Silverlight客户端实现区域像元统计以及地形剖面图的绘制
开始之前的一段废话：
放假回家了也就没有写博客了，家里没有网，偶尔也只能用手机上一上，看一看是否有新的评论和回复，是否有和我研究相关的博文和动态。今天是三月一号，学校的校园网帐号解封了，于是便把寒假部分的工作内容总结一下，在此也和大家一起分享我的心得，希望对各位读者能有所帮助。
本文的例子是我帮一位兄弟做的，算起还是我的学长，只不过不同学校，具体的要求如下：
http://bbs.esrichina-bj.cn/ESRI/viewthread.php?tid=124221&extra=page%3D1
于是假期的时候便做了一个该功能的例子，然后还加了一点小功能。后面的文章中将会详细介绍，下面就进入正题吧！
一、本文实现的功能
1.1 要素查询功能
根据要素属性，查询出相应的要素
1.2 栅格数据的像元统计
例如输入一个几何图形(点，线，面)可以计算出该图像范围内栅格数据的像元信息，如：像元最大值，最小值，以及平均值等，具体如下图所示：
1.3 绘制地形剖面图
该功能和官网的这个例子差不多：
http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#SurfaceProfile
(不知道为什么，我这里查看不了这里例子)
效果如下图所示：
二、使用到的数据和知识
2.1地图数据
本例的地形高程数据来自于国际科学数据服务平台，下载网址：
http://datamirror.csdb.cn/index.jsp
本例的各区县要素数据来自于国家基础地理信息中心，下载网址：
http://nfgis.nsdi.gov.cn/nfgis/chinese/c_xz.htm
上面的地图是我自己在ArcMap中制作的一张地图，外加了一点地形阴影效果，这是在ArcMap中的图层列表
各县面要素图层
最后通过以上数据得到了本文使用的底图。在查询部分中，实际上查询的就是各区县的面要素，可通过输入曲线的民称或编号来查询出相对应的县，然后再通过调研像元统计的GP服务工具，即可实现像元统计，得到对应区县范围内像元的最大值，最小值等信息，实际上这里的值也就是对应区县的海拔(准确度由下载的高程数据所决定)，最后的地图：
2.2 使用到如下的知识：
2.2.1 要素的属性查询
2.2.2 GP服务的调用
2.2.3 通过开源的Silverlight图表控件：OxyPlot
以上前两部分内容都在之前的博文中讲过，所以不是本文的重点。关于OxyPlot图表控件也很简单，这里不会过多的解释说明。官网有很好的帮助文档。
三、实现过程
3.1 查询(要素属性查询和空间查询)
可参考之前的博文：
http://www.cnblogs.com/potential/archive/2013/01/31/2882244.html
3.2 根据查询得到的面要素，计算出面要素对应区域内的像元信息。
3.2.1 发布像元统计的GP服务
这里主要用到的就是GP服务。下面是本文的GP服务模型：
其中ZoneFiled就是统计字段，InputFeature为输入的要素，ZonalRaster为统计的删格数据
提醒：在10.1中可以将栅格数据作为输入参数。在10.0中不可以，如果您是10.0版本的，那么这里你只能在建模的时候指定栅格数据，然后去掉设置为模型参数。在10.1中如果你有可数的几个不同栅格数据，那么你可以将其添加到ArcMap中，在发布GP服务的时候，会提示你从列表选择还是自定义栅格数据，这个时候你可以选择从列表选择。然后你可以将ArcMap中的删格数据图层添加到选择列表中，最后在Web端调用的时候，你只需要输入栅格数据列表中对于栅格数据的名称即可，例如本文的列表如下：
这里可以看出只有一个栅格数据选项：hunandata。
3.2.2 Web端调用GP服务
调用GP服务的过程之前的博文也有讲到，可参考这里：
http://www.cnblogs.com/potential/archive/2012/11/03/2752289.html
下面是本文的调用代码：
private void AccessGPService(FeatureSet featureset) { List<GPParameter> gppara = new List<GPParameter>(); //输入GP服务的参数 gppara.Add(new GPString("ZoneFiled", "OBJECTID")); gppara.Add(new GPFeatureRecordSetLayer("InputFeature", featureset)); gppara.Add(new GPString("ZonalRaster", "hunandata")); _geoprocessor.SubmitJobAsync(gppara); } private void _geoprocessor_JobCompleted(object sender, JobInfoEventArgs e) { HttpWebRequest.RegisterPrefix("http://", System.Net.Browser.WebRequestCreator.ClientHttp); Geoprocessor gp = sender as Geoprocessor; //请求GP服务的结果 gp.GetResultDataAsync(e.JobInfo.JobId, "ResultTable"); } private void _geoprocessor_GetResultDataCompleted(object sender, GPParameterEventArgs e) { MyDataGrid.ItemsSource = null; GPRecordSet gpr = e.Parameter as GPRecordSet; if (gpr.FeatureSet != null) { for (int i = 0; i < gpr.FeatureSet.Features.Count; i++) { for (int j = 2; j < gpr.FeatureSet.Features[i].Attributes.Count; j++) { //这里本文有个Bug，就是当FeatureDataGrid绑定到GraphicsLayer后， //如果修改GrapicsLayer的属性(增加或者删除)会报错，以下代码不能通过，所以这里选择了先修改再绑定 List<string> keyList = gpr.FeatureSet.Features[i].Attributes.Keys.ToList<string>(); List<object> valueList = gpr.FeatureSet.Features[i].Attributes.Values.ToList(); graphicsLayer.Graphics[i].Attributes.Add(keyList[j], valueList[j]); } } //在此绑定DataGrid，不然会出现异常 MyDataGrid.GraphicsLayer = graphicsLayer; MyDataGrid.Visibility = Visibility.Visible; //绘制地形图 if (createPlot == true) { CreatePlot(); TerrainBorder.Visibility = Visibility.Visible; } featureSet.Features.Clear(); } //等待过程 BusyRectangle.Visibility = Visibility.Collapsed; busyIndicator.IsBusy = false; } private void _geoprocessor_Failed(object sender, TaskFailedEventArgs e) { MessageBox.Show(e.Error.ToString()); }
