[IfcRepresentationItem.LayerAssignments property 层分配 public IfcCollection<IfcPresentationLayerAssignment> LayerAssignments { get; } 也可以看看 class IfcCollection<T> class IfcPresentationLayerAssignment class IfcRepresentationItem 命名空间 Aspose.CAD.FileFormats.Ifc.IFC2X3.Entities 部件 Aspose.CAD]