新建shapefile,自定义字段，新加入记录

             // 生成新的shapefile
            IFields pFields  =   new  FieldsClass();
            IFieldsEdit pFieldsEdit  =  pFields  as  IFieldsEdit;
            IField pField  =   new  FieldClass();
            IFieldEdit pFieldEdit  =  pField  as  IFieldEdit;

            pFieldEdit.Name_2  =   " shape " ;
            pFieldEdit.Type_2  =  esriFieldType.esriFieldTypeGeometry;

            IGeometryDef pGeometryDef  =   new  GeometryDefClass();
            IGeometryDefEdit pGeoDefEdit  =  pGeometryDef  as  IGeometryDefEdit;
            pGeoDefEdit.GeometryType_2  =  esriGeometryType.esriGeometryPolygon;
            pGeoDefEdit.SpatialReference_2  =  axMapControl1.SpatialReference;

            pFieldEdit.GeometryDef_2  =  pGeometryDef;
            pFieldsEdit.AddField(pField);

            pField  =   new  FieldClass();
            pFieldEdit  =  pField  as  IFieldEdit;
            pFieldEdit.Length_2  =   10 ;
            pFieldEdit.Name_2  =   " CODE " ;
            pFieldEdit.AliasName_2  =   " CODE " ;
            pFieldEdit.Type_2  =  esriFieldType.esriFieldTypeString;

            pFieldsEdit.AddField(pField);

            String MapPath  =   @" E:\data\result " ;
            String LayerName  =   " AddFeature " ;

            
            IWorkspaceFactory pWsf  =   new  ShapefileWorkspaceFactory();
            IFeatureWorkspace pFws = pWsf.OpenFromFile(MapPath, 0 )  as  IFeatureWorkspace;
            IFeatureClass pFeatureClass = pFws.CreateFeatureClass(LayerName  +   " .shp " , pFields,  null ,  null , esriFeatureType.esriFTSimple,  " shape " ,  "" );

新建shapefile,自定义字段，路径自定义。
在文件里加入POLYGON，自定义字段值

            IDataset pDataset  =  (IDataset)pFeatureClass;
            pFws  =  (IFeatureWorkspace)pDataset.Workspace;
            IWorkspaceEdit pWorkspaceEdit  =  (IWorkspaceEdit)pFws;
            pWorkspaceEdit.StartEditing( true );
            pWorkspaceEdit.StartEditOperation();

            IFeatureBuffer pFeatureBuffer  =  pFeatureClass.CreateFeatureBuffer();
             // Create insert Feature Cursor using buffering = true.
            IFeatureCursor pFeatCursor  =  pFeatureClass.Insert( true );

             object  featureOID;
             // 定义新加元素的值
            pFeatureBuffer.set_Value(pFeatureBuffer.Fields.FindField( " CODE " ), " CODE " );

             // 生成Polygon**********************************************************
            IPolygon poly  =   new  PolygonClass();
            IPoint pPoint  =   new  PointClass();


             object  o  =  Type.Missing;
            IPointCollection pPc  =   new  MultipointClass();
            pPc  =  (IPointCollection)poly;

             for  ( int  i  =   0 ; i  <=   0 ; i ++  )
             {
                pPoint.PutCoords(200, 400);
                pPc.AddPoint(pPoint, ref o, ref o);

                pPoint.PutCoords(400, 400);
                pPc.AddPoint(pPoint, ref o, ref o);

                pPoint.PutCoords(400, 200);
                pPc.AddPoint(pPoint, ref o, ref o);

                pPoint.PutCoords(200, 200);
                pPc.AddPoint(pPoint, ref o, ref o);
            }

             // 生成完毕  ************************************************************

            pFeatureBuffer.Shape  =  poly;
            featureOID  =  pFeatCursor.InsertFeature(pFeatureBuffer);

             // Flush the feature cursor to the database       
             // Calling flush allows you to handle any errors at a known time rather then on the cursor destruction.
            pFeatCursor.Flush();

            pWorkspaceEdit.StopEditOperation();
            pWorkspaceEdit.StopEditing( true );

             // 释放Cursor
            System.Runtime.InteropServices.Marshal.ReleaseComObject(pFeatCursor);
            axMapControl1.AddShapeFile(MapPath,LayerName + " .shp " );