以上是调用GP服务的代码，这里有个Bug。
最后的统计结果如下所示：
3.2.3 Web客户端绘制地形图
这里借助的是开源的图表控件：OxyPlot。感觉绘制图表很强大，而且开源啊。
绘制地形剖面图的功能大致上的过程如下：
首先在地图上绘制一条线，然后等分这条线，例如一百份，然后得到这一百个点的像元统计值(最后的值就是海拔值，这里数据的准确度和提供的高程数据经度有关，高程数据经度越高，结果也就越准确），得到一百个点的高程数据之后，就通过OxyPlot绘图了。
具体代码：
a.OxyPlot绘图
声明一个PlotModel,PlotModel代表绘制图表的类型。
PlotModel plotModel = null;
在构造函数中初始化：
var linearAxis1 = new LinearAxis(AxisPosition.Bottom) { IsZoomEnabled=false,Title="距离"}; plotModel.Axes.Add(linearAxis1); var linearAxis2 = new LinearAxis(AxisPosition.Left) { IsZoomEnabled=false,Title="海拔"}; plotModel.Axes.Add(linearAxis2); areaSeries1 = new AreaSeries { Fill=OxyColors.DarkOrange, DataFieldX="距离", DataFieldY="最高海拔", DataFieldX2 = "距离", DataFieldY2 = "最低海拔", Color=OxyColors.Red, StrokeThickness=0, MarkerFill=OxyColors.Transparent, };
b.然后绘制一条直线并构造点：
private void CreatPoint(ESRI.ArcGIS.Client.Geometry.Polyline polyline,int count) { //默认沿直线构造一百个点 double xStep = (polyline.Paths[0][1].X - polyline.Paths[0][0].X) / count; double yStep = (polyline.Paths[0][1].Y - polyline.Paths[0][0].Y) / count; interval = Math.Sqrt(xStep * xStep + yStep * yStep); //清空FeatureSet便于之后的GP服务调用 if (featureSet.Features.Count > 0) { featureSet.Features.Clear(); } for (int i = 0; i < count; i++) { MapPoint mp = new MapPoint(polyline.Paths[0][0].X + i*xStep, polyline.Paths[0][0].Y + i*yStep); mp.SpatialReference = map1.SpatialReference; Graphic gPoint = new Graphic() { Symbol = new SimpleMarkerSymbol() { Color=new SolidColorBrush(Colors.Blue), Size=8, Style=SimpleMarkerSymbol.SimpleMarkerStyle.Circle }, Geometry=mp, }; featureSet.Features.Add(gPoint); graphicsLayer.Graphics.Add(gPoint); } }
c.调用GP服务统计像元值(代码如上)
d.根据统计值绘制图表，这里Graphic的MAX属性表示的即为最高海拔，对于点要素MAX和MIN值是一样的。
private void CreatePlot() { areaSeries1.Points.Clear(); areaSeries1.Points2.Clear(); plotModel.Series.Clear(); for (int i = 0; i < graphicsLayer.Graphics.Count; i++) { areaSeries1.Points.Add(new DataPoint(interval * i, Convert.ToDouble(graphicsLayer.Graphics[i].Attributes["MAX"]))); areaSeries1.Points2.Add(new DataPoint(interval * i, 0)); } plotModel.Series.Add(areaSeries1); areaSeries1.Title = "海拔"; Myplot.Model = plotModel; createPlot = false; }
最后的MainPage.cs代码：
View Code
using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Shapes; using ESRI.ArcGIS.Client.Symbols; using ESRI.ArcGIS.Client.Geometry; using ESRI.ArcGIS.Client.Tasks; using ESRI.ArcGIS.Client; using System.Text.RegularExpressions; using OxyPlot.Silverlight; using OxyPlot; namespace QueryAndStatisticDemo { public partial class MainPage : UserControl { //用于查询的Task QueryTask queryTask = new QueryTask(); //声明一个Draw,用于绘制查询的区域，进行空间查询 Draw myDraw; //绘制的Geomotry ESRI.ArcGIS.Client.Geometry.Geometry drawGeometry; //查询SQL字符串 string QueryString; //选择查询结果中的Graphic