BuildingCoder.CmdListAllRooms.Execute C# (CSharp) Method

        public Result Execute(
            ExternalCommandData commandData,
            ref string message,
            ElementSet elements)
        {
            UIApplication uiapp = commandData.Application;
              UIDocument uidoc = uiapp.ActiveUIDocument;
              Application app = uiapp.Application;
              Document doc = uidoc.Document;

              // Filtering for Room elements throws an exception:
              // Input type is of an element type that exists in
              // the API, but not in Revit's native object model.
              // Try using Autodesk.Revit.DB.SpatialElement
              // instead, and then postprocessing the results to
              // find the elements of interest.

              //FilteredElementCollector a
              //  = new FilteredElementCollector( doc )
              //    .OfClass( typeof( Room ) );

              // Solution using SpatialElement and then
              // checking for Room type

              //FilteredElementCollector a
              //  = new FilteredElementCollector( doc )
              //    .OfClass( typeof( SpatialElement ) );

              //foreach( SpatialElement e in a )
              //{
              //  Room room = e as Room;

              //  if( null != room )
              //  {
              //    ListRoomData( room );
              //  }
              //}

              // Improvement suggested by
              // Victor Chekalin using LINQ

              // http://thebuildingcoder.typepad.com/blog/2011/11/accessing-room-data.html
              // ?cid=6a00e553e168978833017c3690489f970b#comment-6a00e553e168978833017c3690489f970b
              // --> version 2013.0.100.2

              //FilteredElementCollector collector
              //  = new FilteredElementCollector( doc );

              //var rooms = collector
              //  .OfClass( typeof( SpatialElement ) )
              //  .OfType<Room>();

              //FilteredElementCollector collector
              //  = new FilteredElementCollector( doc );

              //var rooms = collector
              //  .OfClass( typeof( SpatialElement ) )
              //  .OfType<Room>();

              FilteredElementCollector collector
            = new FilteredElementCollector( doc )
              .OfClass( typeof( SpatialElement ) );

              IEnumerable<Element> rooms = collector
            .Where<Element>( e => e is Room );

              foreach( Room room in rooms )
              {
            ListRoomData( room );
              }

              return Result.Succeeded;
        }