使用Visifire+ArcGIS API for Silverlight实现Graphic信息的动态图表显示

http://www.cnblogs.com/potential/archive/2013/05/06/3063316.html

点击其中的一个例子，然后点击Live Updates,就可看到数据更新时的过渡效果。但是蛋疼的博客园，不知道为什么，我插入了我原始的xap文件，过渡效果却没有了，每次更新数据时，曲线直接就出来了(中间没有过渡行为)，开始的时候以为是上传后xap文件有可能发生了变化，或者进行压缩什么的，或者浏览器解析什么的，于是我把上传到博客园的xap文件又下载下来，然后嵌入到一个htm页面中，发现还是有过度效果的，但是为什么在博客园的日志中就没有呢？整了好久还是没有整明白，求解释！

 

下面来看看具体实现的过程吧：

首先需要添加SLVisifire.Charts，FJ.Core的引用。然后开始我们正式的工作：

1.定义一个Chart,该Chart即为显示的图表，以及定义一个Timer,用于定时刷新数据。

        Chart chart;                                               Random rand = new Random(DateTime.Now.Millisecond);            System.Windows.Threading.DispatcherTimer timer = new         System.Windows.Threading.DispatcherTimer();

2.定义一个方法：CreateChart实例化Chart,并完成Chart的相关设置(如：高，宽，曲线样式等等)

        /// <summary>        /// Function to create a Visifire Chart        /// </summary>        public void CreateChart()        {            try            {                // Create a new instance of a Chart                chart = new Chart();                //添加X,Y坐标的描述                Axis axisX = new Axis()                {                    Title = "月份",                    FontSize = 18,                };                chart.AxesX.Add(axisX);                Axis axisY = new Axis()                {                    Title = "实时监测值",                    FontSize = 16,                };                chart.AxesY.Add(axisY);                // 设置图表的高宽                chart.Width = 640;                chart.Height = 300;                //Line数据更新时的过渡效果                chart.AnimatedUpdate = true;                // 定义DatatSeries实例，即一条曲线                DataSeries dataSeries1 = new DataSeries();                DataSeries dataSeries2 = new DataSeries();                //只有当Series的个数大于等于2个时Lenged才会生效                dataSeries1.LegendText = "CO2";                dataSeries2.LegendText = "SO2";                // 设置DataSeries样式                dataSeries1.RenderAs = RenderAs.Spline;                dataSeries2.RenderAs = RenderAs.Spline;                // 定义数据点                DataPoint dataPoint1;                DataPoint dataPoint2;                for (int i = 1; i <= 12; i++)                {                    // 实例化数据点                    dataPoint1= new DataPoint();                    dataPoint2 = new DataPoint();                    //设置数据值                    dataPoint1.YValue = rand.Next(0, 99);                    dataPoint2.YValue = rand.Next(0, 99);                    //设置X轴显示名称                    dataPoint1.AxisXLabel = string.Format("{0} 月", i);                    dataPoint2.AxisXLabel = string.Format("{0} 月", i);                    // 添加数据点                    dataSeries1.DataPoints.Add(dataPoint1);                    dataSeries2.DataPoints.Add(dataPoint2);                }                // 将DataSeries(曲线)添加到Chart中                chart.Series.Add(dataSeries1);                chart.Series.Add(dataSeries2);                // 注册Chart Loaded事件,在该事件中设置Timer的间断值及注册Timer Tick事件                chart.Loaded += new RoutedEventHandler(chart_Loaded);            }            catch (Exception ex)            {                MessageBox.Show(ex.ToString());            }        }

3.我们看到在创建Chart中注册了Loaded事件，在该事件的完成函数我们设置Timer的间断值及注册Timer Tick事件

     void chart_Loaded(object sender, RoutedEventArgs e)        {            timer.Tick += new EventHandler(timer_Tick);            timer.Interval = new TimeSpan(0, 0, 0, 0, 2000);        }

        /// <summary>        /// Event handler for Tick event of Dispatcher Timer        /// </summary>        /// <param name="sender">System.Windows.Threading.DispatcherTimer</param>        /// <param name="e">EventArgs</param>        void timer_Tick(object sender, EventArgs e)        {            for (Int32 i = 0; i < 12; i++)            {                // 更新曲线数据                chart.Series[0].DataPoints[i].YValue = rand.Next(0, 99);                 chart.Series[1].DataPoints[i].YValue = rand.Next(20, 80);             }        }