Graphic selectedGraphic; //地理处理服务 Geoprocessor _geoprocessor = null; //输入要素集 FeatureSet featureSet = new FeatureSet(); GraphicsLayer graphicsLayer; PlotModel plotModel = null; //Interval AreaSeries areaSeries1; double interval; bool createPlot = false; public MainPage() { InitializeComponent(); plotModel = new PlotModel("地形剖面图"); var linearAxis1 = new LinearAxis(AxisPosition.Bottom) { IsZoomEnabled=false,Title="距离"}; plotModel.Axes.Add(linearAxis1); var linearAxis2 = new LinearAxis(AxisPosition.Left) { IsZoomEnabled=false,Title="海拔"}; plotModel.Axes.Add(linearAxis2); areaSeries1 = new AreaSeries { Fill=OxyColors.DarkOrange, DataFieldX="距离", DataFieldY="最高海拔", DataFieldX2 = "距离", DataFieldY2 = "最低海拔", Color=OxyColors.Red, StrokeThickness=0, MarkerFill=OxyColors.Transparent, }; graphicsLayer = map1.Layers["QueryResultLayer"] as GraphicsLayer; queryTask.Url = "http://qzj-pc:6080/arcgis/rest/services/Provinces_Map/HunanMap/MapServer/3"; queryTask.AutoNormalize = true; //很重要，否则出现查询成功和失败交替出现的现象 queryTask.DisableClientCaching = true; queryTask.ExecuteCompleted += new EventHandler<QueryEventArgs>(queryTask_ExecuteCompleted); queryTask.Failed += new EventHandler<TaskFailedEventArgs>(queryTask_Failed); _geoprocessor = new Geoprocessor("http://qzj-pc:6080/arcgis/rest/services/RasterStatisticServer/GPServer/DemStatisticsRaster"); _geoprocessor.JobCompleted += new EventHandler<JobInfoEventArgs>(_geoprocessor_JobCompleted); _geoprocessor.Failed += new EventHandler<TaskFailedEventArgs>(_geoprocessor_Failed); _geoprocessor.GetResultDataCompleted += new EventHandler<GPParameterEventArgs>(_geoprocessor_GetResultDataCompleted); myDraw = new Draw(map1); myDraw.DrawMode = DrawMode.Polygon; myDraw.IsEnabled = false; myDraw.FillSymbol = new SimpleFillSymbol() { BorderBrush = new SolidColorBrush(Colors.Black), BorderThickness = 3, Fill = new SolidColorBrush(Colors.Red), }; myDraw.LineSymbol = new LineSymbol() { Color=new SolidColorBrush(Colors.Red), Width=3 }; myDraw.DrawComplete += new EventHandler<DrawEventArgs>(myDraw_DrawComplete); QueryTypeCombox.ItemsSource = AttributeString.GraphicAttributesEnNameString; } private void myDraw_DrawComplete(object sender, DrawEventArgs e) { graphicsLayer.Graphics.Clear(); drawGeometry = e.Geometry; myDraw.IsEnabled = false; if (drawGeometry is ESRI.ArcGIS.Client.Geometry.Polyline) { CreatPoint((ESRI.ArcGIS.Client.Geometry.Polyline)drawGeometry,100); BusyRectangle.Visibility = Visibility.Visible; busyIndicator.IsBusy = true; AccessGPService(featureSet); } else { StartQueryBySpatial(e.Geometry); } } private void ExpressionButton_Click(object sender, RoutedEventArgs e) { string pattern = @"^[0-9]*$"; Button button = sender as Button; Match m = Regex.Match(button.Content.ToString(), pattern); if (m.Success) ExpressionTextBox.Text = string.Format("{0}{1}", ExpressionTextBox.Text, button.Content); else ExpressionTextBox.Text = string.Format("{0} {1} ", ExpressionTextBox.Text, button.Content); } private void ExpressionQueryButton_Click(object sender, RoutedEventArgs e) { CreatQueryString(); StartQueryBySQL(QueryString); } private