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CrosshairElement Class

Represents crosshair elements (e.g., crosshair value lines, crosshair value labels, crosshair labels) that can be used to custom draw a crosshair cursor.

Namespace: DevExpress.Xpf.Charts

Assembly: DevExpress.Xpf.Charts.v22.1.dll

Declaration

[NonCategorized]
public class CrosshairElement :
    CrosshairElementBase

Remarks

Use the CustomDrawCrosshairEventArgs.CrosshairElements property to get access to the CrosshairElement object.

To learn more on crosshair cursors, see Tooltip and Crosshair Cursor.

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;
            }
        }
    }
}

Inheritance

See Also