4.这里我们再写一个方法：AddChartToMapLayer，该方法用来将Chart添加到地图中

        /// <summary>        /// Add Chart to Map        /// </summary>        /// <param name="chart">Chart</param>        /// <param name="position">Position</param>        public void AddChartToMapLayer(Chart chart, Graphic position)        {            ElementLayer chartlayer = new ElementLayer();            chartlayer.ID = "ChartLayer";            chartlayer.Opacity = 1;            if (Map.Layers["ChartLayer"] != null)            {                Map.Layers.Remove(Map.Layers["ChartLayer"]);            }            chart.Titles.Add(new Title()            {                Text=string.Format("City: {0}",position.Attributes["CITY_NAME"].ToString ())            });            //获得Graphic的中心坐标            ESRI.ArcGIS.Client.Geometry.Geometry geometry=position.Geometry;            MapPoint mapPoint=new MapPoint ((geometry.Extent.XMax+geometry.Extent.XMin)/2,(geometry.Extent.YMax+geometry.Extent.YMin)/2);                      //获得图层X,Y方向对应的比例            double cell_X = (Map.Extent.XMax - Map.Extent.XMin) / Map.ActualWidth;            double cell_Y = (Map.Extent.YMax - Map.Extent.YMin) / Map.ActualHeight;            //Chart的宽度为500所以，Chart的中心则位于宽度等于250的位置，将Chart向右移动，以防Chart覆盖Graphic            Envelope extent = new Envelope(mapPoint.X + (320 + 20) * cell_X, mapPoint.Y, mapPoint.X + (320 + 20) * cell_X, mapPoint.Y);            //设置ElementLayer的外包范围            ElementLayer.SetEnvelope(chart, extent);            chartlayer.Children.Add(chart);            Map.Layers.Add(chartlayer);        }

现在准备工作已经完成，下面就调用这些方法来实现上述的功能，我们大体的功能过程是：

当鼠标移入Graphic是就显示其对应的Chart,移除的移除Chart,这里我们注册一下FeatureLayer的MouseEnter和MouseLeave事件就行，我们再后台的XAML中注册这两个事件。

     <esri:FeatureLayer ID="MyFeatureLayer"                    Url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer/0"                     Where="POP1990 > 500000"                                       MouseEnter="FeatureLayer_MouseEnter"                                       MouseLeave="FeatureLayer_MouseLeave"                                       Renderer="{StaticResource MySimplePointRenderer}"/>

最后在后台添加如下代码：

   private void FeatureLayer_MouseEnter(object sender, GraphicMouseEventArgs e)        {            //绘制Chart            CreateChart();            //将Chart添加到Map            AddChartToMapLayer(chart, e.Graphic);            //启动Timer,定时刷新数据            timer.Start();        }        private void FeatureLayer_MouseLeave(object sender, GraphicMouseEventArgs e)        {            //停止Timer            timer.Stop();            //移除ElementLayer            if (Map.Layers["ChartLayer"] != null)            {                Map.Layers.Remove(Map.Layers["ChartLayer"]);            }        }

