[Solved] How to handle 0% of data points in label definition in DoughnutSeries

[Zubair]

Hi i used DoughnutSeries chart in my windows store app . problem is that when legend is 0 percent then label show 0%. i want to remove label definition for specific 0 percent data points. for better understanding i attach picture of chart. i want to handle 0 percent that is on right side of chart 
thanks

[Ivaylo Gergov]

Hi,

In your scenario I can suggest that you change the ChartSeriesLabelDefinition.Template and use a ValueConvertor to skip a label which is 0%. Here's an example:

<telerikChart:DoughnutSeries.LabelDefinitions>
    <telerikChart:ChartSeriesLabelDefinition>
       <telerikChart:ChartSeriesLabelDefinition.Template>
            <DataTemplate>
                <TextBlock Text="{Binding Converter={StaticResource converter}}"/>
            </DataTemplate>
       </telerikChart:ChartSeriesLabelDefinition.Template>
    </telerikChart:ChartSeriesLabelDefinition>
</telerikChart:DoughnutSeries.LabelDefinitions>

<Page.Resources>
    <local:Converter x:Key="converter"/>
</Page.Resources>

Where the Converter class looks like this: 

public class Converter : IValueConverter
 {
     public object Convert(object value, Type targetType, object parameter, string language)
     {
         var dataPoint = value as DoughnutDataPoint;
         var percent = dataPoint.Percent;

         if (percent == 0)
         {
             return "";
         }
         else
         {
             return String.Format("{0}%",percent);
         }
     }

     public object ConvertBack(object value, Type targetType, object parameter, string language)
     {
         throw new NotImplementedException();
     }
 }

I hope this helps.

Regards,
Ivaylo Gergov
Telerik

[Zubair]

thanks for u r reply . Overlapping of labels hurt me more. have u any solution for this problem ? Check attach file thnks.

[Ivaylo Gergov]

Hi,

Currently the RadChart does not support Smart Labels i.e. to automatically align labels so that each labeled value stands out clearly. I have logged this as a feature request in our Ideas and Feedback portal where you can vote for it and raise its priority.

Thank you for your valuable feedback.

Regards,
Ivaylo Gergov
Telerik