ChartControl.CustomDrawCrosshair Event
Occurs before crosshair items are drawn when the chart’s contents are being drawn.
Namespace: DevExpress.Xpf.Charts
Assembly: DevExpress.Xpf.Charts.v23.2.dll
NuGet Package: DevExpress.Wpf.Charts
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 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). |
| Handled | Gets or sets a value that indicates the present state of the event handling for a routed event as it travels the route. Inherited from RoutedEventArgs. |
| IndicatorLegendElements | Returns all indicator elements that the Crosshair Cursor shows in a legend. |
| OriginalSource | Gets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class. Inherited from RoutedEventArgs. |
| RoutedEvent | Gets or sets the RoutedEvent associated with this RoutedEventArgs instance. Inherited from RoutedEventArgs. |
| Source | Gets or sets a reference to the object that raised the event. Inherited from RoutedEventArgs. |
The event data class exposes the following methods:
| Method | Description |
|---|---|
| InvokeEventHandler(Delegate, Object) | When overridden in a derived class, provides a way to invoke event handlers in a type-specific way, which can increase efficiency over the base implementation. Inherited from RoutedEventArgs. |
| OnSetSource(Object) | When overridden in a derived class, provides a notification callback entry point whenever the value of the Source property of an instance changes. Inherited from RoutedEventArgs. |
Remarks
Use the CustomDrawCrosshair event to create a custom appearance for crosshair items.
Example
This example shows how to use the ChartControl.CustomDrawCrosshair event to customize the crosshair cursor. For example, you can use this event to paint crosshair label items depending on the highlighted point value. In this example, the ChartControl.CustomDrawCrosshair event is invoked when you click the Custom Draw Crosshair Cursor button on the form.
Enable the following properties before the crosshair is customized to display crosshair axis lines and labels:
- CrosshairOptions.ShowArgumentLabels
- CrosshairOptions.ShowArgumentLine
- CrosshairOptions.ShowValueLabels
- CrosshairOptions.ShowValueLine
<Window x:Class="CrosshairCustomDraw.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:dxc="http://schemas.devexpress.com/winfx/2008/xaml/charts"
Title="MainWindow" Height="414" Width="525">
<Grid>
<StackPanel>
<dxc:ChartControl Name="chartControl1" Height="340"
CustomDrawCrosshair="chartControl1_CustomDrawCrosshair">
<dxc:ChartControl.CrosshairOptions>
<dxc:CrosshairOptions ShowArgumentLabels="True"
ShowArgumentLine="True"
ShowValueLabels="True"
ShowValueLine="True"/>
</dxc:ChartControl.CrosshairOptions>
<dxc:XYDiagram2D>
<dxc:XYDiagram2D.AxisX>
<dxc:AxisX2D>
<dxc:AxisX2D.CrosshairAxisLabelOptions>
<dxc:CrosshairAxisLabelOptions Pattern="{}{V:f1}"/>
</dxc:AxisX2D.CrosshairAxisLabelOptions>
</dxc:AxisX2D>
</dxc:XYDiagram2D.AxisX>
<dxc:LineSeries2D DisplayName="Series1">
<dxc:SeriesPoint Argument="1" Value="50"/>
<dxc:SeriesPoint Argument="2" Value="44"/>
<dxc:SeriesPoint Argument="3" Value="55"/>
<dxc:SeriesPoint Argument="4" Value="77"/>
</dxc:LineSeries2D>
<dxc:LineSeries2D DisplayName="Series2">
<dxc:SeriesPoint Argument="1" Value="22"/>
<dxc:SeriesPoint Argument="2" Value="11"/>
<dxc:SeriesPoint Argument="3" Value="9"/>
<dxc:SeriesPoint Argument="4" Value="8"/>
</dxc:LineSeries2D>
</dxc:XYDiagram2D>
</dxc:ChartControl>
<Button Height="35" Content="Custom Draw Crosshair Cursor" Click="Button_Click"></Button>
</StackPanel>
</Grid>
</Window>
using DevExpress.Xpf.Charts;
using System.Windows;
using System.Windows.Media;
namespace CrosshairCustomDraw {
public partial class MainWindow : Window {
bool handleCustomDraw;
public MainWindow() {
InitializeComponent();
}
private void Button_Click(object sender, RoutedEventArgs 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.Brush = Brushes.Aqua;
e.CrosshairLineElement.LineStyle.DashStyle = DashStyles.DashDot;
e.CrosshairLineElement.LineStyle.Thickness = 3;
// Specify the back color for crosshair argument label.
foreach (CrosshairAxisLabelElement axisLabelElement in e.CrosshairAxisLabelElements)
axisLabelElement.Background = Brushes.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.Brush = Brushes.DarkViolet;
element.LineElement.LineStyle.DashStyle = DashStyles.Dash;
element.LineElement.LineStyle.Thickness = 2;
// Specify the font size and background for the crosshair value labels.
element.AxisLabelElement.FontSize = 14;
element.AxisLabelElement.Background = Brushes.Red;
// Specify the foreground and font size for the crosshair cursor label that shows series.
if (element.SeriesPoint.Value > 50) {
element.LabelElement.Foreground = Brushes.Green;
element.LabelElement.FontSize = 14;
}
}
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.Foreground = Brushes.Red;
groupHeaderElement.FontSize = 15;
}
}
}
}
Related GitHub Examples
The following code snippet (auto-collected from DevExpress Examples) contains a reference to the CustomDrawCrosshair event.
Note
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