void SpatialQueryButton_Click(object sender, RoutedEventArgs e) { ExpressionTextBox.Text = ""; myDraw.DrawMode = DrawMode.Polygon; myDraw.IsEnabled = true; } private void FiledsCombox_SelectionChanged(object sender, SelectionChangedEventArgs e) { ComboBox comb = sender as ComboBox; if (comb.SelectedIndex != -1) { int index = comb.SelectedIndex; ExpressionTextBox.Text = string.Format("{0}{1}", ExpressionTextBox.Text, comb.SelectedItem.ToString()); } comb.SelectedIndex = -1; } private void ExpressionTextBox_KeyDown(object sender, System.Windows.Input.KeyEventArgs e) { // 按了回车键就向服务端发送数据 if (e.Key == Key.Enter) { CreatQueryString(); StartQueryBySQL(QueryString); } } private void QoutButton_Click(object sender, RoutedEventArgs e) { Button button = sender as Button; ExpressionTextBox.Text = string.Format("{0}{1}", ExpressionTextBox.Text, button.Content); } private void NoButton_Click(object sender, RoutedEventArgs e) { Button button = sender as Button; ExpressionTextBox.Text = string.Format("{0} {1}", ExpressionTextBox.Text, button.Content); } private void ClearGraphicsButton_Click(object sender, RoutedEventArgs e) { graphicsLayer.Graphics.Clear(); } private void GraphicsLayer_MouseLeftButtonDown(object sender, GraphicMouseButtonEventArgs e) { if (selectedGraphic != null) { selectedGraphic.UnSelect(); selectedGraphic.Symbol = new SimpleFillSymbol() { BorderBrush = new SolidColorBrush(Colors.Red), BorderThickness = 2, Fill = new SolidColorBrush(Colors.Green) }; } e.Graphic.Select(); e.Graphic.Symbol = new SimpleFillSymbol() { Fill=new SolidColorBrush(Colors.Red), BorderBrush = new SolidColorBrush(Colors.Yellow), BorderThickness=3 }; if (e.Graphic.Selected&&MyDataGrid.GraphicsLayer!=null) MyDataGrid.ScrollIntoView(e.Graphic, null); selectedGraphic = e.Graphic; } #region 查询失败几完成事件 private void queryTask_ExecuteCompleted(object sender, QueryEventArgs e) { graphicsLayer.ClearGraphics(); if (e.FeatureSet.Features.Count > 0) { foreach (Graphic resultFeature in e.FeatureSet.Features) { if (drawGeometry != null) { //查询结果落在绘制的多边形之内 if (resultFeature.Geometry.Extent.XMax < drawGeometry.Extent.XMax && resultFeature.Geometry.Extent.XMin > drawGeometry.Extent.XMin && resultFeature.Geometry.Extent.YMax < drawGeometry.Extent.YMax && resultFeature.Geometry.Extent.YMin > drawGeometry.Extent.YMin) { resultFeature.Symbol = new SimpleFillSymbol() { BorderBrush = new SolidColorBrush(Colors.Red), BorderThickness = 2, Fill = new SolidColorBrush(Colors.Green) }; featureSet.Features.Add(resultFeature); graphicsLayer.Graphics.Add(resultFeature); } } else { resultFeature.Symbol = new SimpleFillSymbol() { BorderBrush = new SolidColorBrush(Colors.Red), BorderThickness = 2, Fill = new SolidColorBrush(Colors.Green) }; featureSet.Features.Add(resultFeature); graphicsLayer.Graphics.Add(resultFeature); } } if (graphicsLayer.Graphics.Count < 1) MessageBox.Show("没有查询到目标要素！"); } else { MessageBox.Show("没有查询到目标要素！"); } drawGeometry = null; } private void queryTask_Failed(object sender, TaskFailedEventArgs e) { MessageBox.Show("Query failed: " + e.Error); } #endregion #region 