高亮显示要素的另一种方法

高亮显示要素一般可以通过两种方式来实现。一是在地图资源管理器中增加一GraphicsLayer，然后在该图层中将要素重新画一次，另一种方式是设置资源绘图功能的MapDescription属性的CustomGraphic属性。

由于第一种方式使用的较多，在此将介绍第二种方式的实现。

在使用ArcGIS Server绘图功能时，MapDescription属性提供了一个值对象，通过该对象可以修改由ArcGIS Server地图服务生成的地图的显示与内容。

主要的代码如下：

         // 高亮显示的主体函数

public static void HighLightShow(Map map, DataTableCollection dtc)

  {

        MapFunctionality mf = (MapFunctionality)map.GetFunctionality("NorthAmericaMap");

        MapDescription mapDescription = mf.MapDescription;

        mapDescription.CustomGraphics = null;

 

        SimpleFillSymbol sfs = CreateSimpleFillSymbol();

 

        foreach(DataTable dt in dtc)

        {  

            if (dt.Rows.Count == 0)

                continue;

 

            HighLightPolygon(mapDescription, dt, sfs);

        }

 

        RefreshMap(map, "NorthAmericaMap");

    }

 

//HighLightShow方法调用到的函数如下

public static SimpleFillSymbol CreateSimpleFillSymbol()

    {

        ESRI.ArcGIS.ADF.ArcGISServer.RgbColor rgb;

        rgb = new ESRI.ArcGIS.ADF.ArcGISServer.RgbColor();

        rgb.Red = 255;

        rgb.Green = 0;

        rgb.Blue = 0;

        rgb.AlphaValue = 255;

        SimpleLineSymbol lineSym = new SimpleLineSymbol();

        lineSym.Color = rgb;

        lineSym.Width = 1.0;

        lineSym.Style = esriSimpleLineStyle.esriSLSSolid;

        SimpleFillSymbol sfs;

        sfs = new SimpleFillSymbol();

        sfs.Style = esriSimpleFillStyle.esriSFSForwardDiagonal;

        sfs.Color = rgb;

        sfs.Outline = lineSym;

 

        return sfs;

    }

 

public static void HighLightPolygon(MapDescription mapDescription, DataTable datatable, SimpleFillSymbol sfs)

    {

        int hasCount = 0;

        if (mapDescription.CustomGraphics != null)

            hasCount = mapDescription.CustomGraphics.Length;

        ESRI.ArcGIS.ADF.ArcGISServer.GraphicElement[] ges;

        ges = new GraphicElement[hasCount + datatable.Rows.Count];

        CopyCustomGraphics(ges, mapDescription);

       

        int geoIndex = GeometryFieldIndex(datatable);

        for (int i = 0; i < datatable.Rows.Count; i++)

        {

            ESRI.ArcGIS.ADF.Web.Geometry.Polygon polygon = datatable.Rows[i][geoIndex] as ESRI.ArcGIS.ADF.Web.Geometry.Polygon;

            PolygonN ags_map_polyn;

            ags_map_polyn = ESRI.ArcGIS.ADF.Web.DataSources.ArcGISServer.Converter.FromAdfPolygon(polygon);

            PolygonElement polyelement;

            polyelement = new PolygonElement();

            polyelement.Symbol = sfs;

            polyelement.Polygon = ags_map_polyn;

            ges[hasCount + i] = polyelement;

        }

       

        mapDescription.CustomGraphics = ges;       

    }

 

 

    public static void RefreshMap(Map map, string resourceName)

    {

        if (map.ImageBlendingMode == ImageBlendingMode.WebTier)

        {

            map.Refresh();

        }

        else if (map.ImageBlendingMode == ImageBlendingMode.Browser)

        {

            map.RefreshResource(resourceName);

        }

    }

public static void CopyCustomGraphics(GraphicElement[] ges, MapDescription mapDescription)

    {

        if (mapDescription.CustomGraphics != null)

        {

            for (int i = 0; i < mapDescription.CustomGraphics.Length; i++)

                ges[i] = mapDescription.CustomGraphics[i];

