[IfcMaterialLayerSetUsage.ReferenceExtent property 参考范围 public IfcPositiveLengthMeasure ReferenceExtent { get; set; } 也可以看看 class IfcPositiveLengthMeasure class IfcMaterialLayerSetUsage 命名空间 Aspose.CAD.FileFormats.Ifc.IFC4.Entities 部件 Aspose.CAD]
