ArcGIS.Server.9.2.DotNet自带例子分析（六、二）

目的：
1.arcgis server9.2 ADF实现Buffer Select功能。
准备工作：
1.（六、一）的工程，具体见前篇。

开始：
1.在Toolbar1中新建一个Tool,ClientAction属性为"Point" ；Name属性为"BufferSelect" ；ServerActionAssembly属性为SelectTool；ServerActionClass属性为SelectTool.BufferTool；Text属性为"Buffer Point" ；ToolTip属性为"Buffer Point" 。
2.新建BufferTool.cs文件用来实现BufferSelect Tool的功能，BufferSelect实现IMapServerToolAction接口，具体代码和说明如下：

  1void IMapServerToolAction.ServerAction(ToolEventArgs args)
  2        {
  3            //获取Map控件
  4            ESRI.ArcGIS.ADF.Web.UI.WebControls.Map mapctrl = (ESRI.ArcGIS.ADF.Web.UI.WebControls.Map)args.Control;
  5            //点参数
  6            PointEventArgs pointargs = (PointEventArgs)args;
  7            //像素点
  8            System.Drawing.Point screenpoint = pointargs.ScreenPoint;
  9            //像素坐标转换成地理坐标
 10            ESRI.ArcGIS.ADF.Web.Geometry.Point mappoint = ESRI.ArcGIS.ADF.Web.Geometry.Point.ToMapPoint(screenpoint.X, screenpoint.Y, mapctrl.GetTransformationParams(ESRI.ArcGIS.ADF.Web.Geometry.TransformationDirection.ToMap));
 11            //从Session["BufferDistance"]中获取冗余值
 12            string strbd = (string)mapctrl.Page.Session["BufferDistance"];
 13            float bufferdistance;
 14            //转成float型
 15            if (!Single.TryParse(strbd, out bufferdistance))
 16            {
 17                bufferdistance = 0.0F;
 18            }
 19
 20            //相互连接的直线或曲线
 21            System.Drawing.Drawing2D.GraphicsPath gpath = new System.Drawing.Drawing2D.GraphicsPath();
 22            //绘制椭圆
 23            gpath.AddEllipse((float)mappoint.X - (bufferdistance / 2), (float)mappoint.Y - (bufferdistance / 2), bufferdistance, bufferdistance);
 24            //Flatten的参数
 25            System.Drawing.Drawing2D.Matrix translateMatrix = new System.Drawing.Drawing2D.Matrix();
 26            translateMatrix.Translate(0, 0);
 27
 28            //误差值，Flatten的参数
 29            float flattening = bufferdistance / 1000;
 30            //将gpath曲线转换成相连接的线段序列
 31            gpath.Flatten(translateMatrix, flattening);
 32
 33            //点集合
 34            ESRI.ArcGIS.ADF.Web.Geometry.PointCollection pc = new ESRI.ArcGIS.ADF.Web.Geometry.PointCollection();
 35            foreach (System.Drawing.PointF dpnt in gpath.PathPoints)
 36            {
 37                pc.Add(new ESRI.ArcGIS.ADF.Web.Geometry.Point(dpnt.X, dpnt.Y));
 38            }
 39
 40            //环形
 41            ESRI.ArcGIS.ADF.Web.Geometry.Ring ring = new ESRI.ArcGIS.ADF.Web.Geometry.Ring();
 42            ring.Points = pc;
 43            ESRI.ArcGIS.ADF.Web.Geometry.RingCollection rings = new ESRI.ArcGIS.ADF.Web.Geometry.RingCollection();
 44            rings.Add(ring);
 45            //多边形
 46            ESRI.ArcGIS.ADF.Web.Geometry.Polygon mappoly = new ESRI.ArcGIS.ADF.Web.Geometry.Polygon();
 47            mappoly.Rings = rings;
 48
 49            
 50            IEnumerable gfc = mapctrl.GetFunctionalities();
 51            ESRI.ArcGIS.ADF.Web.DataSources.Graphics.MapResource gResource = null;
