arcgis engine提取面图层中心点以及面积

                    用IArea接口，里面可以取得中心点和面积

                     IArea pArea = pFeature.Shape as IArea;  

                    fieldinxet = pFeature.Fields.FindField("Area");
                    pFeature.set_Value(fieldinxet, pArea.Centroid.X);