topic Re: Remove Group with Revit API in Revit API Forum

Remove Group with Revit API

george1985 — Fri, 09 Dec 2022 12:37:05 GMT

Does anyone know how to remove all Model Groups from Revit's Project Browser, with Revit API?

There is a solution from 2011 by removing the GroupType - which does not work anymore (when I run the code, the Groups are still there in the Project Browser).

I would be very grateful for any kind of help.

Re: Remove Group with Revit API

naveen.kumar.t — Fri, 09 Dec 2022 13:40:47 GMT

Hi @george1985 ,

I am not able to reproduce the issue.

The code is working fine on my end.

FilteredElementCollector collector = new FilteredElementCollector(doc).OfClass(typeof(GroupType)); Transaction transaction1 = new Transaction(doc); transaction1.Start("Delete Group Type"); doc.Delete(collector.ToElementIds()); transaction1.Commit();

Before

After

Re: Remove Group with Revit API

george1985 — Fri, 09 Dec 2022 17:39:03 GMT

Hi @naveen.kumar.t

Thank you very much for the quick reply.

I was not precise enough, I apologize for that.
I am trying to delete unused Groups from Project Browser, as well. Unsused Groups are those whose elements have been ungrouped (so they no more contain elements, but they are still present in the Project Browser):

If I run your code, only the used Groups (those that have not been 'Ungrouped') will be removed from the Project Browser.
Unused are not returned in 'collector' variable.

Do you have some idea how to remove these unused groups from the Project Browser?

Re: Remove Group with Revit API

naveen.kumar.t — Sun, 11 Dec 2022 13:08:41 GMT

Hi @george1985 ,

Try using this below code

FilteredElementCollector collector = new FilteredElementCollector(doc).OfClass(typeof(GroupType)); IList<ElementId> unusedGroups= new List<ElementId>(); foreach(Element e in collector) { GroupType group = e as GroupType; GroupSet groupSet = group.Groups; if(groupSet.Size==0) { unusedGroups.Add(group.Id); } } Transaction actrans = new Transaction(doc); actrans.Start("Delete unused Groups"); doc.Delete(unusedGroups); actrans.Commit();

Re: Remove Group with Revit API

george1985 — Sun, 11 Dec 2022 16:49:31 GMT

Works perfectly.
Thank you very much for the fantastic support @naveen.kumar.t !