从DataContext为麻雀图WP8提供ViewModel

Question

下面是关于如何创建一个基本麻雀图的这教程。基本上包括创建一个ViewModel类和在图表的DataContext中设置ViewModel。

The ViewModel:

//Create a model
public class Model
{
    public double X { get; set; }
    public double Y { get; set; }

    public Model(double x,double y)
    {
        X = x;
        Y = y;           
    }      
}

// Create a ViewModel
public class ViewModel
{
    public ObservableCollection<Model> Collection { get; set; }
    public ViewModel()
    {
        Collection = new ObservableCollection<Model>();
        GenerateDatas();
    }
    private void GenerateDatas()
    {
        this.Collection.Add(new Model(0, 1));
        this.Collection.Add(new Model(1, 2));
        this.Collection.Add(new Model(2, 3));
        this.Collection.Add(new Model(3, 4));
    }
}

XAML:

//Use the viewmodel in the Sparrow Chart
<sparrow:SparrowChart>
   <sparrow:SparrowChart.DataContext> 
          **<local:ViewModel/>**
  </sparrow:SparrowChart.DataContext>
        <sparrow:SparrowChart.XAxis>
                <sparrow:LinearXAxis/>
        </sparrow:SparrowChart.XAxis>
        <sparrow:SparrowChart.YAxis>
                <sparrow:LinearYAxis/>
        </sparrow:SparrowChart.YAxis>
       <sparrow:LineSeries PointsSource="{Binding Collection}" XPath="X" YPath="Y"/>

​

如何定义本地：命名空间，然后在其中包含ViewModel，以便它在DataContext中运行良好？

Answer 1

将下面一行添加到窗口的XAML代码xmlns:local="clr-namespace:Here.Comes.Your.Namespace"中

在我看来

<Window x:Class="MyProgram.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:sparrow="http://sparrowtoolkit.codeplex.com/wpf"
        xmlns:local="clr-namespace:MyProgram"
        Title="My Program" Height="306" Width="736" MinWidth="680" MinHeight="440">

另外，要将用于将数据提供给SparrowChart的集合进行实际绑定，请使用ViewModel实例设置图表的DataContext。

/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public sealed partial class MainWindow
{
    ViewModel myViewModel;

    public MainWindow()
    {
        ...
        myViewModel = new ViewModel();
        mySparrowChart.DataContext = myViewModel;
    }
}

当然，斯帕罗图的控制名是mySparrowChart ( <sparrow:SparrowChart Name="mySparrowChart">)。