问WPF Toolkit on Chart系列中的绑定

EN

<Border Background="White" BorderThickness="2" BorderBrush="Black" Grid.Column="1">
    <!--ContentPresenter Content="{Binding Path=FormHost}">
    </ContentPresenter-->
    <Grid>
        <chart:Chart Name="chart1">                                   
            <chart:Chart.Series>
                <chart:PieSeries Name="series1" ItemsSource="{Binding ChartItems}"
                                 IndependentValueBinding="{Binding Path=Name}"
                                 DependentValueBinding="{Binding Path=Value}"/>
            </chart:Chart.Series>
        </chart:Chart>
    </Grid>
</Border>

private ObservableCollection<ChartElement> chartItems; 
public MainWindowViewModel()
{                       
    chartItems = new ObservableCollection<ChartElement>();

    chartItems.Add(new ChartElement("da011111111111", 3));
    chartItems.Add(new ChartElement("adas111111", 490));
    chartItems.Add(new ChartElement("adas111111", 341));
    chartItems.Add(new ChartElement("adas111111", 413));
    chartItems.Add(new ChartElement("adas111111", 143));
}