Update and refresh wpf chart

问题:

I'm working with chart of wpf toolkit, and I can't view the inserted data of the chart... Here is the xaml part:

<chartingToolkit:Chart  Height="352" HorizontalAlignment="Left" Name="profilo_cale_chart" Title="Profili cale" VerticalAlignment="Bottom" Width="655" FontSize="16" Margin="252,0,0,55" Visibility="Hidden"> 
   <chartingToolkit:AreaSeries DependentValuePath="Value" IndependentValuePath="Key" IsSelectionEnabled="True" ItemsSource="{Binding}" Foreground="#FF242424" Background="LightSteelBlue" />
</chartingToolkit:Chart>

And the cs: Declaration

public partial class MainWindow : Window
{ ...  
    List<KeyValuePair<DateTime, double>> valueList = new List<KeyValuePair<DateTime, double>>(); 
...

Module called when a user chose two dateTime and press a button

private void refresh_charts(DateTime dtStart, DateTime dtEnd)
{
    valueList.Clear();
    using (ModelFoosContainer mc1 = new ModelFoosContainer())
    {
        var res_mea = (from mea in mc1.MeasureSet where (mea.datetime>= dtStart && mea.datetime <= dtEnd) orderby mea.datetime descending select mea).Take(1000);
        foreach (Measure mea1 in res_mea){
            valueList.Add(new KeyValuePair<DateTime,double>(mea1.datetime, Convert.ToDouble(mea1.depth)));
        }
    }


    profilo_cale_chart.DataContext = valueList;
    //I've tried with this two but doesn't work..
    //profilo_cale_chart.Refresh();
    //this.UpdateLayout();

}

After this the chart has the right and not empty DataContext but doesn't show the values... anyone knows how can I fix it?

回答1:

Try to set name for chart series:

<chartingToolkit:AreaSeries Name="Example" DependentValuePath="Value" IndependentValuePath="Key" IsSelectionEnabled="True" ItemsSource="{Binding}" Foreground="#FF242424" Background="LightSteelBlue" />

and after that, set DataContext for AreaSeries:

Example.DataContext = valueList;

回答2:

Try change "Visibility" for Chart in xaml from

Visibility="Hidden"

to

Visibility="Visible"