Arcengine 基本操作（待更新）

        /// <summary>
        /// 删除fieldName属性值为1的弧段
        /// </summary>
        /// <param name="fieldName"></param>
        /// <param name="t"></param>
        public void DelectPolyline(string fieldName, int t)
        {

            ILayer pLayer = axMapControl1.get_Layer(0);
            IFeatureLayer pFeatureLayer = pLayer as IFeatureLayer;
            IFeatureClass pFeatureClass = pFeatureLayer.FeatureClass;

            IFields pIFields = pFeatureLayer.FeatureClass.Fields;
            int fieldIndex = pIFields.FindField(fieldName);

            var pDataset = pFeatureClass as IDataset;
            IWorkspace pWorkspace = pDataset.Workspace;
            IFeatureWorkspace pFWs = pWorkspace as IFeatureWorkspace;

            IWorkspaceEdit pWorkspaceEdit = (IWorkspaceEdit)pFWs;
            pWorkspaceEdit.StartEditing(true);
            pWorkspaceEdit.StartEditOperation();

            IFeatureCursor pEF = pFeatureLayer.Search(null, false);
            IFeature pFeatureDe = pEF.NextFeature();
            while (pFeatureDe != null)
            {
                if (Convert.ToInt32(pFeatureDe.get_Value(fieldIndex)) != t)
                {
                    pFeatureDe.Delete();
                }
                pFeatureDe = pEF.NextFeature();
            }
            pWorkspaceEdit.StopEditOperation();
            pWorkspaceEdit.StopEditing(true);
            MessageBox.Show("删除成功");
        }

///若干个线要素合并成一个
 private void MergeFeatures(List<int> OneFeatureArr,ILayer tSelectLayer)
        {
            IFeatureLayer tFeatureLayer = tSelectLayer as IFeatureLayer;
            IFeatureClass pFeatureClass = tFeatureLayer.FeatureClass;
            var pDataset = pFeatureClass as IDataset;
            IWorkspace pWorkspace = pDataset.Workspace;
            IFeatureWorkspace pFWs = pWorkspace as IFeatureWorkspace;
            
            IWorkspaceEdit pWorkspaceEdit = (IWorkspaceEdit)pFWs;
            pWorkspaceEdit.StartEditing(true);
            pWorkspaceEdit.StartEditOperation();

            IFeatureLayer pFeatureLayer = tSelectLayer as IFeatureLayer;
            IFeatureCursor pEF = pFeatureLayer.Search(null, false);
            IFeature pFeatureFirst = pEF.NextFeature();
            while (pFeatureFirst != null)
            {//找到在数组里的第一个要素
                if (pFeatureFirst.OID == OneFeatureArr[0])
                {
                    //OneFeatureArr.RemoveAt(0);//除掉第一个要素
                    break;
                }
                else
                    pFeatureFirst = pEF.NextFeature();
            }
            pEF = pFeatureLayer.Search(null, false);

            IGeometry pGeometryFirst = pFeatureFirst.Shape;
            ITopologicalOperator2 pTopOperatorFirst = (ITopologicalOperator2)pGeometryFirst;
            IRelationalOperator pRelOperatorFirst = (IRelationalOperator)pGeometryFirst;

            pTopOperatorFirst.IsKnownSimple_2 = false;
            pTopOperatorFirst.Simplify();
            pGeometryFirst.SnapToSpatialReference();

            IGeometry pGeometrySecond = null;
            IFeature pFeatureSecond = pEF.NextFeature();

            IGeometryCollection Geometrybag = new GeometryBagClass();//装geometry的袋子
            object oMissing = Type.Missing;
            while (pFeatureSecond != null)
            {
                if (OneFeatureArr.IndexOf(pFeatureSecond.OID) == -1)
                {
                    pFeatureSecond = pEF.NextFeature();
                    continue;
                }
                pGeometrySecond = pFeatureSecond.ShapeCopy;
                Geometrybag.AddGeometry(pGeometrySecond, ref oMissing, ref oMissing);//将geometry装进袋子
                //pFeatureSecond.Delete();
                pFeatureSecond = pEF.NextFeature();
            }
            IEnumGeometry tEnumGeometry = (IEnumGeometry)Geometrybag;
            pTopOperatorFirst.ConstructUnion(tEnumGeometry);

            pTopOperatorFirst.IsKnownSimple_2 = false;
            pTopOperatorFirst.Simplify();
            pFeatureFirst.Shape = pGeometryFirst;           
            pFeatureFirst.Store();            

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