How to change the series selection when clicking the legend items in WPF Chart?

Description

This article demonstrates how to change the the Interior of a Series when its LegendItem is clicked. By handling the MouseDown event of the ChartLegend and you can get the Series of corresponding LegendItem from the MouseButtonEventArgs.

Solution

To achieve this functionality, follow the steps below:

Step 1: Define the ChartLegend with MouseDown Event.

XAML:

 
   <chart:SfChart.Legend>
         <chart:ChartLegend MouseDown="ChartLegend_MouseDown"/>
   </chart:SfChart.Legend>
 

Step 2: Implement the MouseDown Event Handler.

In the code-behind, implement the ChartLegend_MouseDown event handler to toggle the Interior property of the clicked series.

C#:

  
    public partial class MainWindow : Window
    {
        private ChartSeriesBase prevSeries;
        private void ChartLegend_MouseDown(object sender, MouseButtonEventArgs e)
        {       …
                if (series != null)
                {
                    if (prevSeries != series && prevSeries != null)
                        prevSeries.Interior = null;
 
                    if (series.Interior == null)
                        series.Interior = new SolidColorBrush(Colors.Red);
                    else
                        series.Interior = null;
 
                    prevSeries = series;
                }
        }
    }
 

In this example, clicking a legend item toggles the interior color of the corresponding series indicating selection. 

Conclusion

I hope you enjoyed learning about how to change the series selection when clicking the legend items in WPF Chart.

You can refer to our WPF Chart feature tour page to know about its other groundbreaking feature representations and documentation, and how to quickly get started for configuration specifications. You can also explore our WPF Chart example to understand how to create and manipulate data.

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