public void ISubtypes_Example(IFeatureClass pFeatureClass)

        {

            ISubtypes subtypes = (ISubtypes)pFeatureClass;

            if (subtypes.HasSubtype)

            {

                MessageBox.Show("有定义");

                subtypes.SubtypeFieldName = "";

            }

            else

            { 

                MessageBox.Show("没有定义");

            }

            subtypes.SubtypeFieldName = "DLBM";          

            subtypes.AddSubtype(102, "公路用地");

            subtypes.AddSubtype(104, "农村道路");

            subtypes.AddSubtype(111, "河流水面");

            subtypes.AddSubtype(117, "沟渠");

            subtypes.DefaultSubtypeCode = 102;

            subtypes.set_DefaultValue(102, "DLMC", "公路用地");

            subtypes.set_DefaultValue(104, "DLMC", "农村道路");