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BaseCrosshairLabelElement Class

The base class for classes that provide functionality for crosshair label elements.

Namespace: DevExpress.XtraCharts

Assembly: DevExpress.XtraCharts.v18.2.dll

Declaration

[RuntimeObject]
public abstract class BaseCrosshairLabelElement
<RuntimeObject>
Public MustInherit Class BaseCrosshairLabelElement

Remarks

The BaseCrosshairLabelElement class serves as a base for classes that provide the crosshair label element functionality of the crosshair cursor.

Use the properties of the BaseCrosshairLabelElement when custom drawing the crosshair cursor using the ChartControl.CustomDrawCrosshair event handler.

For more information, refer to Tooltip and Crosshair Cursor.

Examples

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.


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);
            }
        }
    }
}
See Also