Skip to main content

How to: Custom Draw a Crosshair Cursor

  • 4 minutes to read

This example demonstrates how to use the ChartControl.CustomDrawCrosshair event to modify the legend markers of bar series.

View Example

To access crosshair element groups, use the CustomDrawCrosshairEventArgs.CrosshairElementGroups property. Elements are separated into several groups when crosshair labels are displayed for each pane.

Use the following properties to access crosshair elements and customize them:

Gets the settings of crosshair group header elements to customize their appearance.
Gets the settings of crosshair elements (crosshair value lines, crosshair value labels, crosshair labels) to customize their appearance.
Returns the Crosshair Cursor‘s label element to change its settings when using the ChartControl.CustomDrawCrosshair event to modify the Crosshair’s appearance.
Returns the Crosshair Cursor‘s axis label element to change its settings when using the ChartControl.CustomDrawCrosshair event to modify the Crosshair’s appearance.
Specifies the marker image of a crosshair cursor label when implementing custom draw in the crosshair cursor.
using CustomDrawCrosshairSample.Model;
using DevExpress.Drawing;
using DevExpress.XtraCharts;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Linq;

namespace CustomDrawCrosshairSample {
    public partial class Form1 : DevExpress.XtraEditors.XtraForm {
        Dictionary<string, DXImage> photoCache = new Dictionary<string, DXImage>();
        Dictionary<string, DXBitmap> bitmapCache = new Dictionary<string, DXBitmap>();
        #region #Constants
        const int borderSize = 2;
        const int scaledPhotoWidth = 32;
        const int scaledPhotoHeight = 34;
        // Width and height of scaled photo with border.
        const int totalWidth = 36;
        const int totalHeight = 38;

        // Rects required to create a custom legend series marker.
        static readonly Rectangle photoRect = new Rectangle(
                borderSize, borderSize,
                scaledPhotoWidth, scaledPhotoHeight);
        static readonly Rectangle totalRect = new Rectangle(
                0, 0,
                totalWidth, totalHeight);

        public Form1() {

        private void Form1_Load(object sender, EventArgs e) {
            using (var context = new NwindDbContext()) {
                chart.DataSource = context.Orders.ToList();

            chart.SeriesDataMember = "Employee.FullName";
            chart.SeriesTemplate.ArgumentDataMember = "OrderDate";

            XYDiagram diagram = chart.Diagram as XYDiagram;
            if (diagram != null) {
                diagram.AxisX.DateTimeScaleOptions.AggregateFunction = AggregateFunction.Sum;
                diagram.AxisX.DateTimeScaleOptions.MeasureUnit = DateTimeMeasureUnit.Year;

            chart.CustomDrawCrosshair += OnCustomDrawCrosshair;

        void InitPhotoCache(IEnumerable<Employee> employees) {
            foreach (var employee in employees) {
                using (MemoryStream stream = new MemoryStream(employee.Photo)) {
                    if (!photoCache.ContainsKey(employee.FullName))
                        photoCache.Add(employee.FullName, DXImage.FromStream(stream));

        #region #CustomDrawCrosshairHandler
        private void OnCustomDrawCrosshair(object sender, CustomDrawCrosshairEventArgs e) {
            foreach (CrosshairElementGroup group in e.CrosshairElementGroups) {
                if (group.CrosshairElements[0] != null)
                    group.HeaderElement.Text = String.Format("Sales in {0:yyyy}", group.CrosshairElements[0].SeriesPoint.DateTimeArgument);
                foreach (CrosshairElement element in group.CrosshairElements) {
                    DXBitmap image;
                    if (!bitmapCache.TryGetValue(element.Series.Name, out image)) {
                        image = new DXBitmap(totalWidth, totalHeight);
                        using (DXGraphics graphics = DXGraphics.FromImage(image)) {
                            using (DXSolidBrush brush = new DXSolidBrush(element.LabelElement.MarkerColor)) {
                                graphics.FillRectangle(brush, totalRect);
                            DXImage photo;
                            if (photoCache.TryGetValue(element.Series.Name, out photo))
                                graphics.DrawImage(photo, photoRect);
                        bitmapCache.Add(element.Series.Name, image);
                    element.LabelElement.DXMarkerImage = image;
                    element.LabelElement.MarkerSize = new Size(totalWidth, totalHeight);