Create element classes in element Datasets

Public Ifeatureclass ifeaturedataset _ createfeatureclass (ifeaturedataset featuredataset, string nameoffeatureclass ){ // This function creates a new feature class in a supplied feature dataset by building all of  // Fields from scratch. ifeatureclassdescription (or iobjectclassdescription if the table is    // Created at the workspace level) can be used to get the required fields and are used    // Get the instanceclassid and extensionclassid.  // Create new fields collection with the number of fields you plan to add. must add at least two fields  // For a feature class: Object ID and shape field. Ifields fields = New Fieldsclass (); ifieldsedit fieldsedit = (ifieldsedit) fields; fieldsedit. fieldcount_2 = 3; // Create Object ID field. Ifield fielduserdefined = New Field (); ifieldedit fieldedit = (ifieldedit) fielduserdefined; fieldedit. name_2 = "Objectid" ; Fieldedit. aliasname_2 = "Object ID" ; Fieldedit. type_2 = esrifieldtype. esrifieldtypeoid; fieldsedit. set_field (0, fielduserdefined ); // Create shape field. Fielduserdefined = New Field (); fieldedit = (ifieldedit) fielduserdefined; // Set up geometry definition for the shape field. // You do not have to set the spatial reference, as it is inherited from the feature dataset. Igeometrydef geometrydef = New Geometrydefclass (); igeometrydefedit geometrydefedit = (igeometrydefedit) geometrydef; geometrydefedit. geometrytype_2 = ESRI. ArcGIS. Geometry. esrigeometrytype. esrigeometrypolyline; // By setting the grid size to 0, you are allowing ArcGIS to determine the appropriate grid sizes for the feature class.  // If in a personal Geodatabase, the grid size is 1,000. If in a file or ArcSDE Geodatabase, the grid size  // Is based on the initial loading or inserting of features. Geometrydefedit. gridcount_2 = 1; geometrydefedit. set_gridsize (0, 0); geometrydefedit. hasm_2 = False ; Geometrydefedit. hasz_2 =False ; // Set standard field properties. Fieldedit. name_2 = "Shape" ; Fieldedit. type_2 = esrifieldtype. esrifieldtypegeometry; fieldedit. geometrydef_2 = geometrydef; fieldedit. isnullable_2 = True ; Fieldedit. required_2 = True ; Fieldsedit. set_field (1, fielduserdefined ); // Create a field of type double to hold some information for the features. Fielduserdefined = New Field (); fieldedit = (ifieldedit) fielduserdefined; fieldedit. name_2 = "Avg_income" ; Fieldedit. aliasname_2 = "Average income for 1999-2000" ; Fieldedit. editable_2 = True ; Fieldedit. isnullable_2 = False ; Fieldedit. precision_2 = 2; fieldedit. scale_2 = 5; fieldedit. type_2 = esrifieldtype. esrifieldtypedouble; fieldsedit. set_field (2, fielduserdefined ); // Create a feature class description object to use for specifying the CLSID and extclsid. Ifeatureclassdescription fcdesc = New Featureclassdescriptionclass (); iobjectclassdescription ocdesc = (iobjectclassdescription) fcdesc; Return Featuredataset. createfeatureclass (nameoffeatureclass, fields, ocdesc. instanceclsid, ocdesc. classextensionclsid, esrifeaturetype. esriftsimple, "Shape" , "" );}