查询自定义方法 /// <summary> /// 条件查询 /// </summary> /// <param name="sqlString">查询SQL语句</param> private void StartQueryBySQL(string sqlString) { queryTask.CancelAsync(); if (ExpressionTextBox.Text == "") return; Query query = new Query(); query.ReturnGeometry = true; query.OutFields.AddRange(new string[] { "NAME99", "ADCODE99" }); query.Where = sqlString; query.OutSpatialReference = map1.SpatialReference; queryTask.ExecuteAsync(query); } /// <summary> /// 空间查询 /// </summary> /// <param name="geometry">几何图形</param> private void StartQueryBySpatial(ESRI.ArcGIS.Client.Geometry.Geometry geometry) { queryTask.CancelAsync(); Query query = new Query(); query.ReturnGeometry = true; query.OutFields.AddRange(new string[] { "NAME99", "ADCODE99" }); query.Geometry = geometry; query.SpatialRelationship = SpatialRelationship.esriSpatialRelContains; query.OutSpatialReference = map1.SpatialReference; queryTask.ExecuteAsync(query); } /// <summary> /// 构造查询Where条件的SQL语句 /// </summary> private void CreatQueryString() { if (QueryTypeCombox.SelectedIndex == 0) QueryString =string.Format("NAME99 = '{0}'",ExpressionTextBox.Text); else if (QueryTypeCombox.SelectedIndex == 1) QueryString = string.Format("ADCODE99 = '{0}'",ExpressionTextBox.Text); else return; } #endregion # region 调用GP服务进行栅格像元统计 private void StatisticButton_Click(object sender, RoutedEventArgs e) { if (featureSet.Features.Count <= 0) return; BusyRectangle.Visibility = Visibility.Visible; busyIndicator.IsBusy = true; AccessGPService(featureSet); } private void AccessGPService(FeatureSet featureset) { List<GPParameter> gppara = new List<GPParameter>(); //输入GP服务的参数 gppara.Add(new GPString("ZoneFiled", "OBJECTID")); gppara.Add(new GPFeatureRecordSetLayer("InputFeature", featureset)); gppara.Add(new GPString("ZonalRaster", "hunandata")); _geoprocessor.SubmitJobAsync(gppara); } private void _geoprocessor_JobCompleted(object sender, JobInfoEventArgs e) { HttpWebRequest.RegisterPrefix("http://", System.Net.Browser.WebRequestCreator.ClientHttp); Geoprocessor gp = sender as Geoprocessor; //请求GP服务的结果 gp.GetResultDataAsync(e.JobInfo.JobId, "ResultTable"); } private void _geoprocessor_GetResultDataCompleted(object sender, GPParameterEventArgs e) { MyDataGrid.ItemsSource = null; GPRecordSet gpr = e.Parameter as GPRecordSet; if (gpr.FeatureSet != null) { for (int i = 0; i < gpr.FeatureSet.Features.Count; i++) { for (int j = 2; j < gpr.FeatureSet.Features[i].Attributes.Count; j++) { //这里本文有个Bug，就是当FeatureDataGrid绑定到GraphicsLayer后， //如果修改GrapicsLayer的属性(增加或者删除)会报错，以下代码不能通过，所以这里选择了先修改再绑定 List<string> keyList = gpr.FeatureSet.Features[i].Attributes.Keys.ToList<string>(); List<object> valueList = gpr.FeatureSet.Features[i].Attributes.Values.ToList(); graphicsLayer.Graphics[i].Attributes.Add(keyList[j], valueList[j]); } } //在此绑定DataGrid，不然会出现异常 MyDataGrid.GraphicsLayer = graphicsLayer; MyDataGrid.Visibility = Visibility.Visible; //绘制地形图 if (createPlot == true) { CreatePlot(); TerrainBorder.Visibility = Visibility.Visible; } featureSet.Features.Clear(); } //等待过程 BusyRectangle.Visibility = Visibility.Collapsed; busyIndicator.IsBusy = false; } private void _geoprocessor_Failed(object sender, TaskFailedEventArgs e) { MessageBox.Show(e.Error.ToString()); } #endregion private void terrainButton_Click(object sender, RoutedEventArgs e) { myDraw.DrawMode = DrawMode.Polyline; TerrainBorder.Visibility = Visibility.Collapsed; myDraw.IsEnabled = true; createPlot = true; } private void CreatPoint(ESRI.ArcGIS.Client.Geometry.Polyline polyline,int count) { //默认沿直线构造一百个点 double xStep = (polyline.Paths[0][1].X - polyline.Paths[0][0].X) / count; double yStep = (polyline.Paths[0][1].Y - polyline.Paths[0][0].Y) / count; interval = Math.Sqrt(xStep * xStep + yStep * yStep); //清空FeatureSet便于之后的GP服务调用 if (featureSet.Features.Count > 0) { featureSet.Features.Clear(); } for (int i = 0; i < count; i++) { MapPoint mp = new MapPoint(polyline.Paths[0][0].X + i*xStep, polyline.Paths[0][0].Y + i*yStep); mp.SpatialReference = map1.SpatialReference; Graphic gPoint = new Graphic() { Symbol = new SimpleMarkerSymbol() { Color=new SolidColorBrush(Colors.Blue), Size=8, Style=SimpleMarkerSymbol.SimpleMarkerStyle.Circle }, Geometry=mp, }; featureSet.Features.Add(gPoint); graphicsLayer.Graphics.Add(gPoint); } } private void CreatePlot() { areaSeries1.Points.Clear(); areaSeries1.Points2.Clear(); plotModel.Series.Clear(); for (int i = 0; i < graphicsLayer.Graphics.Count; i++) { areaSeries1.Points.Add(new DataPoint(interval * i, Convert.ToDouble(graphicsLayer.Graphics[i].Attributes["MAX"]))); areaSeries1.Points2.Add(new DataPoint(interval * i, 0)); } plotModel.Series.Add(areaSeries1); areaSeries1.Title = "海拔"; Myplot.Model = plotModel; createPlot = false; } private void Button_MouseEnter(object sender, System.Windows.Input.MouseEventArgs e) { // TODO: Add event handler implementation here. BusyButton.Content = "取消"; } private void Button_MouseLeave(object sender, System.Windows.Input.MouseEventArgs e) { // TODO: Add event handler implementation here. BusyButton.Content = "正在计算..."; } private void BusyButton_Click(object sender, System.Windows.RoutedEventArgs e) { // TODO: Add event handler implementation here. BusyRectangle.Visibility = Visibility.Collapsed; busyIndicator.IsBusy = false; } } }
最后的MainPage.xaml代码：
View Code
<UserControl xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:oxy="clr-namespace:OxyPlot.Silverlight;assembly=OxyPlot.Silverlight" xmlns:esri="http://schemas.esri.com/arcgis/client/2009" xmlns:toolkit="http://schemas.microsoft.com/winfx/2006/xaml/presentation/toolkit" x:Class="QueryAndStatisticDemo.MainPage" mc:Ignorable="d" d:DesignHeight="760" d:DesignWidth="960" > <Grid x:Name="LayoutRoot"> <Grid.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="#FF65C0A5" Offset="0"/> <GradientStop Color="#FF1E1E1F" Offset="1"/> <GradientStop Color="#FF22555C" Offset="0.428"/> <GradientStop Color="#FF596EA1" Offset="0.681"/> </LinearGradientBrush> </Grid.Background> <Grid.RowDefinitions> <RowDefinition Height="120"/> <RowDefinition Height="*"/> </Grid.RowDefinitions> <!