 52            foreach (IGISFunctionality gfunc in gfc)
 53            {
 54                if (gfunc.Resource.Name == "Buffer")
 55                {
 56                    //获取Buffer
 57                    gResource = (ESRI.ArcGIS.ADF.Web.DataSources.Graphics.MapResource)gfunc.Resource;
 58                }
 59            }
 60            if (gResource == null)
 61            {
 62                throw new Exception("Buffer Graphics layer not in MapResourceManager");
 63            }
 64
 65            ESRI.ArcGIS.ADF.Web.Display.Graphics.ElementGraphicsLayer glayer = null;
 66            //查找ElementGraphicsLayer在Buffer中
 67            foreach (System.Data.DataTable dt in gResource.Graphics.Tables)
 68            {
 69                if (dt is ESRI.ArcGIS.ADF.Web.Display.Graphics.ElementGraphicsLayer)
 70                {
 71                    glayer = (ESRI.ArcGIS.ADF.Web.Display.Graphics.ElementGraphicsLayer)dt;
 72                    break;
 73                }
 74
 75            }
 76            //如果Buffer中没有ElementGraphicsLayer就新增加一个ElementGraphicsLayer
 77            if (glayer == null)
 78            {
 79                glayer = new ESRI.ArcGIS.ADF.Web.Display.Graphics.ElementGraphicsLayer();
 80                gResource.Graphics.Tables.Add(glayer);
 81            }
 82            //清除ElementGraphicsLayer中的内容
 83            glayer.Clear();
 84            
 85            ESRI.ArcGIS.ADF.Web.Geometry.Geometry geom = (ESRI.ArcGIS.ADF.Web.Geometry.Geometry)mappoly;
 86            //设置点显示
 87            ESRI.ArcGIS.ADF.Web.Display.Graphics.GraphicElement ge = new ESRI.ArcGIS.ADF.Web.Display.Graphics.GraphicElement(geom, System.Drawing.Color.Green);
 88            //设置透明度
 89            ge.Symbol.Transparency = 70.0;
 90            //添加到Buffer中进行显示
 91            glayer.Add(ge);
 92            //目标图层名称
 93            string targetlayername = (string)mapctrl.Page.Session["TargetLayer"];
 94            //Data Layers Resource index为2
 95            int resource_index = 2;
 96            int layer_index = 0;
 97            //获取Data Layers的MapFunctionality
 98            ESRI.ArcGIS.ADF.Web.DataSources.IMapFunctionality mf = (ESRI.ArcGIS.ADF.Web.DataSources.IMapFunctionality)mapctrl.GetFunctionality(resource_index);
 99            ESRI.ArcGIS.ADF.Web.DataSources.IGISResource gisresource = mf.Resource;
            //是否支持QueryFunctionality
            bool supported = gisresource.SupportsFunctionality(typeof(ESRI.ArcGIS.ADF.Web.DataSources.IQueryFunctionality));
            if (supported)
            {
                //创建QueryFunctionality
                ESRI.ArcGIS.ADF.Web.DataSources.IQueryFunctionality qfunc = (ESRI.ArcGIS.ADF.Web.DataSources.IQueryFunctionality)gisresource.CreateFunctionality(typeof(ESRI.ArcGIS.ADF.Web.DataSources.IQueryFunctionality), null);
                string[] lids;
                string[] lnames;
                //查询图层的id和名称
                qfunc.GetQueryableLayers(null, out lids, out lnames);

