使用Silverlight Toolkit绘制图表(上)--柱状图 推荐

Silverlight Toolkit提供了绘制柱状图(Column,Bar)，饼图(Pie)，折线图(Line), 散点图(Scatter)等控件。我们可以很方便的将已有的数据源绑定到相应图形控件上，设置好相应的X,Y轴显示样式和数据字段之后就大功告成了，同时其还支持图形的定时加载刷新，图形的动态加载动画效果。今天就先以柱状图为例，简要的总结一下如何使用该控件来显示我们的数据。

首先，我们需要创建一个Silverlight项目，命名：DataVisualization。

然后我们使用WCF方式发布数据源信息，这里我们创建一个"Silverlight功能的WCF"，并将其命名为： DataService.svc



接着将下面的代码拷贝到该类文件中：

public class EmployeeInfo
{
public int EmployeeID { set; get; }
public string EmployeeName { set; get; }
public int Salary { set; get; }
public int[] Cost { get; set; }
public string City { set; get; }
}

[ServiceContract(Namespace = "")]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
public class DataService
{
[OperationContract]
public List<EmployeeInfo> GetEmployeeList()
{
List<EmployeeInfo> employeeList = new List<EmployeeInfo>();
employeeList.Add(new EmployeeInfo { EmployeeID = 1, EmployeeName = "张三", Salary = 1000, City = "合肥" });
employeeList.Add(new EmployeeInfo { EmployeeID = 2, EmployeeName = "李四", Salary = 1500, City = "天津" });
employeeList.Add(new EmployeeInfo { EmployeeID = 3, EmployeeName = "王五", Salary = 2000, City = "上海" });
employeeList.Add(new EmployeeInfo { EmployeeID = 4, EmployeeName = "赵六", Salary = -800, City = "北京" });
employeeList.Add(new EmployeeInfo { EmployeeID = 5, EmployeeName = "尤七", Salary = 2100, City = "武汉" });
employeeList.Add(new EmployeeInfo { EmployeeID = 6, EmployeeName = "马八", Salary = 2300, City = "海口" });
return employeeList;
}
}

这里数据源我们就创建完成了，它将会返回6个雇员信息。

下面我们往该Silverlight应用的Xaml文件上拖（或手工声明）一个Chart控件，如下：

<charting:Chart Title="员工薪水" x:Name="EmployeeChart"></charting:Chart>

我们看到在该控件上我们指定了Title信息，该信息会显示在图表的最上方。

下面开始编写CS代码。

1.首先我们向该Silverlight应用中添加对刚才声明的WCF的引用。

2.使用WCF生成的客户端类来获取相应的数据源，代码如下：

void LoadWcfData()
{
dataServiceClient.GetEmployeeListCompleted += new EventHandler<GetEmployeeListCompletedEventArgs>(dataServiceClient_GetEmployeeListCompleted);
dataServiceClient.GetEmployeeListAsync();
}

3.将WCF返回的数据源信息绑定到相应的图形控件上，并初始化该控件的相应信息，如下：

void dataServiceClient_GetEmployeeListCompleted(object sender, GetEmployeeListCompletedEventArgs e)
{
ObservableCollection<EmployeeInfo> employeeList = e.Result;

Action<Chart> chartModifier = (chart) =>
{
Axis dateAxis = new Axis { Orientation = AxisOrientation.Horizontal, Title = "雇员名称", FontStyle = FontStyles.Normal, FontSize = 12f, ShowGridLines = true};
EmployeeChart.Axes.Add(dateAxis);
Axis valueAxis = new Axis { Orientation = AxisOrientation.Vertical, Title = "薪水", Minimum = -1000, Maximum = 3000, ShowGridLines = true};
EmployeeChart.Axes.Add(valueAxis);
};
chartModifier(EmployeeChart);

ColumnSeries series = new ColumnSeries();
series.ItemsSource = employeeList;
series.IndependentValueBinding = new System.Windows.Data.Binding("EmployeeName");
series.DependentValueBinding = new System.Windows.Data.Binding("Salary");
series.Title = "薪水";
EmployeeChart.Series.Add(series);
}

在上面的代码中我们创建了Axis对象用以将X,Y轴的描述信息绑定到指定的图形控件上，然后将我们的指定数据源绑定到该图形控件的ItemsSource属性上，最后再绑定两个座标轴要显示的相应数据：
X轴: series.IndependentValueBinding = new System.Windows.Data.Binding("EmployeeName");

Y轴: series.DependentValueBinding = new System.Windows.Data.Binding("Salary");