--Map--> <esri:Map x:Name="map1" WrapAround="True" VerticalContentAlignment="Stretch" Grid.RowSpan="2" Margin="0"> <esri:Map.Layers> <esri:LayerCollection> <esri:ArcGISDynamicMapServiceLayer Url="http://qzj-pc:6080/arcgis/rest/services/Provinces_Map/HunanMap/MapServer" /> <esri:GraphicsLayer ID="QueryResultLayer" Opacity="0.8" MouseLeftButtonDown="GraphicsLayer_MouseLeftButtonDown"/> </esri:LayerCollection> </esri:Map.Layers> </esri:Map> <!--QueryBorder--> <Border BorderBrush="Black" BorderThickness="1" Margin="8" CornerRadius="5" Background="#7F94BCE0"> <Grid> <StackPanel Orientation="Horizontal" HorizontalAlignment="Center"> <StackPanel VerticalAlignment="Center" HorizontalAlignment="Left" Margin="10,0,10,0"> <StackPanel Orientation="Horizontal" HorizontalAlignment="Left"> <Button x:Name="MorethanButton1" Content="1" Height="23" Width="48" Click="ExpressionButton_Click" /> <Button x:Name="LessthanButton2" Content="2" HorizontalAlignment="Left" Height="23" Width="48" Click="ExpressionButton_Click" /> <Button x:Name="EqualButton1" Content="3" Height="23" Width="43" Click="ExpressionButton_Click" /> </StackPanel> <StackPanel Orientation="Horizontal" HorizontalAlignment="Left"> <Button x:Name="MoreOrEButton1" Content="4" HorizontalAlignment="Left" Height="23" Width="48" Click="ExpressionButton_Click" /> <Button x:Name="LessOrEqualButton1" Content="5" HorizontalAlignment="Left" Height="23" Width="48" Click="ExpressionButton_Click" /> <Button x:Name="LessAndMoreButton1" Content="6" Height="23" Width="43" HorizontalAlignment="Left" Click="ExpressionButton_Click" /> </StackPanel> <StackPanel Orientation="Horizontal" HorizontalAlignment="Left"> <Button x:Name="LikeButton1" Content="7" HorizontalAlignment="Left" Height="23" Width="48" Click="ExpressionButton_Click" /> <Button x:Name="AndButton1" Content="8" HorizontalAlignment="Left" Height="23" Width="48" Click="ExpressionButton_Click" /> <Button x:Name="OrButton1" Content="9" Height="23" Width="43" Click="ExpressionButton_Click" /> </StackPanel> <StackPanel Orientation="Horizontal" HorizontalAlignment="Left"> <Button x:Name="NotButton1" Content="0" HorizontalAlignment="Left" Height="23" Width="48" Click="ExpressionButton_Click" /> <Button x:Name="QoutButton" Content="'" HorizontalAlignment="Left" Height="23" Width="48" ToolTipService.ToolTip="单引号" Click="QoutButton_Click" /> <Button x:Name="NoButton" Content="!" Height="23" Width="43" ToolTipService.ToolTip="非运算" Click="NoButton_Click" /> </StackPanel> </StackPanel> <StackPanel VerticalAlignment="Top" HorizontalAlignment="Center" Margin="0"> <StackPanel Orientation="Horizontal" Margin="0,10,0,0"> <TextBlock TextWrapping="Wrap" Text="查询条件：" Height="18" Margin="20,0,0,0" FontSize="14" FontWeight="Bold" Foreground="Red"/> <ComboBox x:Name="QueryTypeCombox" Height="23" Width="130" SelectedIndex="0" Margin="0,0,10,0"/> <TextBox x:Name="ExpressionTextBox" TextWrapping="Wrap" Height="27" Margin="0,5,0,0" Width="150" KeyDown="ExpressionTextBox_KeyDown"/> </StackPanel> <StackPanel Orientation="Horizontal" Margin="0,10,0,0"> <Button x:Name="ExpressionQueryButton" Content="条件查询" Height="30" Width="70" Margin="20,0,0,0" Click="ExpressionQueryButton_Click"/> <Button