后台的XAML代码：

View Code

<UserControl x:Class="SilverlightChartDemo.MainPage"    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"              xmlns:vsm="clr-namespace:System.Windows;assembly=System.Windows"    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"   xmlns:vc="clr-namespace:Visifire.Charts;assembly=SLVisifire.Charts"    mc:Ignorable="d"    d:DesignHeight="300" d:DesignWidth="400" xmlns:esri="http://schemas.esri.com/arcgis/client/2009">    <Grid x:Name="LayoutRoot" Background="White">        <Grid.Resources>            <esri:SimpleRenderer x:Key="MySimplePointRenderer">                <esri:SimpleRenderer.Symbol>                    <esri:SimpleMarkerSymbol Size="15" Style="Circle">                        <esri:SimpleMarkerSymbol.ControlTemplate>                            <ControlTemplate>                                <Grid x:Name="RootElement" RenderTransformOrigin="0.5,0.5" Width="15" Height="15">                                    <Grid.RenderTransform>                                        <ScaleTransform x:Name="customEnlargeRotatingMarkerSymbolScale" ScaleX="1" ScaleY="1" />                                    </Grid.RenderTransform>                                    <Grid.Resources>                                        <DropShadowEffect x:Key="customEnlargeRotatingMarkerSymbolEffect" />                                    </Grid.Resources>                                    <vsm:VisualStateManager.VisualStateGroups>                                        <vsm:VisualStateGroup x:Name="CommonStates">                                            <vsm:VisualState x:Name="Normal">                                                <Storyboard>                                                    <DoubleAnimation BeginTime="00:00:00" Storyboard.TargetName="customEnlargeRotatingMarkerSymbolScale" Storyboard.TargetProperty="ScaleX" To="1" Duration="0:0:0.2" />                                                    <DoubleAnimation BeginTime="00:00:00" Storyboard.TargetName="customEnlargeRotatingMarkerSymbolScale" Storyboard.TargetProperty="ScaleY" To="1" Duration="0:0:0.2" />                                                    <DoubleAnimation BeginTime="00:00:00" Storyboard.TargetName="customEnlargeRotatingMarkerSymbolRotate" Storyboard.TargetProperty="Angle" To="360" Duration="0:0:0.2" />                                                    <DoubleAnimation BeginTime="00:00:00" Storyboard.TargetName="ellipse" Storyboard.TargetProperty="(UIElement.Effect).(DropShadowEffect.ShadowDepth)" To="2" Duration="0:0:0.2" />                                                </Storyboard>                                            </vsm:VisualState>                                            <vsm:VisualState x:Name="MouseOver">                                                <Storyboard>                                                    <DoubleAnimation BeginTime="00:00:00" Storyboard.TargetName="customEnlargeRotatingMarkerSymbolScale" Storyboard.TargetProperty="ScaleX" To="2" Duration="0:0:0.2" />                                                    <DoubleAnimation BeginTime="00:00:00" Storyboard.TargetName="customEnlargeRotatingMarkerSymbolScale" Storyboard.TargetProperty="ScaleY" To="2" Duration="0:0:0.2" />                                                    <DoubleAnimation BeginTime="00:00:00" Storyboard.TargetName="customEnlargeRotatingMarkerSymbolRotate" Storyboard.TargetProperty="Angle" To="0" Duration="0:0:0.2" />                                                    <DoubleAnimation BeginTime="00:00:00" Storyboard.TargetName="ellipse" Storyboard.TargetProperty="(UIElement.Effect).(DropShadowEffect.ShadowDepth)" To="5" Duration="0:0:0.2" />                                                </Storyboard>                                            </vsm:VisualState>                                        </vsm:VisualStateGroup>                                    </vsm:VisualStateManager.VisualStateGroups>                                    <Ellipse x:Name="ellipse" Width="15" Height="15" Fill="Green" Stroke="White" StrokeThickness="2" HorizontalAlignment="Center" VerticalAlignment="Center" Effect="{StaticResource customEnlargeRotatingMarkerSymbolEffect}"></Ellipse>                                    <Canvas x:Name="RotateCanvas" HorizontalAlignment="Left" VerticalAlignment="Top" Width="15" Height="15" RenderTransformOrigin="0.5,0.5">                                        <Canvas.Clip>                                            <EllipseGeometry RadiusX="7.5" RadiusY="7.5" Center="7.5,7.5" />                                        </Canvas.Clip>                                        <Canvas.RenderTransform>                                            <RotateTransform x:Name="customEnlargeRotatingMarkerSymbolRotate" Angle="360" />                                        </Canvas.RenderTransform>                                        <Line Stroke="White" StrokeThickness="2" X1="0" Y1="0" X2="15" Y2="15" />                                        <Line Stroke="White" StrokeThickness="2" X1="0" Y1="15" X2="15" Y2="0" />                                    </Canvas>                                </Grid>                            </ControlTemplate>                        </esri:SimpleMarkerSymbol.ControlTemplate>                    </esri:SimpleMarkerSymbol>                </esri:SimpleRenderer.Symbol>            </esri:SimpleRenderer>        </Grid.Resources>        <esri:Map Background="White" HorizontalAlignment="Stretch" Margin="0" Grid.ColumnSpan="3" Name="Map" VerticalAlignment="Stretch" WrapAround="True" Extent="-15000000,2000000,-7000000,8000000">            <esri:Map.Layers>                <esri:LayerCollection>                    <esri:ArcGISTiledMapServiceLayer Url="http://www.arcgisonline.cn/ArcGIS/rest/services/ChinaOnlineCommunity/MapServer" />                    <esri:FeatureLayer ID="MyFeatureLayer"                    Url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer/0"                     Where="POP1990 > 500000"                                       MouseEnter="FeatureLayer_MouseEnter"                                       MouseLeave="FeatureLayer_MouseLeave"                                       Renderer="{StaticResource MySimplePointRenderer}"/>                </esri:LayerCollection>            </esri:Map.Layers>        </esri:Map>           </Grid></UserControl>