下面我们来看一下最终的显示效果，如下图所示：



大家看到，在Y轴上我们既显示了正轴也显示了负轴，这就是通过Minimum = -1000, Maximum = 3000这一行设置实现的。

还不错了，到这里我们只是简要的领略了一个图形控件的基本功能。接着我们再了解一下它还有那些更高级的使用技巧。
首先是图形的定时加载刷新，要实现这个演示，我们需要一个实时变化的数据源，以便当我们定时刷新控件时能显示不同的数据信息。所以我们要在WCF中创建一个这样的数据源：
[OperationContract]
public List<EmployeeInfo> GetEmployeeDynamicList()
{
Random random = new Random();
List<EmployeeInfo> employeeList = new List<EmployeeInfo>();
employeeList.Add(new EmployeeInfo { EmployeeID = 1, EmployeeName = "张三", Salary = random.Next(500, 3000), City = "合肥" });
employeeList.Add(new EmployeeInfo { EmployeeID = 2, EmployeeName = "李四", Salary = random.Next(500, 3000), City = "天津" });
employeeList.Add(new EmployeeInfo { EmployeeID = 3, EmployeeName = "王五", Salary = random.Next(500, 3000), City = "上海" });
employeeList.Add(new EmployeeInfo { EmployeeID = 4, EmployeeName = "赵六", Salary = random.Next(500, 3000), City = "北京" });
employeeList.Add(new EmployeeInfo { EmployeeID = 5, EmployeeName = "尤七", Salary = random.Next(500, 3000), City = "武汉" });
employeeList.Add(new EmployeeInfo { EmployeeID = 6, EmployeeName = "马八", Salary = random.Next(500, 3000), City = "海口" });
return employeeList;
}

大家看到，这里使用了Random来模拟一个动态数据源信息，其生成的随机数介于500-3000之间，那么接下来，我们再Silverlight的XAML上创建这样一个Chart对象，用以显示该动态数据源信息，如下：

<charting:Chart Title="动态员工薪水" x:Name="DynamicEmployeeChart" />

接着就是相应的CS代码了，这里为了方便起见，这里直接使用DispatcherTimer来定时(3秒)获取相应的数据源信息，如下：

void LoadDynamicData()
{
System.Windows.Threading.DispatcherTimer dispatcherTimer = new System.Windows.Threading.DispatcherTimer();
dispatcherTimer.Interval = TimeSpan.FromSeconds(3);
dispatcherTimer.Tick += delegate
{
dataServiceClient.GetEmployeeDynamicListCompleted += new EventHandler<GetEmployeeDynamicListCompletedEventArgs>(dataServiceClient_GetEmployeeDynamicListCompleted);
dataServiceClient.GetEmployeeDynamicListAsync();
};
dispatcherTimer.Start();
}

接着就是初始化相应的图形控件并绑定相应的数据源了，代码与上面的CS代码相似，如下：

void dataServiceClient_GetEmployeeDynamicListCompleted(object sender, GetEmployeeDynamicListCompletedEventArgs e)
{
ObservableCollection<EmployeeInfo> employeeList = e.Result;
DynamicEmployeeChart.Axes.Clear();
DynamicEmployeeChart.Series.Clear();
Action<Chart> chartModifier = (chart) =>
{
Axis dateAxis = new Axis { Orientation = AxisOrientation.Horizontal, Title = "雇员名称", FontStyle = FontStyles.Normal, FontSize = 12f, ShowGridLines = true };
DynamicEmployeeChart.Axes.Add(dateAxis);
Axis valueAxis = new Axis { Orientation = AxisOrientation.Vertical, Title = "薪水", Minimum = 0, Maximum = 3000, ShowGridLines = true };
DynamicEmployeeChart.Axes.Add(valueAxis);
};
chartModifier(DynamicEmployeeChart);

ColumnSeries series = new ColumnSeries();
series.ItemsSource = employeeList;
series.IndependentValueBinding = new System.Windows.Data.Binding("EmployeeName");
series.DependentValueBinding = new System.Windows.Data.Binding("Salary");
series.Title = "薪水";
DynamicEmployeeChart.Series.Add(series);
}

