ChartControl.CustomDrawCrosshair Event

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

Namespace: DevExpress.XtraCharts

Assembly: DevExpress.XtraCharts.v18.2.UI.dll

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 of crosshair items.

Example

This example shows how to provide a custom appearance for the crosshair cursor using the ChartControl.CustomDrawCrosshair event. This event is invoked when you click the Custom Draw Crosshair Cursor button on the form.

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 customization of the crosshair cursor is provided for the CrosshairOptions.SnapMode property set to NearestArgument.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-custom-draw-a-crosshair-cursor-e4307

Form1.cs

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

namespace CustomDrawCrosshairCursor {
    public partial class Form1 : Form {
        bool handleCustomDraw;
        public Form1() {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e) {
            handleCustomDraw = true;
            chartControl1.CustomDrawCrosshair += chartControl1_CustomDrawCrosshair;
        }

        private void chartControl1_CustomDrawCrosshair(object sender, CustomDrawCrosshairEventArgs e) {
            if (!handleCustomDraw) return;

            // 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 crosshair argument label. 
            foreach (CrosshairAxisLabelElement axisLabelElement in e.CrosshairAxisLabelElements)
                axisLabelElement.BackColor = Color.Blue;

            foreach (CrosshairElementGroup group in e.CrosshairElementGroups) {
                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;

                // Specify the text color and marker size for the crosshair  cursor label that shows series. 
                element.LabelElement.TextColor = Color.Red;
                element.LabelElement.MarkerSize = new Size(15, 15);
            }

            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.Font = new Font(this.Font, FontStyle.Bold);
            }
        }
    }
}

Form1.vb

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

Namespace CustomDrawCrosshairCursor
    Partial Public Class Form1
        Inherits Form

        Private handleCustomDraw As Boolean
        Public Sub New()
            InitializeComponent()
        End Sub

        Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles button1.Click
            handleCustomDraw = True
            AddHandler chartControl1.CustomDrawCrosshair, AddressOf chartControl1_CustomDrawCrosshair
        End Sub

        Private Sub chartControl1_CustomDrawCrosshair(ByVal sender As Object, ByVal e As CustomDrawCrosshairEventArgs) Handles chartControl1.CustomDrawCrosshair
            If Not handleCustomDraw Then
                Return
            End If

            ' 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 crosshair argument label. 
            For Each axisLabelElement As CrosshairAxisLabelElement In e.CrosshairAxisLabelElements
                axisLabelElement.BackColor = Color.Blue
            Next axisLabelElement

            For Each group As CrosshairElementGroup In e.CrosshairElementGroups
                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

                ' Specify the text color and marker size for the crosshair  cursor label that shows series. 
                element.LabelElement.TextColor = Color.Red
                element.LabelElement.MarkerSize = New Size(15, 15)
            Next group

            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.Font = New Font(Me.Font, FontStyle.Bold)
            Next group
        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#

how-to-custom-draw-a-crosshair-cursor-e4307/CS/CustomDrawCrosshairCursor/Form1.cs#L16

    handleCustomDraw = true;
    chartControl1.CustomDrawCrosshair += chartControl1_CustomDrawCrosshair;
}

how-to-draw-a-custom-series-marker-in-the-crosshair-t333191/CS/CustomDrawCrosshairSample/Form1.cs#L51

    chart.CustomDrawCrosshair += OnCustomDrawCrosshair;
}

VB.NET

how-to-custom-draw-a-crosshair-cursor-e4307/VB/CustomDrawCrosshairCursor/Form1.vb#L17

    handleCustomDraw = True
    AddHandler chartControl1.CustomDrawCrosshair, AddressOf chartControl1_CustomDrawCrosshair
End Sub

how-to-draw-a-custom-series-marker-in-the-crosshair-t333191/VB/CustomDrawCrosshairSample/Form1.vb#L49

    AddHandler chart.CustomDrawCrosshair, AddressOf OnCustomDrawCrosshair
End Sub