ChartBase.SelectionChanged Event

Occurs when the chart selection is changed.

Namespace: DevExpress.WinUI.Charts

Assembly: DevExpress.WinUI.Charts.v23.2.dll

NuGet Package: DevExpress.WinUI

Declaration

C#

public event ChartElementSelectionChangedEventHandler SelectionChanged

VB.NET

Public Event SelectionChanged As ChartElementSelectionChangedEventHandler

Event Data

The SelectionChanged event's data class is ChartElementSelectionChangedEventArgs. The following properties provide information specific to this event:

Property	Description
ChangedElement	Returns the chart element that is currently selected or deselected.
IsSelected	Returns the selection state of the chart element that is currently selected or deselected.
Selection	Returns a list of items that are selected in a chart. Inherited from ElementSelectionChangedEventArgs.

Remarks

The ChartBase.SelectionChanged event occurs when a user selects or deselects series points. Use the e.Selection property to obtain selected items. The following example calculates the total area of selected countries:

C#

private void chartOfCountriesArea_SelectionChanged(object sender, ChartElementSelectionChangedEventArgs e) {
    double totalArea = 0;
    foreach (CountryStatisticInfo point in e.Selection) {
        totalArea += point.AreaMSqrKilometers;
    }
    selectedItemsText.Text = String.Format("Total area of ​​selected countries: {0}", totalArea);
}

VB.NET

Private Sub chartOfCountriesArea_SelectionChanged(ByVal sender As Object, ByVal e As ChartElementSelectionChangedEventArgs)
    Dim totalArea As Double = 0
    For Each point As CountryStatisticInfo In e.Selection
        totalArea += point.AreaMSqrKilometers
    Next
    selectedItemsText.Text = String.Format("Total area of ​​selected countries: {0}", totalArea)
End Sub

Use the e.ChangedElement property to get the series point whose selection state is changed. The e.IsSelected property returns this selection state. The following code calls a custom UpdateStatistics method for the last selected series point:

C#

private void chartOfCountriesArea_SelectionChanged(object sender, ChartElementSelectionChangedEventArgs e) {
    selectedItemsText.Text = String.Format("Total area of ​​selected countries: {0}", totalArea);
    if (e.IsSelected) {
        UpdateStatistics((CountryStatisticInfo)e.ChangedElement);
    }
}

VB.NET

Private Sub chartOfCountriesArea_SelectionChanged(ByVal sender As Object, ByVal e As ChartElementSelectionChangedEventArgs)
    selectedItemsText.Text = String.Format("Total area of ​​selected countries: {0}", totalArea)
    If e.IsSelected Then
        UpdateStatistics(CType(e.ChangedElement, CountryStatisticInfo))
    End If
End Sub