[IfcLightSourcePositional.ConstantAttenuation property 常数衰减 public IfcReal ConstantAttenuation { get; set; } 也可以看看 class IfcReal class IfcLightSourcePositional 命名空间 Aspose.CAD.FileFormats.Ifc.IFC2X3.Entities 部件 Aspose.CAD]