ChartControl.CustomDrawCrosshair Event
Occurs before crosshair items are drawn when the chart’s contents are being drawn.
Namespace: DevExpress.XtraCharts
Assembly: DevExpress.XtraCharts.v19.1.UI.dll
Declaration
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
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);
}
}
}
}
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.