ChartControl.CustomDrawCrosshair Event

Occurs before crosshair items are drawn when the chart’s contents are being drawn.

Namespace: DevExpress.XtraCharts

Assembly: DevExpress.XtraCharts.v23.2.UI.dll

NuGet Package: DevExpress.Win.Charts

Declaration

C#

public event CustomDrawCrosshairEventHandler CustomDrawCrosshair

VB.NET

Public Event CustomDrawCrosshair As CustomDrawCrosshairEventHandler

Event Data

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

Property	Description
CrosshairAxisLabelElements	Gets the settings of crosshair axis label elements to customize their appearance.
CrosshairElementGroups	Provides access to the settings of crosshair elements and crosshair group header elements to customize their appearance.
CrosshairElements	Obsolete. Gets the settings of crosshair elements (crosshair value lines, crosshair value labels, crosshair labels) to customize their appearance.
CrosshairGroupHeaderElements	Obsolete. Gets the settings of crosshair group header elements to customize their appearance.
CrosshairLegendElements	Returns crosshair legend elements to customize their appearance.
CrosshairLineElement	Gets the settings of a crosshair line element to customize its appearance (color, line style).
IndicatorLegendElements	Returns all indicator elements that the Crosshair Cursor shows in a legend.

Remarks

Use the CustomDrawCrosshair event to create a custom appearance for crosshair items.

Review the following help topic for information about scenarios you can implement when you handle CustomDrawCrosshair: Customize the Crosshair Cursor at Runtime.

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 want to display crosshair axis lines and labels on a chart before 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 when it is 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 snippets (auto-collected from DevExpress Examples) contain references to the CustomDrawCrosshair event.

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#L14

if (checkEdit1.Checked)
    chartControl1.CustomDrawCrosshair += OnChartControlCustomDrawCrosshair;
else

winforms-chart-draw-a-custom-series-marker-in-the-crosshair/CS/CustomDrawCrosshairSample/Form1.cs#L51

    chart.CustomDrawCrosshair += OnCustomDrawCrosshair;
}

VB.NET

winforms-chart-draw-a-crosshair-cursor/VB/CustomDrawCrosshairCursor/Form1.vb#L18

If checkEdit1.Checked Then
    AddHandler chartControl1.CustomDrawCrosshair, AddressOf OnChartControlCustomDrawCrosshair
Else

winforms-chart-draw-a-custom-series-marker-in-the-crosshair/VB/CustomDrawCrosshairSample/Form1.vb#L56

    AddHandler chart.CustomDrawCrosshair, AddressOf OnCustomDrawCrosshair
End Sub