IPoilygon转IPoint

  private void 河流面转点ToolStripMenuItem_Click(object sender, EventArgs e)

         {

             ESRI.ArcGIS.Geodatabase.IWorkspaceFactory wsf = new ESRI.ArcGIS.DataSourcesFile.ShapefileWorkspaceFactory();

             IWorkspace ws = wsf.OpenFromFile(@"F:\1-水利项目\安徽水利\0826处理", );

             IFeatureClass autoStation = (ws as IFeatureWorkspace).OpenFeatureClass("淮河干流面");

             IFeatureClass f1 = (ws as IFeatureWorkspace).OpenFeatureClass("河道范围点");

             int num = autoStation.FeatureCount(null);

             int k = ;

             string file = @"F:\1-水利项目\安徽水利\ANSL20120808\ANSL\OutPut\淮河干流\hedaopolygon.txt";

             if (File.Exists(file))

             {

                 File.Delete(file);

             }

             StreamWriter writer = new StreamWriter(file, true);

             string strpt = "";

             for (int i = ; i < num; i++)

             {

                 IPolygon pg = autoStation.GetFeature(i).Shape as IPolygon;

                 IPointCollection ptc = pg as IPointCollection;

                 for (int j = ; j < ptc.PointCount; j++)

                 {

                     IPoint pt = ptc.get_Point(j);

                     k++;

                     IFeature fea = f1.CreateFeature();

                     fea.Shape = pt;

                     fea.set_Value(fea.Fields.FindField("Id"), k);

                     fea.set_Value(fea.Fields.FindField("longi"), pt.X);

                     fea.set_Value(fea.Fields.FindField("latit"), pt.Y);

                     fea.Store();

                     strpt=strpt+pt.X+","+pt.Y+","+"0,";

                 }

                 strpt = strpt + ptc.get_Point().X + "，" + ptc.get_Point().Y + "," + "0,";

             }

             writer.Write(strpt);

             writer.Close();

         }

IPolygon转换为IPoint，且点的坐标值写入txt中。