好了，这里我们看一下最终的运行效果，首先是刚启动运行时的截图：



然后是三秒之后的运行截图：



到这里还不算完，因为该控件还支持数据的分组显示，比如说如果我们的数据中有数组类型的字段信息，该控件是以数组为单位（数组长度就是图表的列信息）。这个有些难以理解，下面就以一个示例来加以说明。
首先，我们要创建一个具有数组类型字段的数据源，如下：
[OperationContract]
public List<EmployeeInfo> GetMultiSeriesEmployeeList()
{
List<EmployeeInfo> employeeList = new List<EmployeeInfo>();
employeeList.Add(new EmployeeInfo { EmployeeID = 1, EmployeeName = "张三", Salary = 1000, Cost = new int[] { 100, 160 } });
employeeList.Add(new EmployeeInfo { EmployeeID = 2, EmployeeName = "李四", Salary = 1500, Cost = new int[] { 260, 200 } });
employeeList.Add(new EmployeeInfo { EmployeeID = 3, EmployeeName = "王五", Salary = 2000, Cost = new int[] { 360, 330 } });
employeeList.Add(new EmployeeInfo { EmployeeID = 4, EmployeeName = "赵六", Salary = 800, Cost = new int[] { 160, 430 } });
employeeList.Add(new EmployeeInfo { EmployeeID = 5, EmployeeName = "尤七", Salary = 2100, Cost = new int[] { 560, 530 } });
employeeList.Add(new EmployeeInfo { EmployeeID = 6, EmployeeName = "马八", Salary = 2300, Cost = new int[] { 660, 600 } });
return employeeList;
}

大家看到了，在该数据源中的Cost属性即是数据类型字段，该字段记录了雇员的交费信息：第一项为“住房公积金”，第二项为“个人养老金”。

下面我们就来看一下该如何绑定这类数据源信息。

首先在XAML中创建该图表控件，如下：

<charting:Chart Title="MultiSeries" x:Name="MultiSeries" MouseLeftButtonDown="OnMouseLeftButtonDown"/>

大家看到这里我们还绑定了鼠标单击事件，该事件主要用于稍后演示图表的动态效果，这里先行略过:)

接着就是我们的CS代码了，首先是获取数据源：

void LoadMultiSeries()
{
dataServiceClient.GetMultiSeriesEmployeeListCompleted += new EventHandler<GetMultiSeriesEmployeeListCompletedEventArgs>(dataServiceClient_GetMultiSeriesEmployeeListCompleted);
dataServiceClient.GetMultiSeriesEmployeeListAsync();
}

然后是相应的控件初始化和数据绑定代码：

void dataServiceClient_GetMultiSeriesEmployeeListCompleted(object sender, GetMultiSeriesEmployeeListCompletedEventArgs e)
{
ObservableCollection<EmployeeInfo> employeeList = e.Result;

Action<Chart> chartModifier = (chart) =>
{
Axis dateAxis = new Axis { Orientation = AxisOrientation.Horizontal, Title = "注 1:住房公积金 2:个人养老金", FontStyle = FontStyles.Normal, FontSize = 14f, ShowGridLines = true };
MultiSeries.Axes.Add(dateAxis);

Axis valueAxis = new Axis { Orientation = AxisOrientation.Vertical, Title = "税金", Minimum = 0, Maximum = 800, ShowGridLines = true };
MultiSeries.Axes.Add(valueAxis);
};
chartModifier(MultiSeries);

foreach (EmployeeInfo itemsSource in employeeList)
{
ColumnSeries series = new ColumnSeries();
series.ItemsSource = itemsSource.Cost;
series.DependentValueBinding = null;
series.IndependentValueBinding = null;
series.Title = itemsSource.EmployeeName + " ID:" + itemsSource.EmployeeID;
series.AnimationSequence = AnimationSequence.FirstToLast;
MultiSeries.Series.Add(series);
}
}

这里我们看到在控件的数据源绑定上与前两个DEMO存在一定的差异。因为每个雇员的交费字段本身就是一个数组（整形），所以这里将该交费字段直接绑定到了ColumnSeries的ItemsSource属性上。同时将ColumnSeries 的属性 DependentValueBinding，IndependentValueBinding分别设置为null。这里给该ColumnSeries的动态显示效果设置成了AnimationSequence.FirstToLast。下面我们会看到显示效果，而相应的鼠标单击事件代码摘自TOOKIT的代码示例包，这里就不多加解释了。下面是相应的显示效果：



