BuildingCoder.CmdCollectorPerformance.f1 C# (CSharp) Метод

        void f1( Document doc )
        {
            FilteredElementCollector collector
            = new FilteredElementCollector( doc );

              ICollection<Element> levels
            = collector.OfClass( typeof( Level ) )
              .ToElements();

              for( int i = 0; i < levels.Count; i++ )
              {
            ElementId levelId = levels.ElementAt( i ).Id;

            ElementLevelFilter levelFilter
              = new ElementLevelFilter( levelId );

            collector = new FilteredElementCollector( doc );

            ICollection<Element> allOnLevel
              = collector.WherePasses( levelFilter )
            .ToElements();

            // . . .
              }
        }