【225】ArcEngine 實現要素添加 & 刪除

參考：ArcGIS Engine效率探究——要素的添加和刪除、屬性的讀取和更新

刪除要素

                //添加圖層，顯示在最上面
                axMapControl1.AddShapeFile(@"D:\01-業務工作\08-綜合業務平台\綜合業務平台數據\船載", "cjsj.shp");
                //刪除 shapefile 中的要素
                //獲取第一個圖層
                ILayer pLayer = axMapControl1.get_Layer(0);
                //以矢量圖層的形式獲取
                IFeatureLayer pFLayer = pLayer as IFeatureLayer;
                //獲取要素集
                IFeatureClass pFC = pFLayer.FeatureClass;
                //查詢全部要素
                IFeatureCursor pFCursor = pFC.Search(null, false);
                IFeature pfeature = pFCursor.NextFeature();
                //遍歷所有要素，並刪除
                while (pfeature != null)
                {
                    pfeature.Delete();
                    pfeature = pFCursor.NextFeature();
                }

添加要素，dtzh 為 DataTable 對象

                for (int i = 0; i < dtzh.Rows.Count; i++)
                {
                    //定義一個點，並加入經緯度
                    IPoint pPoint = new PointClass();
                    double lon = Double.Parse(dtzh.Rows[i]["經度"].ToString());
                    double lat = Double.Parse(dtzh.Rows[i]["緯度"].ToString());
                    pPoint.PutCoords(lon, lat);

                    //將點添加到要素集中，並存儲
                    IFeature pFeature = pFC.CreateFeature();
                    pFeature.Shape = pPoint;
                    pFeature.Store();

                    //獲取索引值
                    int i_id = pFC.FindField("Id");
                    int i_time = pFC.FindField("Time");
                    int i_cjsj = pFC.FindField("采集時間");
                    int i_lon = pFC.FindField("經度");
                    int i_lat = pFC.FindField("緯度");
                    int i_fo = pFC.FindField("Fo");
                    int i_fm = pFC.FindField("Fm");
                    int i_fv = pFC.FindField("Fv");
                    int i_bv = pFC.FindField("BV");
                    int i_yield = pFC.FindField("Yield");

                    //為要素添加屬性值
                    pFeature.set_Value(i_id, i);
                    pFeature.set_Value(i_time, dtzh.Rows[i]["Time"].ToString());
                    pFeature.set_Value(i_cjsj, dtzh.Rows[i]["采集時間"].ToString());
                    pFeature.set_Value(i_lon, Double.Parse(dtzh.Rows[i]["經度"].ToString()));
                    pFeature.set_Value(i_lat, Double.Parse(dtzh.Rows[i]["緯度"].ToString()));
                    pFeature.set_Value(i_fo, Int32.Parse(dtzh.Rows[i]["Fo"].ToString()));
                    pFeature.set_Value(i_fm, Int32.Parse(dtzh.Rows[i]["Fm"].ToString()));
                    pFeature.set_Value(i_fv, Int32.Parse(dtzh.Rows[i]["Fv"].ToString()));
                    pFeature.set_Value(i_bv, Int32.Parse(dtzh.Rows[i]["Blank Value"].ToString()));
                    pFeature.set_Value(i_yield, dtzh.Rows[i]["Yield"].ToString());

                    pFeature.Store();
                }

顯示地圖經緯度坐標

        private void axMapControl1_OnMouseMove(object sender, IMapControlEvents2_OnMouseMoveEvent e)
        {
            tssl_lonlat.Text = String.Format("經緯度：東經{0:0.000}°  北緯{1:0.000}°", e.mapX, e.mapY);
            tssl_lonlat.Visible = true;
        }