revit api 实现过滤墙图元并选中

 public IList<Element> findElementsByCategory(Autodesk.Revit.UI.UIApplication aApp,
     Document aDoc, BuiltInCategory ACategory)
 {
     FilteredElementCollector collector = new FilteredElementCollector(aDoc).OfCategory(
         ACategory).WhereElementIsNotElementType();

     IList<Element> oList = new List<Element>();
     foreach (Element ent in collector)
         oList.Add(ent);
     return oList;
 }

 Document doc = commandData.Application.ActiveUIDocument.Document;
 Selection sel = commandData.Application.ActiveUIDocument.Selection;
 IList<Element> oList = findElementsByCategory(commandData.Application,
     doc, BuiltInCategory.OST_Walls);
 ICollection<ElementId> oSelSet = new List<ElementId>();
 foreach (Element ent in oList)
     oSelSet.Add(ent.Id);
 sel.SetElementIds(oSelSet);