CrosshairElementGroup.HeaderElement Property

Gets the settings of crosshair group header elements to customize their appearance.

Namespace: DevExpress.XtraCharts

Assembly: DevExpress.XtraCharts.v24.1.dll

NuGet Package: DevExpress.Charts

Declaration

C#

public CrosshairGroupHeaderElement HeaderElement { get; }

VB.NET

Public ReadOnly Property HeaderElement As CrosshairGroupHeaderElement

Property Value

Type	Description
CrosshairGroupHeaderElement	An object implementing the System.Collections.IEnumerable interface that represents the CrosshairGroupHeaderElement collection.

Remarks

Use the HeaderElement property to get access to the appearance settings of the crosshair group header elements when implementing the ChartControl.CustomDrawCrosshair event.

To learn more about a crosshair cursor, see Tooltip and Crosshair Cursor.

Example

This example shows how to use the ChartControl.CustomDrawCrosshair event to create a custom appearance for the crosshair cursor. This event is invoked when you select the Custom Draw Crosshair Cursor check box.

If you wish to display crosshair axis lines and labels on a chart before custom drawing the crosshair cursor, set the CrosshairOptions.ShowArgumentLine, CrosshairOptions.ShowArgumentLabels, CrosshairOptions.ShowValueLabels and CrosshairOptions.ShowValueLine properties to true.

Note that the crosshair cursor customization is available for the CrosshairOptions.SnapMode property set to NearestArgument.

View Example

Form1.cs

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

namespace CustomDrawCrosshairCursor {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }
        private void OnCheckEditCheckedChanged(object sender, EventArgs e) {
            if (checkEdit1.Checked)
                chartControl1.CustomDrawCrosshair += OnChartControlCustomDrawCrosshair;
            else 
                chartControl1.CustomDrawCrosshair -= OnChartControlCustomDrawCrosshair;               
        }

        private void OnChartControlCustomDrawCrosshair(object sender, CustomDrawCrosshairEventArgs e) {
            // Specify the crosshair argument line color, dash style and thickness.
            e.CrosshairLineElement.Color = Color.Green;
            e.CrosshairLineElement.LineStyle.DashStyle = DashStyle.DashDot;
            e.CrosshairLineElement.LineStyle.Thickness = 3;

            // Specify the back color for the crosshair argument axis label. 
            foreach (CrosshairAxisLabelElement axisLabelElement in e.CrosshairAxisLabelElements)
                axisLabelElement.BackColor = Color.Blue;

            foreach (CrosshairElementGroup group in e.CrosshairElementGroups) {
                CrosshairGroupHeaderElement groupHeaderElement = group.HeaderElement;

                // Specify the text, text color and font for the crosshair group header element. 
                groupHeaderElement.Text = "Custom draw";
                groupHeaderElement.TextColor = Color.Green;
                groupHeaderElement.DXFont = new DXFont("SegoeUI", 12, DXFontStyle.Bold);

                // Obtain the first series.
                CrosshairElement element = group.CrosshairElements[0];

                // Specify the color, dash style and thickness for the crosshair value lines. 
                element.LineElement.Color = Color.DarkViolet;
                element.LineElement.LineStyle.DashStyle = DashStyle.Dash;
                element.LineElement.LineStyle.Thickness = 2;

                // Specify the text color and back color for the crosshair value labels.
                element.AxisLabelElement.TextColor = Color.Red;
                element.AxisLabelElement.BackColor = Color.Yellow;

                // Format the text shown for the series in the crosshair cursor label. Specify the text color and marker size. 
                element.LabelElement.TextColor = Color.Red;
                element.LabelElement.MarkerSize = new Size(15, 15);
                element.LabelElement.Text = string.Format("{0}: A={1}; V={2}", element.Series.Name, element.SeriesPoint.Argument, element.SeriesPoint.Values[0]);
            }
        }
    }
}

Form1.vb

Imports System
Imports System.Drawing
Imports System.Windows.Forms
Imports DevExpress.Drawing
Imports DevExpress.XtraCharts

Namespace CustomDrawCrosshairCursor

    Public Partial Class Form1
        Inherits Form

        Public Sub New()
            InitializeComponent()
        End Sub

        Private Sub OnCheckEditCheckedChanged(ByVal sender As Object, ByVal e As EventArgs)
            If checkEdit1.Checked Then
                AddHandler chartControl1.CustomDrawCrosshair, AddressOf OnChartControlCustomDrawCrosshair
            Else
                RemoveHandler chartControl1.CustomDrawCrosshair, AddressOf OnChartControlCustomDrawCrosshair
            End If
        End Sub

        Private Sub OnChartControlCustomDrawCrosshair(ByVal sender As Object, ByVal e As CustomDrawCrosshairEventArgs)
            ' Specify the crosshair argument line color, dash style and thickness.
            e.CrosshairLineElement.Color = Color.Green
            e.CrosshairLineElement.LineStyle.DashStyle = DashStyle.DashDot
            e.CrosshairLineElement.LineStyle.Thickness = 3
            ' Specify the back color for the crosshair argument axis label. 
            For Each axisLabelElement As CrosshairAxisLabelElement In e.CrosshairAxisLabelElements
                axisLabelElement.BackColor = Color.Blue
            Next

            For Each group As CrosshairElementGroup In e.CrosshairElementGroups
                Dim groupHeaderElement As CrosshairGroupHeaderElement = group.HeaderElement
                ' Specify the text, text color and font for the crosshair group header element. 
                groupHeaderElement.Text = "Custom draw"
                groupHeaderElement.TextColor = Color.Green
                groupHeaderElement.DXFont = New DXFont("SegoeUI", 12, DXFontStyle.Bold)
                ' Obtain the first series.
                Dim element As CrosshairElement = group.CrosshairElements(0)
                ' Specify the color, dash style and thickness for the crosshair value lines. 
                element.LineElement.Color = Color.DarkViolet
                element.LineElement.LineStyle.DashStyle = DashStyle.Dash
                element.LineElement.LineStyle.Thickness = 2
                ' Specify the text color and back color for the crosshair value labels.
                element.AxisLabelElement.TextColor = Color.Red
                element.AxisLabelElement.BackColor = Color.Yellow
                ' Format the text shown for the series in the crosshair cursor label. Specify the text color and marker size. 
                element.LabelElement.TextColor = Color.Red
                element.LabelElement.MarkerSize = New Size(15, 15)
                element.LabelElement.Text = String.Format("{0}: A={1}; V={2}", element.Series.Name, element.SeriesPoint.Argument, element.SeriesPoint.Values(0))
            Next
        End Sub
    End Class
End Namespace

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the HeaderElement property.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

winforms-chart-draw-a-crosshair-cursor/CS/CustomDrawCrosshairCursor/Form1.cs#L30

foreach (CrosshairElementGroup group in e.CrosshairElementGroups) {
    CrosshairGroupHeaderElement groupHeaderElement = group.HeaderElement;

VB.NET

winforms-chart-draw-a-crosshair-cursor/VB/CustomDrawCrosshairCursor/Form1.vb#L35

For Each group As CrosshairElementGroup In e.CrosshairElementGroups
    Dim groupHeaderElement As CrosshairGroupHeaderElement = group.HeaderElement
    ' Specify the text, text color and font for the crosshair group header element.