開源SharpMap實例講解(三)剖析課件

1、開源SharpMap實例講解（三）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：屬性查詢實例一：拉框查詢要素屬性代碼剖析1、單擊事件中調用代碼2、QueryMapByClick函數(shù)3、ExecuteIntersectionQuery函數(shù)41、單擊事件中調用代碼在 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 dsResu

2、lt; dsResult = 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)

3、 strNames = 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

4、示 SharpMap.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.S

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

6、ometries.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, clickP

7、oint2.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站點 as

8、 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; 3、ExecuteIntersectionQuery函數(shù) public void ExecuteIntersectionQuery(SharpMap.Geometries.BoundingBox b

9、ox, FeatureDataSet ds) 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

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

11、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：; for (int i = 0; i dsResult.Tables0.Columns.Count; i+) lblProperty.Text += + dsResult.Table

12、s0.Columnsi.ColumnName; lblProperty.Text += + dri.ToString() + ; lblProperty.Text += ; lblProperty.Visible = true; 1、單擊事件中調用代碼在 圖形的ImgMap_Click事件單擊，查詢要素屬性，所調用的代碼。 for (int i = 0; i dsResult.Tables0.Columns.Count; i+) lblProperty.Text += + dsResult.Tables0.Columnsi.ColumnName; lblProperty.Text += + d

13、ri.ToString() + ; lblProperty.Text += ; lblProperty.Visible = true; 1、單擊事件中調用代碼在 圖形的ImgMap_Click事件單擊，查詢要素屬性，所調用的代碼2、QueryMapByClick函數(shù)private SharpMap.Data.FeatureDataSet QueryMapByClick(SharpMap.Geometries.Point clickPoint) SharpMap.Data.FeatureDataSet ds = new SharpMap.Data.FeatureDataSet(); SharpM

14、ap.Layers.VectorLayer objVLyr = myMap.Layers0 as SharpMap.Layers.VectorLayer; if (!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)

15、; objVLyr.DataSource.ExecuteIntersectionQuery(objBounds, ds); / objVLyr.DataSource.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); l

16、aySelected.DataSource = new SharpMap.Data.Providers.GeometryProvider(ds.Tables0); laySelected.Style.Fill = new System.Drawing.SolidBrush(System.Drawing.Color.Yellow); myMap.Layers.Add(laySelected); return ds; 2、QueryMapByClick函數(shù)。 laySelected.DataSource = new SharpMap.Data.Providers.GeometryProvider(

17、ds.Tables0); laySelected.Style.Fill = new System.Drawing.SolidBrush(System.Drawing.Color.Yellow); myMap.Layers.Add(laySelected); return ds; 3、ExecuteIntersectionQuery函數(shù) 為sharpMap內部函數(shù)，與上同實例三：屬性查詢依據(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private void QueryFeatureByAttri(string sLayerName, string sFieldName, string s

18、FieldValue) SharpMap.Data.FeatureDataSet ds = new SharpMap.Data.FeatureDataSet(); SharpMap.Layers.VectorLayer objVLyr = myMap.LayerssLayerName as SharpMap.Layers.VectorLayer; if (objVLyr != null) long count = objVLyr.DataSource.GetFeatureCount(); if (!objVLyr.DataSource.IsOpen) objVLyr.DataSource.Op

19、en(); SharpMap.Data.FeatureDataRow tempFeat; for (uint i = 0; i count; i+) tempFeat = 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 Sh

20、arpMap.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; tempRow.Geometry = tempFeat.Geometry; SharpMap.Layers.

21、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 = ;

22、 lblProperty.Text += 屬性：; for (int j = 0; j tempFeat.Table.Columns.Count; j+) / lblProperty.Text += tempFeat.Table.Columnsi.ColumnName+ +tempFeati.ToString()+ lblProperty.Text += + tempFeat.Table.Columnsj.ColumnName; lblProperty.Text += + tempFeatj.ToString() + ; lblProperty.Visible = true; break; /

23、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.FeatureDataTable).Clone(); tempTable.LoadDataRow(tempFeat.ItemArray, false); FeatureDataRow t

24、empRow; tempRow = tempTable.RowstempTable.Rows.Count - 1 as FeatureDataRow; tempRow.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.Coun