SharpMap要素查詢

1、SharpMap要素查詢要素查詢 實例一：拉框查詢要素屬性 實例二：點擊查詢要素屬性 實例三：屬性查詢 代碼剖析 1、單擊事件中調用代碼 2、QueryMapByClick函數(shù) 3、ExecuteIntersectionQuery函數(shù)實例一：拉框查詢要素屬性4在 圖形的ImgMap_Click事件單擊，查詢要素屬性，所調用的代碼SharpMap.Geometries.Point ClickPnt = myMap.ImageToWorld(new System.Drawing.Point(e.X, e.Y);SharpMap.Data.FeatureDataSet dsResult; dsRes

2、ult = QueryMapByClick(ClickPnt2, ClickPnt); if (dsResult.Tables.Count 0) SessionTHETABLE = dsResult; SessionTABLENUM = 1; string strNames = ;/如何獲取選中要素的屬性數(shù)據(jù) foreach (DataRow dr in dsResult.Tables0.Rows) strNames = strNames + dr0.ToString() + ,; .1、單擊事件中調用代碼./打開顯示站點屬性的頁面if (strNames.Length 0) strNames

3、 = strNames.Substring(0, strNames.Length - 1); string strURL = StationInfo.aspx?StationName= + strNames; string strPage = window.open( + strURL + ,站點屬性,height=450,width=470,status=no,toolbar=no,menubar=no,scrollbars=yes,location=no); Response.Write(strPage); 1、單擊事件中調用代碼 /將選中的要素產(chǎn)生一個新的圖層，高亮度顯示 SharpMa

4、p.Layers.VectorLayer laySelected = new SharpMap.Layers.VectorLayer(Selection); SharpMap.Data.Providers.GeometryProvider objGeoPrd = new SharpMap.Data.Providers.GeometryProvider(dsResult.Tables0); laySelected.DataSource = objGeoPrd; laySelected.Style.Symbol = new Bitmap(HttpContext.Current.Server.Map

5、Path(App_dataStation2.bmp); laySelected.Style.SymbolScale = 0.8f; myMap.Layers.Add(laySelected);/刷新地圖 1、單擊事件中調用代碼需重點掌握 QueryMapByClick函數(shù) 如何提取查詢結果信息 foreach (DataRow dr in dsResult.Tables0.Rows)1. 如何構建新的選擇集圖層，并設置符號，高亮度顯示注意2、QueryMapByClick函數(shù)private SharpMap.Data.FeatureDataSet QueryMapByClick(SharpMa

6、p.Geometries.Point clickPoint1, SharpMap.Geometries.Point clickPoint2) SharpMap.Data.FeatureDataSet ds = new SharpMap.Data.FeatureDataSet(); SharpMap.Geometries.BoundingBox objBounds; if (clickPoint1.X != clickPoint2.X) objBounds = new SharpMap.Geometries.BoundingBox(clickPoint1.X, clickPoint1.Y, cl

7、ickPoint2.X, clickPoint2.Y); else objBounds = new SharpMap.Geometries.BoundingBox(clickPoint1.X - 0.01, clickPoint1.Y - 0.01, clickPoint1.X + 0.01, clickPoint1.Y + 0.01); 2、QueryMapByClick函數(shù). /Execute click-query on first layer in layers collection SharpMap.Layers.VectorLayer objVLyr = myMap.Layers站

8、點站點 as SharpMap.Layers.VectorLayer; if (!objVLyr.DataSource.IsOpen) objVLyr.DataSource.Open(); objVLyr.DataSource.ExecuteIntersectionQuery(objBounds, ds); if (ds.Tables.Count 0) /We have a result return ds; public void ExecuteIntersectionQuery(SharpMap.Geometries.BoundingBox box, FeatureDataSet ds)

9、FeatureDataTable fdt = new FeatureDataTable(); fdt = _features.Clone(); foreach (FeatureDataRow fdr in _features) if (fdr.Geometry.GetBoundingBox().Intersects(box) fdt.LoadDataRow(fdr.ItemArray, false); (fdt.Rowsfdt.Rows.Count - 1 as FeatureDataRow).Geometry = fdr.Geometry; ds.Tables.Add(fdt); /priv

10、ate FeatureDataTable _features;3、ExecuteIntersectionQuery函數(shù) ExecuteIntersectionQuery函數(shù)為sharpmap內(nèi)部函數(shù)，僅需了解 代碼剖析 1、單擊事件中調用代碼 2、QueryMapByClick函數(shù) 3、ExecuteIntersectionQuery函數(shù)實例二：點擊查詢要素屬性 if (rblMapTools.SelectedValue = 3) SharpMap.Geometries.Point ClickPnt = myMap.ImageToWorld(new System.Drawing.Point(e

11、.X, e.Y); SharpMap.Data.FeatureDataSet dsResult; dsResult = QueryMapByClick(ClickPnt); if (dsResult.Tables.Count 0) lblProperty.Text = ; foreach (System.Data.DataRow dr in dsResult.Tables0.Rows) lblProperty.Text += 屬性：屬性：; for (int i = 0; i dsResult.Tables0.Columns.Count; i+) lblProperty.Text += + d

12、sResult.Tables0.Columnsi.ColumnName; lblProperty.Text += + dri.ToString() + ; lblProperty.Text += ; lblProperty.Visible = true; 。 for (int i = 0; i dsResult.Tables0.Columns.Count; i+) lblProperty.Text += + dsResult.Tables0.Columnsi.ColumnName; lblProperty.Text += + dri.ToString() + ; lblProperty.Tex

