Annotation Class

An additional note that can be anchored to a chart, pane, or series point.

Namespace: DevExpress.Xpf.Charts

Assembly: DevExpress.Xpf.Charts.v20.1.dll

NuGet Packages: DevExpress.WindowsDesktop.Wpf.Charts, DevExpress.Wpf.Charts

Declaration

C#

public class Annotation :
    ChartNotificationElement,
    IWeakEventListener,
    IHitTestableElement,
    IInteractiveElement,
    IScrollBarAnnotation

VB.NET

Public Class Annotation
    Inherits ChartNotificationElement
    Implements IWeakEventListener,
               IHitTestableElement,
               IInteractiveElement,
               IScrollBarAnnotation

Related API Members

The following members return Annotation objects:

• ChartHitInfoBase.Annotation

Remarks

For more information about annotations, refer to the following help topic: Annotations.

Examples

Add an Annotation in Markup

This example demonstrates how to anchor an annotation to a series point.

To do this, specify the SeriesPointAnchorPoint.SeriesPoint property.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-anchor-annotations-to-various-points-t378313.

MainWindow.xaml

<dxc:Annotation Content="Annotation #1">
    <dxc:Annotation.AnchorPoint>
        <dxc:SeriesPointAnchorPoint SeriesPoint="{Binding ElementName=seriesPoint}"/>
    </dxc:Annotation.AnchorPoint>
    <dxc:Annotation.ShapePosition>
        <dxc:RelativePosition Angle="60" 
                              ConnectorLength="50"/>
    </dxc:Annotation.ShapePosition>
</dxc:Annotation>

Add an Annotation in Code

The following example creates an annotation that is anchored to a pane.

XAML

<dxc:ChartControl x:Name="chartControl">
    <dxc:XYDiagram2D x:Name="diagram">
        <dxc:XYDiagram2D.SecondaryAxesX>
            <dxc:SecondaryAxisX2D x:Name="xAxis"/>
        </dxc:XYDiagram2D.SecondaryAxesX>
        <dxc:XYDiagram2D.SecondaryAxesY>
            <dxc:SecondaryAxisY2D x:Name="yAxis"/>
        </dxc:XYDiagram2D.SecondaryAxesY>
        <dxc:XYDiagram2D.Panes>
            <dxc:Pane x:Name="pane"/>
        </dxc:XYDiagram2D.Panes>
        <!--...-->
    </dxc:XYDiagram2D>
</dxc:ChartControl>

C#

using DevExpress.Xpf.Charts;
//...
private void Window_Loaded(object sender, RoutedEventArgs e) {
    Annotation annotation = new Annotation();
    annotation.Content = "Annotation";
    annotation.AnchorPoint = new PaneAnchorPoint {
        AxisXCoordinate = new AxisXCoordinate { AxisValue = new TimeSpan(0, 0, 5), Axis = xAxis },
        AxisYCoordinate = new AxisYCoordinate { AxisValue = 100, Axis = yAxis }, 
        Pane = pane
    };
    annotation.ShapePosition = new RelativePosition { Angle = 30, ConnectorLength = 60 };
    chartControl.Annotations.Add(annotation);
}

VB.NET

Imports DevExpress.Xpf.Charts
'...
Private Sub Window_Loaded(ByVal sender As Object, ByVal e As RoutedEventArgs)
    Dim annotation As Annotation = New Annotation()
    annotation.Content = "Annotation"
    annotation.AnchorPoint = New PaneAnchorPoint With {
        .AxisXCoordinate = New AxisXCoordinate With {
            .AxisValue = New TimeSpan(0, 0, 5),
            .Axis = xAxis
        },
        .AxisYCoordinate = New AxisYCoordinate With {
            .AxisValue = 100,
            .Axis = yAxis
        },
        pane
    }
    annotation.ShapePosition = New RelativePosition With {
        .Angle = 30,
        .ConnectorLength = 60
    }
    chartControl.Annotations.Add(annotation)
End Sub

If the chart is bound to data and you want to anchor an annotation to a series point, use the ChartControl.BoundDataChanged event to access the point collection. The following example creates an annotation for each point of a spline series.

XAML

<dxc:ChartControl x:Name="chartControl" 
                  BoundDataChanged="chartControl_BoundDataChanged">
    <dxc:XYDiagram2D x:Name="diagram">
        <dxc:SplineSeries2D>
            <!--...-->
        </dxc:SplineSeries2D>
    </dxc:XYDiagram2D>
</dxc:ChartControl>

C#

using DevExpress.Xpf.Charts;
//...
private void chartControl_BoundDataChanged(object sender, RoutedEventArgs e) {
    SplineSeries2D series = (SplineSeries2D)diagram.Series[0];
    if (series.Points.Count > 0) {
        for (int i = 0; i < series.Points.Count; i++) {
            chartControl.Annotations.BeginInit();
            Annotation annotation = new Annotation() { 
                Content = series.Points[i].Value.ToString() 
            };
            annotation.AnchorPoint = new SeriesPointAnchorPoint() { 
                SeriesPoint = series.Points[i] 
            };
            annotation.ShapePosition = new RelativePosition() { 
                Angle = 0, 
                ConnectorLength = 0 
            };
            chartControl.Annotations.Add(annotation);
            chartControl.Annotations.EndInit();
        }
    }
}

VB.NET

Imports DevExpress.Xpf.Charts
'...
Private Sub chartControl_BoundDataChanged(ByVal sender As Object, ByVal e As RoutedEventArgs)
    Dim series As SplineSeries2D = CType(diagram.Series(0), SplineSeries2D)
    If series.Points.Count > 0 Then
        For i As Integer = 0 To series.Points.Count - 1
            chartControl.Annotations.BeginInit()
            Dim annotation As Annotation = New Annotation() With {
                .Content = series.Points(i).Value.ToString()
            }
            annotation.AnchorPoint = New SeriesPointAnchorPoint() With {
                .SeriesPoint = series.Points(i)
            }
            annotation.ShapePosition = New RelativePosition() With {
                .Angle = 0,
                .ConnectorLength = 0
            }
            chartControl.Annotations.Add(annotation)
            chartControl.Annotations.EndInit()
        Next
    End If
End Sub

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the Annotation class.

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

how-to-anchor-annotations-to-various-points-t378313/CS/AnnotationExample/MainWindow.xaml#L32

<!--region #SeriesPointAnchorPoint-->
<dxc:Annotation Content="Annotation #1">
    <dxc:Annotation.AnchorPoint>

how-to-customize-chart-annotations-t376991/CS/MarsTemperature/MainWindow.xaml#L29

<dxc:ChartControl.Annotations>
    <dxc:Annotation Visible="True" Content="Annotation #1"
                    RuntimeAnchoring="True"

how-to-customize-annotation-content-t380028/CS/AnnotationExample/MainWindow.xaml#L36

<dxc:ChartControl.Annotations>
    <dxc:Annotation>
        <!--region #AnnotationContent-->

how-to-configure-the-appearance-of-an-annotation-t380122/CS/AnnotationSample/MainWindow.xaml#L19

<dxc:ChartControl.Annotations>
    <dxc:Annotation Margin="10">
        <dxc:Annotation.Content>

Inheritance

Show 11 items

Object

DispatcherObject

DependencyObject

Visual

UIElement

FrameworkElement

Control

ChartElementBase

ChartElement

DevExpress.Xpf.Charts.ChartNotificationElement

Annotation