参数过滤器ElementParameterFilter——以选择一个房间内所有对象为例

 1 [TransactionAttribute(Autodesk.Revit.Attributes.TransactionMode.Manual)]
 2 public class FindFurnitureInARoom : IExternalCommand
 3 {
 4       public Result Execute(ExternalCommandData commandData, ref string messages, ElementSet elements)
 5       {
 6           try
 7           {
 8               UIApplication app = commandData.Application;
 9               Document document = app.ActiveUIDocument.Document;
10              
11               Selection sel = app.ActiveUIDocument.Selection;
12               Reference ref1 = sel.PickObject(ObjectType.Element, "Please pick a room");
13               Room room = document.GetElement(ref1) as Room;
14 
15               if (room != null)
16               {
17                   ParameterValueProvider provider = new ParameterValueProvider(new ElementId(BuiltInParameter.ELEM_ROOM_ID));
18                   FilterNumericRuleEvaluator evaluator = new FilterNumericEquals();
19 
20                   FilterElementIdRule rule = new FilterElementIdRule(provider, evaluator, room.Id);
21                   ElementParameterFilter filter = new ElementParameterFilter(rule);
22 
23                   FilteredElementCollector collector = new FilteredElementCollector(document);
24                   collector.WherePasses(filter);
25 
26                   sel = app.ActiveUIDocument.Selection;
27                   sel.Elements.Clear();
28                   foreach (Element elem in collector)
29                       sel.Elements.Add(elem);
30 
31                   TaskDialog.Show("The number", "The number of components = " + collector.Count().ToString());
32                   return Result.Succeeded;
33               }
34               else
35               {
36                   messages = "请选择一个房间！";
37                   return Result.Failed;
38               }
39           }
40           catch (Exception e)
41           {
42               messages = e.Message;
43               return Result.Failed;
44           }
45       }
46 }