ChartControl.CustomDrawCrosshair Event

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

Assembly : DevExpress.Xpf.Charts.v25.2.dll

NuGet Package : DevExpress.Wpf.Charts

Declaration

C#
VB.NET

csharp

public event CustomDrawCrosshairEventHandler CustomDrawCrosshair

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 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:

View Example

MainWindow.xaml

xaml

<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>

MainWindow.xaml.cs
MainWindow.xaml.vb

csharp

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;
            }
        }
    }
}

Imports DevExpress.Xpf.Charts
Imports System.Windows
Imports System.Windows.Media

Namespace CrosshairCustomDraw

    Public Partial Class MainWindow
        Inherits Window

        Private handleCustomDraw As Boolean

        Public Sub New()
            Me.InitializeComponent()
        End Sub

        Private Sub Button_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
            handleCustomDraw = True
            AddHandler Me.chartControl1.CustomDrawCrosshair, AddressOf Me.chartControl1_CustomDrawCrosshair
        End Sub

        Private Sub chartControl1_CustomDrawCrosshair(ByVal sender As Object, ByVal e As CustomDrawCrosshairEventArgs)
            If Not handleCustomDraw Then 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. 
            For Each axisLabelElement As CrosshairAxisLabelElement In e.CrosshairAxisLabelElements
                axisLabelElement.Background = Brushes.Blue
            Next

            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.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 Then
                    element.LabelElement.Foreground = Brushes.Green
                    element.LabelElement.FontSize = 14
                End If
            Next

            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.Foreground = Brushes.Red
                groupHeaderElement.FontSize = 15
            Next
        End Sub
    End Class
End Namespace

The following code snippet (auto-collected from DevExpress Examples) contains a reference 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.

XAML
C#
VB.NET

wpf-charts-custom-draw-crosshair-cursor/CS/CrosshairCustomDraw/MainWindow.xaml#L9

xml

<dxc:ChartControl Name="chartControl1" Height="340"
                  CustomDrawCrosshair="chartControl1_CustomDrawCrosshair">
    <dxc:ChartControl.CrosshairOptions>

wpf-charts-custom-draw-crosshair-cursor/CS/CrosshairCustomDraw/MainWindow.xaml.cs#L13

csharp

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

wpf-charts-custom-draw-crosshair-cursor/VB/CrosshairCustomDraw/MainWindow.xaml.vb#L18

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

ChartControl.CustomDrawCrosshair Event

ChartControl.CustomDrawCrosshair Event

Declaration

Event Data

Remarks

Example

Related GitHub Examples