ChartControl.SelectionMode Property

Gets or sets a value which specifies how the chart elements are selected.

Namespace: DevExpress.XtraCharts

Assembly: DevExpress.XtraCharts.v21.1.UI.dll

Declaration

public ElementSelectionMode SelectionMode { get; set; }

Property Value

Type Description
ElementSelectionMode

An ElementSelectionMode enumeration member specifying the chart’s selection behavior.

Available values:

Name Description
None

The selection of a chart element is disabled.

Single

Selects the only chart element.

ElementSelectionMode.Single

Multiple

Selects multiple chart elements.

ElementSelectionMode.Multiple

Extended

Selects multiple chart elements (while the SHIFT key is pressed) and selects/deselects chart elements (while the Ctrl key is pressed).

ElementSelectionMode.Extended

Remarks

Note, that the chart selection is not cleared when this property is set to None. To clear the selection, call the ChartControl.ClearSelection method.

Example

This example shows how to obtain currently selected series points and show them in another chart. To do this, the ChartControl.SelectedItemsChanged event should be used.

In this example, you can choose the selection behavior (Single, Multiple or Extended) from the Selection Mode combo box. When any country is selected in the pie chart, you can see the population dynamics for each country in the bar chart. To cancel pie segment selection, choose None in the Selection Mode combo box.

In addition, this example demonstrates how to colorize each bar series point in the pie specific color using the ChartControl.CustomDrawSeriesPoint event.

View Example

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;
using DevExpress.XtraCharts;

namespace ChartSelection {

    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }

        PaletteEntry[] paletteEntries;

        private void Form1_Load(object sender, EventArgs e) {

            // Specify selection mode for the Pie chart.
            this.cbSelectionMode.Properties.Items.AddRange(Enum.GetValues(typeof(ElementSelectionMode)));
            this.cbSelectionMode.SelectedIndex = 2;
            pieChart.SeriesSelectionMode = SeriesSelectionMode.Point;

            // Handle the SelectedItemsChanged event for the Pie chart.                
            pieChart.SelectedItemsChanged += pieChart_SelectedItemsChanged;

            // Handle the CustomDrawSeriesPoint event for the Bar chart. 
            barChart.CustomDrawSeriesPoint += barChart_CustomDrawSeriesPoint;

            // Get palette entries of the pie chart.
            paletteEntries = pieChart.GetPaletteEntries(pieChart.Series[0].Points.Count);
        }

        private void cbSelectionMode_SelectedIndexChanged(object sender, EventArgs e) {
            pieChart.SelectionMode = (ElementSelectionMode)this.cbSelectionMode.SelectedItem;
        }

        private void pieChart_SelectedItemsChanged(object sender, SelectedItemsChangedEventArgs e) {
            barChart.Series[0].Points.Clear();

            foreach (SeriesPoint piePoint in pieChart.SelectedItems) {
                SeriesPoint barPoint = new SeriesPoint(piePoint.Argument, piePoint.Values[0]);
                barPoint.Tag = pieChart.Series[0].Points.IndexOf(piePoint);
                barChart.Series[0].Points.Add(barPoint);
            }
        }

        private void barChart_CustomDrawSeriesPoint(object sender, CustomDrawSeriesPointEventArgs e) {
            BarDrawOptions barOptions = e.SeriesDrawOptions as BarDrawOptions;
            int colorIndex = (int)e.SeriesPoint.Tag;
            barOptions.Color = paletteEntries[colorIndex].Color;
        }
    }
}
See Also