        }

}

 

public static int GeometryFieldIndex(DataTable datatable)

    {

        int geoIndex = -1;

        for (int i = 0; i < datatable.Columns.Count; i++)

        {

            if (datatable.Columns[i].DataType == typeof(ESRI.ArcGIS.ADF.Web.Geometry.Geometry))

            {

                // 找到Geometry字段的序号

                geoIndex = i;

                break;

            }

        }

 

        return geoIndex;

    }

 

 

//调用HighLightShow方法来显示查询结果：

public static void ShowIdentifyResult(Map map, DataTableCollection dtc)

    {

        string returnstring = string.Empty;

        foreach (DataTable dt in dtc)

        {

            if (dt.Rows.Count == 0)

                continue;

            returnstring += GetHtmlFromDataTable(dt);

        }

 

        HighLightShow(map, dtc);

 

        returnstring = returnstring.Replace(""r"n", "");

        returnstring = returnstring.Replace(""n", "");

        string functionValue = "var theForm = document.forms[0];";

        functionValue += "theForm.FunctionValue.Value='" + returnstring + "';";

        functionValue += "open('IdentifyResult.htm', 'IdentifyResult');";

        AddJavaScriptCallback(map, functionValue);

    }

 //ShowIdentifyResult中调用到的函数

public static void AddJavaScriptCallback(Map map, string executeString)

    {

        object[] oa = new object[1];

        oa[0] = executeString;

        CallbackResult cr = new CallbackResult(null, null, "javascript", oa);

        map.CallbackResults.Add(cr);

    }

 

    public static string GetHtmlFromDataTable(DataTable dt)

    {

        GridView gd = new GridView();

        gd.ToolTip = dt.TableName;

        gd.Caption = dt.TableName;

        gd.DataSource = dt;

        gd.DataBind();

        gd.Visible = true;

        gd.BorderWidth = 0;

        gd.CssClass = "list-line";

        gd.CellPadding = 3;

        gd.CellSpacing = 1;

        gd.HeaderStyle.CssClass = "barbg";

        gd.HeaderStyle.HorizontalAlign = HorizontalAlign.Center;

        gd.RowStyle.CssClass = "listbg";

 

        string returnString = string.Empty;

        using (System.IO.StringWriter sw = new System.IO.StringWriter())

        {

            HtmlTextWriter htw = new HtmlTextWriter(sw);

            gd.RenderControl(htw);

            htw.Flush();

            string tempStr = sw.ToString();

            returnString += tempStr;

        }

        return returnString;

    }

 

//查询函数，调用ShowIdentifyResult获得查询结果

public static void Identify(Map map, ESRI.ArcGIS.ADF.Web.Geometry.Geometry mapGeometry)

    {

        IGISFunctionality gisfunc = map.GetFunctionality("NorthAmericaMap");

        if (gisfunc == null)

            return;

       

        IGISResource gisresource = gisfunc.Resource;

        bool supportquery = gisresource.SupportsFunctionality(typeof(IQueryFunctionality));

        if (!supportquery)

            return;

 

        IQueryFunctionality qfunc;

        qfunc = gisresource.CreateFunctionality(typeof(IQueryFunctionality), null) as IQueryFunctionality;

        string[] lIDs, lNames;

        qfunc.GetQueryableLayers(null, out lIDs, out lNames);

 

        ESRI.ArcGIS.ADF.Web.SpatialFilter spatialfilter = new ESRI.ArcGIS.ADF.Web.SpatialFilter();

        spatialfilter.ReturnADFGeometries = false;

        spatialfilter.MaxRecords = 1000;

        spatialfilter.Geometry = mapGeometry;

 

        System.Data.DataSet dataset = new System.Data.DataSet();

        for (int i = 0; i < lIDs.Length; i++)

        {

            System.Data.DataTable datatable = qfunc.Query(null, lIDs[i], spatialfilter);

            if (datatable == null)

                continue;

            datatable.TableName = lNames[i];

            dataset.Tables.Add(datatable);

        }  

 

        DataTableCollection dtc = dataset.Tables;

        ShowIdentifyResult(map, dtc);

    }