                //获取目标图层的index
                for (int i = 0; i < lnames.Length; i++)
                {
                    if (lnames[i] == targetlayername)
                    {
                        layer_index = i;
                        break;
                    }
                }

                //空间过滤
                ESRI.ArcGIS.ADF.Web.SpatialFilter spatialfilter = new ESRI.ArcGIS.ADF.Web.SpatialFilter();
                //是否返回地理元素
                spatialfilter.ReturnADFGeometries = true;
                //返回最大记录数
                spatialfilter.MaxRecords = 1000;
                spatialfilter.Geometry = mappoly;
                //查询目标图层并且把结果存入DataTable
                System.Data.DataTable datatable = qfunc.Query(null, lids[layer_index], spatialfilter);

                ESRI.ArcGIS.ADF.Web.DataSources.Graphics.MapResource selresource = null;
                //获取Selection
                foreach (IGISFunctionality gfunc in gfc)
                {
                    if (gfunc.Resource.Name == "Selection")
                    {
                        selresource = (ESRI.ArcGIS.ADF.Web.DataSources.Graphics.MapResource)gfunc.Resource;
                    }
                }
                if (selresource == null)
                {
                    return;
                }
                ESRI.ArcGIS.ADF.Web.Display.Graphics.ElementGraphicsLayer slayer = null;
                //获取Selection的ElementGraphicsLayer
                foreach (System.Data.DataTable dt in selresource.Graphics.Tables)
                {
                    if (dt is ESRI.ArcGIS.ADF.Web.Display.Graphics.ElementGraphicsLayer)
                    {
                        slayer = (ESRI.ArcGIS.ADF.Web.Display.Graphics.ElementGraphicsLayer)dt;
                        break;
                    }
                }
                //如果Selection的ElementGraphicsLayer为bull就新建ElementGraphicsLayer
                if (slayer == null)
                {
                    slayer = new ESRI.ArcGIS.ADF.Web.Display.Graphics.ElementGraphicsLayer();
                    selresource.Graphics.Tables.Add(slayer);
                }
                //清除Selection的ElementGraphicsLayer的内容
                slayer.Clear();

                DataRowCollection drs = datatable.Rows;

                int shpind = -1;
                for (int i = 0; i < datatable.Columns.Count; i++)
                {
                    if (datatable.Columns[i].DataType == typeof(ESRI.ArcGIS.ADF.Web.Geometry.Geometry))
                    {
                        shpind = i;
                        break;
                    }
                }

                try
                {
                    foreach (DataRow dr in drs)
                    {
                        ESRI.ArcGIS.ADF.Web.Geometry.Geometry sgeom = (ESRI.ArcGIS.ADF.Web.Geometry.Geometry)dr[shpind];
                        ESRI.ArcGIS.ADF.Web.Display.Graphics.GraphicElement sge = new ESRI.ArcGIS.ADF.Web.Display.Graphics.GraphicElement(sgeom, System.Drawing.Color.Yellow);
                        //设置透明度
                        sge.Symbol.Transparency = 50.0;
                        //添加到Selection的ElementGraphicsLayer进行显示
                        slayer.Add(sge);
                    }
                }
                catch
                {
                    throw new Exception("No geometry available in datatable");
                }
                //获取CheckBox1的值
                string cbxvalue = (string)mapctrl.Page.Session["CheckBox1Value"];
                //获取GridView1
                GridView gdview = (GridView)mapctrl.Page.FindControl("GridView1");
                object[] oa = new object[1];
                string showtable = "'hidden'";

                if (bool.Parse(cbxvalue))
                {
                    //把查询结果作为GridView1数据源进行绑定
                    gdview.DataSource = datatable;
                    gdview.DataBind();

                    string returnstring = null;

                    using (System.IO.StringWriter sw = new System.IO.StringWriter())
                    {
                        HtmlTextWriter htw = new HtmlTextWriter(sw);
                        gdview.RenderControl(htw);
                        htw.Flush();
                        returnstring = sw.ToString();
                    }

                    CallbackResult cr = new CallbackResult("div", "griddiv", "innercontent", returnstring);
                    mapctrl.CallbackResults.Add(cr);

                    if (datatable.Rows.Count > 1)
                        showtable = "'visible'";

                }
                string sa = "var griddiv = document.getElementById('griddiv');";
                sa += "griddiv.style.visibility = " + showtable + ";";
                oa[0] = sa;
                CallbackResult cr1 = new CallbackResult(null, null, "javascript", oa);
                mapctrl.CallbackResults.Add(cr1);

                if (mapctrl.ImageBlendingMode == ImageBlendingMode.WebTier)
                { mapctrl.Refresh(); }
                else if (mapctrl.ImageBlendingMode == ImageBlendingMode.Browser)
                {
                    mapctrl.RefreshResource(gResource.Name);
                    mapctrl.RefreshResource(selresource.Name);
                }

            }
        }

3.在Default.aspx页面上添加TextBox1，用来buffer值的输入，当值输入完成后把这个值存入到Session["BufferDistance"]中，在Page_Load事件中为这个TextBox1添加onkeyup的脚本方法名为ChangeBufferContext()。

protected void Page_Load(object sender, EventArgs e)
        {
                        
            TextBox1.Attributes.Add("onkeyup", "ChangeBufferContext()");
        }

4.接下在编写脚本方法ChangeBufferContext，切换到html视图添加这个方法，代码和说明具体如下：

 1function ChangeClient()
 2         {
 3            var message;
 4            
 5            //目标图层选择
 6            if (context == 'DDLContext')
 7            {
 8              //获取选择值
 9              var ddl1value = document.getElementById('DropDownList1').value;
              message = 'ddl';
              message += ',' + ddl1value;  
            } 
            
