BuildingCoder.CmdCollectorPerformance.GetStairsOnLevel C# (CSharp) Метод

        FilteredElementCollector GetStairsOnLevel(
            Document doc,
            Level level)
        {
            ElementId id = level.Id;

              BuiltInCategory bic
            = BuiltInCategory.OST_Stairs;

              FilteredElementCollector collector
            = new FilteredElementCollector( doc );

              collector.OfCategory( bic );

              // explicit iteration and manual
              // checking of a property:

              List<Element> stairs = new List<Element>();

              foreach( Element e in collector )
              {
            if( e.LevelId.Equals( id ) )
            {
              stairs.Add( e );
            }
              }

              // using LINQ:

              IEnumerable<Element> stairsOnLevelLinq =
            from e in collector
            where e.LevelId.Equals( id )
            select e;

              // using an anonymous method:

              IEnumerable<Element> stairsOnLevelAnon =
            collector.Where<Element>( e
              => e.LevelId.Equals( id ) );

              // using a parameter filter:

              BuiltInParameter bip
            = BuiltInParameter.STAIRS_BASE_LEVEL_PARAM;

              ParameterValueProvider provider
            = new ParameterValueProvider(
              new ElementId( bip ) );

              FilterNumericRuleEvaluator evaluator
            = new FilterNumericEquals();

              FilterRule rule = new FilterElementIdRule(
            provider, evaluator, id );

              ElementParameterFilter filter
            = new ElementParameterFilter( rule );

              return collector.WherePasses( filter );
        }