当我们在图表上单击鼠标时，显示效果如下：





等图表全被隐去时，这时我们再单击鼠标，图表会依次再显示出来。

除了数据动态加载，Chart还支持数据的静态绑定，如下面的XAML代码即是初始并绑定一个已存在的数据源：

<charting:Chart Title="Xaml绑定" x:Name="FunctionSeriesSample" MouseLeftButtonDown="OnMouseLeftButtonDown">
<charting:Chart.Series>
<charting:ColumnSeries
Title="人口" AnimationSequence="FirstToLast"
ItemsSource="{Binding PugetSound, Source={StaticResource City}}"
IndependentValueBinding="{Binding Name}"
DependentValueBinding="{Binding Population}"/>
</charting:Chart.Series>
<charting:Chart.Axes>
<charting:Axis AxisType="Category" Title="城市" Orientation="Horizontal" FontStyle="Italic"/>
<charting:Axis AxisType="Linear" Title="人口" Orientation="Vertical" Minimum="0" Maximum="600000" Interval="100000" ShowGridLines="True" FontStyle="Italic"/>
</charting:Chart.Axes>
</charting:Chart>

而数据源是在程序中直接写死的，如下：




Code




/**//// <summary>


/// City business object used for charting samples.


/// </summary>


public class City






{




/**//// <summary>


/// Gets or sets the name of the city.


/// </summary>




public int ID

{ get; set; }






/**//// <summary>


/// Gets or sets the name of the city.


/// </summary>




public string Name

{ get; set; }






/**//// <summary>


/// Gets or sets the population of the city.


/// </summary>




public int Population

{ get; set; }






/**//// <summary>


/// Initializes a new instance of the City class.


/// </summary>


public City()






{


}






/**//// <summary>


/// Returns a string that represents the current object.


/// </summary>


/// <returns>A string that represents the current object.</returns>


public override string ToString()






{


return Name;


}






/**//// <summary>


/// Gets a collection of cities in the Puget Sound area.


/// </summary>


public static ObjectCollection PugetSound






{


get






{


ObjectCollection pugetSound = new ObjectCollection();




pugetSound.Add(new City

{ Name = "张庄", Population = 312344, ID = 1 });




pugetSound.Add(new City

{ Name = "李庄", Population = 411212, ID = 2 });




pugetSound.Add(new City

{ Name = "赵庄", Population = 261391, ID = 3 });




pugetSound.Add(new City

{ Name = "马家河子", Population = 530022, ID = 4 });


return pugetSound;


}


}


}

到这里，有关柱状图的主要功能介绍的差不多了，但如果开发过相应图表功能的朋友会发现，之前的DEMO显示的都是垂直的柱状图，但很多的网站上显示的都是水平方向的柱状图，比如说投票功能等，其实Chart实现这个功能非常简要，只要在我们原有的CS代码基础上做很少的改动即可实现，这里以上面的第一个DEMO为例，看一下如何进行改造：
下面是其dataServiceClient_GetEmployeeListCompleted方法的改造后的代码：

void dataServiceClient_GetEmployeeListCompleted(object sender, GetEmployeeListCompletedEventArgs e)
{
ObservableCollection<EmployeeInfo> employeeList = e.Result;

Action<Chart> chartModifier = (chart) =>
{
Axis dateAxis = new Axis { Orientation = AxisOrientation.Vertical, Title = "雇员名称", FontStyle = FontStyles.Normal, FontSize = 12f, ShowGridLines = true };
EmployeeChart.Axes.Add(dateAxis);
Axis valueAxis = new Axis { Orientation = AxisOrientation.Horizontal, Title = "薪水", Minimum = -1000, Maximum = 3000, ShowGridLines = true};
EmployeeChart.Axes.Add(valueAxis);
};
chartModifier(EmployeeChart);

BarSeries series = new BarSeries();
series.ItemsSource = employeeList;
series.IndependentValueBinding = new System.Windows.Data.Binding("EmployeeName");
series.DependentValueBinding = new System.Windows.Data.Binding("Salary");
EmployeeChart.Series.Add(series);
}

在这里，我们看到了之前所设置的X,Y轴在AxisOrientation属性上被做了交换设置。而接着的ColumnSeries对象也被替换成了BarSeries。这样我们就完成了相应的改造(更多信息参见DEMO源码BarSample)。
其它的DEMO只要参照一下上面所说的替换方式替换一下即可，最终我们看一个显示效果，如下图所示：



好了，今天的内容就先到这里了，源码下载，请点击这里。

原文链接:]http://daizhj.blog.51cto.com/285189/129472
作者: daizhj, 代震军
Tags: silverlight,chart,图表,柱状图,Column,Bar,饼图,Pie,折线图,Line,散点图,Scatter
网址: ]http://daizhj.blog.51cto.com/

在微软的Silverlight 开源控件项目: Silverlight Toolkit