13、t += ; lblProperty.Visible = true; QueryMapByClick函數(shù)函數(shù)private SharpMap.Data.FeatureDataSet QueryMapByClick(SharpMap.Geometries.Point clickPoint) SharpMap.Data.FeatureDataSet ds = new SharpMap.Data.FeatureDataSet(); SharpMap.Layers.VectorLayer objVLyr = myMap.Layers0 as SharpMap.Layers.VectorLayer; i

14、f (!objVLyr.DataSource.IsOpen) objVLyr.DataSource.Open(); SharpMap.Geometries.BoundingBox objBounds = new SharpMap.Geometries.BoundingBox(clickPoint.X - 0.01, clickPoint.Y - 0.01, clickPoint.X + 0.01, clickPoint.Y + 0.01); objVLyr.DataSource.ExecuteIntersectionQuery(objBounds, ds); / objVLyr.DataSou

15、rce.ExecuteIntersectionQuery(clickPoint, ds); if (ds.Tables.Count 0) /We have a result /Add clicked features to a new selection layer SharpMap.Layers.VectorLayer laySelected = new SharpMap.Layers.VectorLayer(Selection); laySelected.DataSource = new SharpMap.Data.Providers.GeometryProvider(ds.Tables0

16、); laySelected.Style.Fill = new System.Drawing.SolidBrush(System.Drawing.Color.Yellow); myMap.Layers.Add(laySelected); return ds; QueryMapByClick函數(shù)函數(shù)。 laySelected.DataSource = new SharpMap.Data.Providers.GeometryProvider(ds.Tables0); laySelected.Style.Fill = new System.Drawing.SolidBrush(System.Draw

17、ing.Color.Yellow); myMap.Layers.Add(laySelected); return ds; 為sharpMap內(nèi)部函數(shù)，與上同3、ExecuteIntersectionQuery函數(shù) 依據(jù)查詢條件，查詢要素 獲取該要素的屬性 高亮度顯示該要素實例三：屬性查詢private void QueryFeatureByAttri(string sLayerName, string sFieldName, string sFieldValue) SharpMap.Data.FeatureDataSet ds = new SharpMap.Data.FeatureDataSe

18、t(); SharpMap.Layers.VectorLayer objVLyr = myMap.LayerssLayerName as SharpMap.Layers.VectorLayer; if (objVLyr != null) long count = objVLyr.DataSource.GetFeatureCount(); if (!objVLyr.DataSource.IsOpen) objVLyr.DataSource.Open(); SharpMap.Data.FeatureDataRow tempFeat; for (uint i = 0; i count; i+) te

19、mpFeat = objVLyr.DataSource.GetFeature(i); lblProperty.Text = tempFeatsFieldName.ToString();/判斷字段值是否相等，若相等，則查詢到該要素 if (tempFeatsFieldName.ToString() = sFieldValue) /高亮度顯示該要素 SharpMap.Data.FeatureDataTable tempTable = new SharpMap.Data.FeatureDataTable(); tempTable = (tempFeat.Table as SharpMap.Data.

20、FeatureDataTable).Clone(); tempTable.LoadDataRow(tempFeat.ItemArray, false); FeatureDataRow tempRow; tempRow = tempTable.RowstempTable.Rows.Count - 1 as FeatureDataRow; tempRow.Geometry = tempFeat.Geometry; SharpMap.Layers.VectorLayer laySelected = new SharpMap.Layers.VectorLayer(Selection); laySele

21、cted.DataSource = new SharpMap.Data.Providers.GeometryProvider(tempTable); laySelected.Style.Fill = new System.Drawing.SolidBrush(System.Drawing.Color.Yellow); myMap.Layers.Add(laySelected); /顯示該要素的其他屬性 lblProperty.Text = ; lblProperty.Text += 屬性：; for (int j = 0; j tempFeat.Table.Columns.Count; j+)

22、 / lblProperty.Text += tempFeat.Table.Columnsi.ColumnName+ +tempFeati.ToString()+ lblProperty.Text += + tempFeat.Table.Columnsj.ColumnName; lblProperty.Text += + tempFeatj.ToString() + ; lblProperty.Visible = true; break; /判斷字段值是否相等，若相等，則查詢到該要素 if (tempFeatsFieldName.ToString() = sFieldValue) /高亮度顯示

23、該要素 SharpMap.Data.FeatureDataTable tempTable = new SharpMap.Data.FeatureDataTable(); tempTable = (tempFeat.Table as SharpMap.Data.FeatureDataTable).Clone(); tempTable.LoadDataRow(tempFeat.ItemArray, false); FeatureDataRow tempRow; tempRow = tempTable.RowstempTable.Rows.Count - 1 as FeatureDataRow; t

24、empRow.Geometry = tempFeat.Geometry; SharpMap.Layers.VectorLayer laySelected = new SharpMap.Layers.VectorLayer(Selection); laySelected.DataSource = new SharpMap.Data.Providers.GeometryProvider(tempTable); laySelected.Style.Fill = new System.Drawing.SolidBrush(System.Drawing.Color.Yellow); myMap.Layers.Add(laySelected); /顯示該要素的其他屬性 lblProperty.Text = ; lblProperty.Text += 屬性：; for (int j = 0; j tempFeat.Table.Columns.Count; j+) / lbl