x:Name="SpatialQueryButton" Content="空间查询" Height="30" Width="70" Click="SpatialQueryButton_Click" Margin="10,0,0,0" /> <Button Content="绘制地形图" Height="30" x:Name="terrainButton" Width="75" Margin="20,0,0,0" Click="terrainButton_Click"/> </StackPanel> </StackPanel> <StackPanel VerticalAlignment="Center" HorizontalAlignment="Left" Margin="20,0,20,0"> <Button Width="135" Height="23" x:Name="StatisticButton" Content="地形统计" Margin="0,5,0,0" Click="StatisticButton_Click" /> <Button x:Name="ClearExpressionButton" Content="清空查询语句" Height="23" Width="135" Click="SpatialQueryButton_Click" Margin="0,10,0,0" /> <Button Width="135" Height="23" x:Name="ClearGraphicsButton" Content="清空图层" Margin="0,10,0,0" Click="ClearGraphicsButton_Click" /> </StackPanel> </StackPanel> </Grid> </Border> <!--StatisticResultForm--> <esri:FeatureDataGrid x:Name="MyDataGrid" HorizontalAlignment="Right" Margin="0,0,20,20" VerticalAlignment="Bottom" Map="{Binding ElementName=map1}" Width="400" Height="200" Grid.Column="0" Grid.Row="1" SelectionMode="Single" VerticalGridLinesBrush="#FF31D8D8" HorizontalGridLinesBrush="#FF31B1B1" RowBackground="#AA3C8A99" Visibility="Collapsed" > <esri:FeatureDataGrid.Effect> <DropShadowEffect/> </esri:FeatureDataGrid.Effect> <esri:FeatureDataGrid.Background> <LinearGradientBrush EndPoint="0.894,0.85" StartPoint="-0.076,-0.033"> <GradientStop Color="#FF56585E"/> <GradientStop Color="#FF1B8D85" Offset="1"/> </LinearGradientBrush> </esri:FeatureDataGrid.Background> </esri:FeatureDataGrid> <Border BorderThickness="1" Grid.Row="1" Height="260" HorizontalAlignment="Left" Margin="20" x:Name="TerrainBorder" VerticalAlignment="Bottom" Width="400" CornerRadius="10" Visibility="Collapsed"> <Border.Effect> <DropShadowEffect/> </Border.Effect> <oxy:Plot x:Name="Myplot" Foreground="#FFE9E5E5" > <oxy:Plot.Effect> <DropShadowEffect/> </oxy:Plot.Effect> <oxy:Plot.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="#FF0F4549" Offset="0"/> <GradientStop Color="#B266AABA" Offset="1"/> <GradientStop Color="#DA8F9EA1" Offset="0.471"/> </LinearGradientBrush> </oxy:Plot.Background> </oxy:Plot> </Border> <Rectangle x:Name="BusyRectangle" Fill="#FF454552" Stroke="Black" Grid.RowSpan="2" Opacity="0.5" Visibility="Collapsed"/> <toolkit:BusyIndicator x:Name="busyIndicator" Grid.Row="1" VerticalAlignment="Center" HorizontalAlignment="Center" IsBusy="False"> <toolkit:BusyIndicator.BusyContent> <Grid> <Button x:Name="BusyButton" Height="23" Width="199" Content="正在计算..." MouseEnter="Button_MouseEnter" MouseLeave="Button_MouseLeave" Padding="3" Click="BusyButton_Click"/> </Grid> </toolkit:BusyIndicator.BusyContent> </toolkit:BusyIndicator> </Grid> </UserControl>
最终的效果：
按县区名称查询双峰县，结果如下图所示：
正在统计双峰县的像元信息
统计结果如下图所示：
绘制一条直线
通过直线得到构造点，并进行像元统计
最后的统计结果，及地下剖面图，根据直线经过的地方来看，地形图是正确的。
在图上可以查看剖面图的数据：
空间查询，并进行统计
总结：以上的过程大致上说了一下Web端区域像元统计的过程，其中涉及到了要素查询，GP服务，Web端栅格数据作为输入数据的处理问题，OxyPlot图表控件的使用，FeatureDataGrid的数据绑定等，有些内容进行了详细的说明，有些由于时间限制就没有进行细致的说明，在此还望谅解。有什么问题可以留言反映，我一定都会逐一回复。当然程序中还有很多Bug，也没有处理，程序的结构也不是很好，代码质量也不高，希望高手勿喷，欢迎您提出宝贵的意见和分享您的解决方法。
还有需要提醒一点的是本文使用的服务都是我自己发布的服务，所以您需要自己发布程序中用到的服务。
【源码下载】
