitVersion)</DefineConstants>

This is what guided me:

https://levelup.gitconnected.com/multi-year-revit-addin-a-better-way-54ef441b5b4b

[nice3point]

The approach in the article above suggests creating one project, per Revit version. This is bad advice, and I don't recommend it. With Define Constants, you can support all versions of the Revit API in a single project

Recommendations:

Revit Multiversion support wiki -  https://github.com/Nice3point/RevitTemplates/wiki/Multiple-Revit-Versions

Auto Define constants generation - https://github.com/Nice3point/Revit.Build.Tasks

[mizrachi_amir2]

Thank you, @nice3point.

Actually, I used your templates so I have a single project for all versions 🙂

[nice3point · Accepted solution]

perfect) then I have good news for you, you don't need to add DefineConstants yourself. They are already contained in the templates

In your case, the only thing left to do is to wrap the code in a #if block:

#if REVIT2022_OR_GREATER
    var category = BuiltInCategory.OST_Signage;
#endif

[mizrachi_amir2]

That is just great. Thank you very much!