[IfcDocumentElectronicFormat.MimeSubtype property MimeSubtype public IfcLabel MimeSubtype { get; set; } 也可以看看 class IfcLabel class IfcDocumentElectronicFormat 命名空间 Aspose.CAD.FileFormats.Ifc.IFC2X3.Entities 部件 Aspose.CAD]