WPF饼图不切分

Question

I am using PieChart control to display the two values from my database as (USED and AVAILABLE). but I get output without slicing as seen in the image below,

How to slice up the Pie Chart?

my KeyValue pair is of type . I am getting the values for my KeyValuePair from a datasource & i am retrieving using Linq to sql queries.

XAML for my Pie chart:

 <Window.Resources>
  <CollectionViewSource x:Key="ramView" Source="{Binding Path=UsageRAMs, Source={StaticResource serverView}}"/>
 </Window.Resources>

 <dvc:Chart x:Name="Ram" Background="White" Foreground="Black" Margin="950,0,92,485" Grid.Column="1" Grid.Row="1">
 <dvc:Chart.Series>
 <dvc:PieSeries ItemsSource="{Binding}"
 DependentValuePath="Available" IndependentValuePath="Used" >                               
 </dvc:PieSeries>
 </dvc:Chart.Series>
</dvc:Chart>

code behind

 private CollectionViewSource serversUsageRAMsViewSource; 
 private void Window_Loaded(object sender, RoutedEventArgs e)
    {
    var ramList = (from c in db.UsageRAMs
                  orderby c.UsageRamID descending, c.Used,c.Available,c.Total
                  select c).Take(1);
    this.serversUsageRAMsViewSource  = (CollectionViewSource)this.FindResource("ramView");
    serversUsageRAMsViewSource.Source = ramList;
   }

Answer 1

Well I guess you should have two series.

<dvc:Chart ...>
     <dvc:Chart.Series>
          <dvc:PieSeries ItemsSource="{Binding}" DependentValuePath="Available" />
          <dvc:PieSeries ItemsSource="{Binding}" DependentValuePath="Used" />
     </dvc:Chart.Series>
</dvc:Chart>   

Disclaimer - I didn't test it, but that's what I would try.