这样我们便实现了上述的效果。

 

需要注意的几点：

1.Chart控件第一次加载数据的动画效果(一个点一个点添加)，只能使用一次，也就是实例化Chart，加载数据时会有这样的效果,之后更新Chart控件的数据不会有类似第一次加载Chart时显示曲线动画效果，而是上面说的过渡效果。

2.注意设置Chart的AnimatedUpdate属性为True,否则数据更新时绘制曲线没有过渡的效果

3.将Chart作为ElementLayer添加到地图中，注意设置ElementLayer的显示位置。

 

 总结：

 以上的过程数据都是用Timer组件来定时生成的，当然这里也可以扩展，比如你的数据也可以是通过SQL查询得到。此外，本例没有用到数据绑定，这是因为本文的Chart是动态生成的，每次选择Graphic时都会重新生成Chart.所以没有用数据绑定。当然如果你的Chart是写死的(实例化一次)，或者定义在后台的xaml中，那么建议您选择数据绑定的方式，数据绑定的方式也很简单，例如在XAML定义如下的Chart(详见Visifire documentation):

<vc:Chart Name="MyChart" Width="500" Height="300" Theme="Theme1">    <vc:Chart.Series>        <vc:DataSeries RenderAs="Column" DataSource="{Binding}">            <vc:DataSeries.DataMappings>                <vc:DataMapping MemberName="XValue" Path="Key"></vc:DataMapping>                <vc:DataMapping MemberName="YValue" Path="Value"></vc:DataMapping>            </vc:DataSeries.DataMappings>        </vc:DataSeries>    </vc:Chart.Series></vc:Chart>

在后台添加如下代码：

public partial class Page : UserControl{    public Page()    {        InitializeComponent();         for (int i = 0; i < 10; i++)        {            values.Add(new KeyValuePair<double,double>(i, i + 1));        }                    MyChart.DataContext = values;    }    Random rand = new Random();    ObservableCollection<KeyValuePair<Double, Double>> values = new ObservableCollection<KeyValuePair<double, double>>();}

这样便可以实现Chart曲线的数据绑定。

PS:有那么一段时间没有用Visifire了，很多又忘记了，以上算是自己的一个总结，同时很多人也问个类似的效果怎么做，在此和大家分享一下，鉴于时间和知识的关系，疏漏和错误在所难免，还望各位指正。

 //关于解决地图缩放时Chart偏移的问题。

1.注册Map的ExtentChanging事件，然后在事件完成函数中重新设定Elmentlayer的Envelop,代码如下：

        private void Map_ExtentChanging(object sender, ExtentEventArgs e)        {            double cell_X = (Map.Extent.XMax - Map.Extent.XMin) / Map.ActualWidth;            ESRI.ArcGIS.Client.Geometry.Geometry geometry = selectedGraphic.Geometry;            MapPoint mapPoint = new MapPoint((geometry.Extent.XMax + geometry.Extent.XMin) / 2, (geometry.Extent.YMax + geometry.Extent.YMin) / 2);            Envelope extent = new Envelope(mapPoint.X + (320 + 20) * cell_X, mapPoint.Y, mapPoint.X + (320 + 20) * cell_X, mapPoint.Y);            Chart Mychart = chartlayer.Children[0] as Chart;            ElementLayer.SetEnvelope(Mychart, extent);        }