Home / Community & Support / Developer Productivity Tools Forums / WPF > Chart > Chart Legend error

• James

  Posted on Feb 1, 2012 (permalink)

  I upgraded my WPF controls to version 2011.2.712.35 to fix a problem with adding the Camera Extension to a Chart for zooming.  When I did this I started getting a very odd error in a call to add a LegendItemMarkerShape to the Legend.  The chart xaml looks like this:
  
  

  <UserControl x:Class="ABC.APP.ProfileWpf.ChartControl"
               xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
               xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
               xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
               xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
               mc:Ignorable="d"
               d:DesignHeight="300" d:DesignWidth="300" xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation">
      <Grid>
          <telerik:RadChart Margin="0" Name="mChartControl">
              <telerik:RadChart.DefaultSeriesDefinition>
                  <telerik:Bar3DSeriesDefinition />
              </telerik:RadChart.DefaultSeriesDefinition>
    
              <telerik:RadChart.DefaultView>
                  <telerik:ChartDefaultView>
                      <telerik:ChartDefaultView.ChartLegend>
                          <telerik:ChartLegend Name="legend" />
                      </telerik:ChartDefaultView.ChartLegend>
                      <telerik:ChartDefaultView.ChartArea>
                          <telerik:ChartArea LegendName="legend" DimensionMode="Strict3D">
                              <telerik:ChartArea.Extensions>
                                  <telerik:CameraExtension />
                              </telerik:ChartArea.Extensions>
                          </telerik:ChartArea>
                      </telerik:ChartDefaultView.ChartArea>
                  </telerik:ChartDefaultView>
              </telerik:RadChart.DefaultView>
          </telerik:RadChart>        
      </Grid>
   and the code where I pass the marker shape looks like this:
  
  mChartControl.DefaultView.ChartArea.Legend.LegendItemMarkerShape = value;
  
  I am using VS2010 and the weird thing here is if I let the code run without inspecting the object in the QuickWatch 
  Dialog then it will exception with the error "Object reference not set to an instance of an object.".  If I 
  go ahead and inspect the mChartControl object and drill all of the way down to the Lengend object the Legend 
  object will show "+Legend{Telerik.Windows.Controls.Charting.ChartLegend Header: Items.Count:0}" that it does
  exist and the code will run as it should without exception, but if I just do a hover over the string in the 
  IDE the Legend oject will show a value of NULL and will exception.  Please let me know what is going on here
  and what can be done to correct this.  Thanks for your help out there.
  

  
  

  Reply

• Nikolay Nikolay

  Posted on Feb 6, 2012 (permalink)

  Hello James,
  
  Please, try setting the marker shape from the ChartLegend in this manner :
  

  this.RadChart1.DefaultView.ChartLegend.LegendItemMarkerShape = MarkerShape.Circle;

  
  Hope this helps.
  
  Regards,
  Nikolay
  the Telerik team

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  Reply

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