How to Display Legend from Data

[Michel]

I am trying to display the MaterialName values in the Legend...

The Chart controls creates a line for each MaterialName in the list but I cannot get the Legend to display those names...

All the examples I found use static Legend captions.

I am using this ItemSource:

public class ForecastValue
{
    public string MaterialName { get; set; }
    public double Period { get; set; }
    public double Quantity { get; set; }
}

This is the XAML code:

<telerik:RadChart x:Name="EquipmentDistribution" ItemsSource="{Binding ForecastValueList}" >
    <telerik:RadChart.DefaultView >
        <telerik:ChartDefaultView >
            <telerik:ChartDefaultView.ChartLegend>
                <telerik:ChartLegend DisplayMemberPath="MaterialName" />
            </telerik:ChartDefaultView.ChartLegend>
            <telerik:ChartDefaultView.ChartArea>
                <telerik:ChartArea OverridesDefaultStyle="False" EnableAnimations="False">
                    <telerik:ChartArea.AxisY>
                        <telerik:AxisY Title="Quantity"/>
                    </telerik:ChartArea.AxisY>
                    <telerik:ChartArea.AxisX>
                        <telerik:AxisX Title="Periods"/>
                    </telerik:ChartArea.AxisX>
                </telerik:ChartArea>
            </telerik:ChartDefaultView.ChartArea>
        </telerik:ChartDefaultView>
    </telerik:RadChart.DefaultView>
    <telerik:RadChart.SeriesMappings>
        <telerik:SeriesMapping LegendLabel="MaterialName">
            <telerik:SeriesMapping.SeriesDefinition>
                <telerik:LineSeriesDefinition LegendDisplayMode="SeriesLabel" />
            </telerik:SeriesMapping.SeriesDefinition>
            <telerik:ItemMapping DataPointMember="LegendLabel" FieldName="MaterialName"/>
            <telerik:ItemMapping DataPointMember="XValue" FieldName="Period"/>
            <telerik:ItemMapping DataPointMember="YValue" FieldName="Quantity" />
        </telerik:SeriesMapping>
    </telerik:RadChart.SeriesMappings>
</telerik:RadChart>

[Nikolay]

Hello Michel,

It appears that the Legend has not been associated with the ChartArea, which is why you do not get the items displayed. Please, find attached a sample application, that we have prepared to simulate a scenario similar to yours.

Hope this helps.

Regards,
Nikolay
the Telerik team

[Michel]

Thanks !

It is now displaying the Material names. Great, but if I have 12 values for one Material name, I see 12 times the same Material name in the legend...

My scenario is that I may have 2 - 5 Materials with multiple values.

Do I have to present the data in another way ? Or is it just a different setting in the Chart control ?

Thanks again,

Michel

[Nikolay]

Hello Michel,

In case you need to have each material as a separately defined series, then you would need one series mapping for each material. Please, find attached a slightly modified version of the original application, which demonstrates how you can achieve the desired behavior.

Greetings,
Nikolay
the Telerik team

[Michel]

Hi !

Your second example is really different but it gave me a hint about grouping and I was able to map everything on the XAML side.

Now I get a single line and a single Legend entry for each MaterialName...  Thanks !

<telerik:RadChart ItemsSource="{Binding ForecastValueList}">
    <telerik:RadChart.DefaultView >
        <telerik:ChartDefaultView >
            <telerik:ChartDefaultView.ChartLegend>
                <telerik:ChartLegend x:Name="legend" Header="Materials"/>
            </telerik:ChartDefaultView.ChartLegend>
            <telerik:ChartDefaultView.ChartArea>
                <telerik:ChartArea LegendName="legend" EnableAnimations="False">
                    <telerik:ChartArea.AxisY>
                        <telerik:AxisY Title="Quantity" DefaultLabelFormat="#.0" />
                    </telerik:ChartArea.AxisY>
                    <telerik:ChartArea.AxisX>
                        <telerik:AxisX Title="Periods" DefaultLabelFormat="MMM-dd"/>
                    </telerik:ChartArea.AxisX>
                </telerik:ChartArea>
            </telerik:ChartDefaultView.ChartArea>
        </telerik:ChartDefaultView>
    </telerik:RadChart.DefaultView>
    <telerik:RadChart.SeriesMappings>
        <telerik:SeriesMapping>
            <telerik:SeriesMapping.SeriesDefinition>
                <telerik:LineSeriesDefinition LegendDisplayMode="SeriesLabel"/>
            </telerik:SeriesMapping.SeriesDefinition>
            <telerik:SeriesMapping.GroupingSettings>
                <telerik:GroupingSettings>
                    <telerik:GroupingSettings.GroupDescriptors>
                        <telerik:ChartGroupDescriptor Member="MaterialName" />
                    </telerik:GroupingSettings.GroupDescriptors>
                </telerik:GroupingSettings>
            </telerik:SeriesMapping.GroupingSettings>
            <telerik:ItemMapping DataPointMember="LegendLabel" FieldName="MaterialName"/>
            <telerik:ItemMapping DataPointMember="XValue" FieldName="Period" />
            <telerik:ItemMapping DataPointMember="YValue" FieldName="Quantity" />
        </telerik:SeriesMapping>
    </telerik:RadChart.SeriesMappings>
</telerik:RadChart>