i am trying to get the material information (Id) from a family but within revit and not the family, using the GetMaterialId method: https://www.revitapidocs.com/2020/6011352e-151b-b8ac-14cc-45970f2fe5ad.htm
But the output is a empty list. It should be the ID of Beton - C30/37 (Concrete).
Also when i use the ID of the element(family) for the GetMaterialId() method i get a warning:
The actual goal is to change the material of the family. Maybe someone has any ideas how to do that?
Thanks for the help!