            //是否在表格中显示数据
            if (context == 'CheckBox')
            {
                var checkboxvalue = document.getElementById('CheckBox1').checked;
                
                message = 'checkbox';
                message += ',' + checkboxvalue;
            }
            
            //buffer值
             if (context == 'BufferTextBox')
             {
                var bufboxvalue = document.getElementById('TextBox1').value;
                
                message = 'bufbox';
                message += ',' + bufboxvalue;
            
            }     
            
            
            //回调方法执行服务端是事情     
            <%=sCallBackFunctionInvocation%>
         }
         
         //TextBox1的onkeyup事件
         function ChangeBufferContext()
         {
            context = 'BufferTextBox'; 
            ChangeClient();        
         }

5.完成客户的js代码后还需要在服务端的RaiseCallbackEvent方法中对请求进行处理，具体代码和说明如下：

 1 //接受客户端的请求进行处理
 2        public void RaiseCallbackEvent(string eventArgs)
 3        {
 4            if (eventArgs.Contains("ddl"))
 5            {
 6                ChangeDropDownListServer(eventArgs);
 7            }
 8            else if (eventArgs.Contains("checkbox"))
 9            {
                ChangeCheckServer(eventArgs);
            }
            else if (eventArgs.Contains("bufbox"))
            {
                ChangeBufferDistanceServer(eventArgs);
            }
        }

        //保存Buffer值到到Session["BufferDistance"]中
        public void ChangeBufferDistanceServer(string ea)
        {
            char[] parser_char = { ',' };
            string[] messages = ea.Split(parser_char);
            string bufbox = messages[1];
            if (bufbox != string.Empty)
            {
                Session["BufferDistance"] = bufbox;
            }
        }

6.接下来在添加一个button用来实现ClearSelection功能，具体的html代码如下：

<input type="button" ID="Button1" Style="left: 575px; value="Clear Selection" onclick="ChangeClearSelection()" />

7.还需要编写ChangeClearSelection脚本方法来实现这个功能，具体代码和说明如下：

 1//清除选择
 2         function ChangeClearSelection()
 3         {
 4            context = "ClearSelectionButton";
 5            ChangeClientADF();
 6        }
 7         
 8        function ChangeClientADF()
 9        {              
            if (context == "ClearSelectionButton"){
                message = "clearselectionbutton";
            }                 
            <%=sADFCallBackFunctionInvocation%>            
         }       

8.同样还需要在服务端的RaiseCallbackEvent方法中对请求进行处理，具体代码和说明如下：

 1//接受客户端的请求进行处理
 2        public void RaiseCallbackEvent(string eventArgs)
 3        {
 4            if (eventArgs.Contains("ddl"))
 5            {
 6                ChangeDropDownListServer(eventArgs);
 7            }
 8            else if (eventArgs.Contains("checkbox"))
 9            {
                ChangeCheckServer(eventArgs);
            }
            else if (eventArgs.Contains("bufbox"))
            {
                ChangeBufferDistanceServer(eventArgs);
            }
            else if (eventArgs.Contains("clearselectionbutton"))
            {
                ChangeClearSelection();
            }
        }

        //清除
        public void ChangeClearSelection()
        {
            IEnumerable gfc = Map1.GetFunctionalities();
            ESRI.ArcGIS.ADF.Web.DataSources.Graphics.MapResource gResource = null;
            foreach (IGISFunctionality gfunc in gfc)
            {
                if (gfunc.Resource is ESRI.ArcGIS.ADF.Web.DataSources.Graphics.MapResource)
                {
                    gResource = (ESRI.ArcGIS.ADF.Web.DataSources.Graphics.MapResource)gfunc.Resource;
                    gResource.Graphics.Clear();
                }
            }

            Map1.Refresh();

            object[] oa = new object[1];
            string showtable = "'hidden'";
            string sa = "var griddiv = document.getElementById('griddiv');";
            sa += "griddiv.style.visibility = " + showtable + ";";
            oa[0] = sa;
            oa[0] = sa;
            CallbackResult cr1 = new CallbackResult(null, null, "javascript", oa);
            Map1.CallbackResults.Add(cr1);

            returnstring = Map1.CallbackResults.ToString();
        }

9.这样就完成了这个例子，可以运行查看效果。