Hide Revit group via API

Joe Ye

Through Revit UI command, we can hide group by picking it and click the hide command like other elements. Howerver I cannot hide group via API.

Here is the DevelopSharp code I used.
        public void hidegroup()
        {
            Document doc = this.ActiveUIDocument.Document;
            Selection sel = this.ActiveUIDocument.Selection;           
            Reference ref1 = sel.PickObject(ObjectType.Element,"Please pick a group");
            Element elem = doc.GetElement(ref1);
           
            IList<ElementId> lists = new List<ElementId>();
            lists.Add(elem.Id);
           
            Transaction trans = new Transaction(doc);
            trans.Start("hidegroup");
            doc.ActiveView.HideElements(lists);
            trans.Commit ();
          
        }

Launch the command, pick any group,  error occurs. The error message is :
Revit failed to execute hidegroup.
A problem has been detected.

Then how can we hide a group? Any tricks?

Solution

Groups cannot be hidden or overridde like ordinary elements. In order to hide a group, we need to hide the element set in that group by HideElements() method. The good aspect is that we can hide part of a group.

Here is the code to hide the whole group.

public void hidegroup()
{
    Document doc = this.ActiveUIDocument.Document;

    Selection sel = this.ActiveUIDocument.Selection;   

    Reference ref1 = sel.PickObject(ObjectType.Element,"Please pick a group");

    Element elem = doc.GetElement(ref1);

    IList<ElementId> lists = new List<ElementId>();

    Group g = elem as Group;

    IList<ElementId> ids = g.GetMemberIds();

    Transaction trans = new Transaction(doc);

    trans.Start("hidegroup");

    this.ActiveUIDocument.ActiveView.HideElements(ids);

    trans.Commit ();

}