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CustomDrawCrosshairEventArgs.CrosshairElementGroups Property

Provides access to the settings of crosshair elements and crosshair group header elements to customize their appearance.

Namespace: DevExpress.Xpf.Charts

Assembly: DevExpress.Xpf.Charts.v24.1.dll

NuGet Package: DevExpress.Wpf.Charts

Declaration

public List<CrosshairElementGroup> CrosshairElementGroups { get; }

Property Value

Type Description
List<CrosshairElementGroup>

An object implementing the System.Collections.IList interface that represents the CrosshairElementGroup collection.

Remarks

Use the CrosshairElementGroups property to get access to the settings of a crosshair element group when handling the ChartControl.CustomDrawCrosshair event. After that, you can access the appearance settings of crosshair elements using the CrosshairElementGroup.CrosshairElements property and crosshair group header elements using the CrosshairElementGroup.HeaderElement property.

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

<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;
            }
        }
    }
}

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

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.

See Also