ImageAnnotation Class

Represents an image annotation.

Namespace: DevExpress.XtraCharts

Assembly: DevExpress.XtraCharts.v24.2.dll

Declaration

C#

public class ImageAnnotation :
    Annotation,
    IDisposable

VB.NET

Public Class ImageAnnotation
    Inherits Annotation
    Implements IDisposable

Related API Members

The following members return ImageAnnotation objects:

• AnnotationCollection.AddImageAnnotation()
• AnnotationCollection.AddImageAnnotation(String, DXImage)
• AnnotationCollection.AddImageAnnotation(String, String)
• AnnotationCollection.AddImageAnnotation(String)

Remarks

There are two kinds of annotations available in XtraCharts - text annotations (represented by TextAnnotation objects), and image annotations (represented by ImageAnnotation objects).

To create an annotation of the required type, use the AnnotationCollection.AddTextAnnotation and AnnotationCollection.AddImageAnnotation methods.

To specify an image for an ImageAnnotation object, use its ImageAnnotation.Image property. And, to control the size of the image, use the ImageAnnotation.SizeMode property.

For more information, refer to Annotations.

Example

The following example demonstrates how to create text and image annotations and anchor them to a chart, its pane, and a series point.

View Example

Form1.cs

#region #usings
using System;
using System.Drawing;
using System.IO;
using System.Windows.Forms;
using DevExpress.Drawing;
using DevExpress.XtraCharts;
// ...
#endregion #usings

namespace AnnotationsSample {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }

        #region #generalcode
        private void Form1_Load(object sender, EventArgs e) {
            // Add a text annotation to the chart control's repository.
            chartControl1.AnnotationRepository.Add(new TextAnnotation("Annotation 1"));

            // And, assign a series point to the annotation's AnchorPoint property.
            // This adds the annotation to the series point's Annotations collection.
            chartControl1.AnnotationRepository[0].AnchorPoint =
                new SeriesPointAnchorPoint(chartControl1.Series[0].Points[2]);

            // Now, create an image annotation, and add it to the chart's collection.
            chartControl1.Annotations.AddImageAnnotation("Annotation 2",
                DXImage.FromStream(new FileStream(@"...\...\image.png", FileMode.Open, FileAccess.Read, FileShare.Read)));

            // Define the X and Y absolute coordinates for the annotation, in pixels.
            ((ChartAnchorPoint)chartControl1.Annotations[0].AnchorPoint).X = 150;
            ((ChartAnchorPoint)chartControl1.Annotations[0].AnchorPoint).Y = 150;

            // Obtain the additional pane from the diagram's collection.
            XYDiagramPaneBase myPane = ((XYDiagram)chartControl1.Diagram).Panes[0];

            // And, position the chart's annotation in this pane's right top corner;
            ((FreePosition)chartControl1.Annotations[0].ShapePosition).DockTarget = myPane;
            ((FreePosition)chartControl1.Annotations[0].ShapePosition).DockCorner = DockCorner.RightTop;

            // Another annotation is now being added to the collection of this pane.
            myPane.Annotations.AddImageAnnotation("Annotation 3",
                DXImage.FromStream(new FileStream(@"...\...\image.png", FileMode.Open, FileAccess.Read, FileShare.Read)));

            // Define its axis coordinates (in units appropriate for the scale type of the axes).
            ((PaneAnchorPoint)myPane.Annotations[0].AnchorPoint).AxisXCoordinate.AxisValue = 2;
            ((PaneAnchorPoint)myPane.Annotations[0].AnchorPoint).AxisYCoordinate.AxisValue = 180;

            // Position the annotation in relation to its anchor point.
            ((RelativePosition)myPane.Annotations[0].ShapePosition).Angle = -135;
            ((RelativePosition)myPane.Annotations[0].ShapePosition).ConnectorLength = 50;

            // You can get an annotation either via the collection of the element to which it is anchored,
            // or centrally, via the chart control's repository (e.g. by its name).
            TextAnnotation myTextAnnotation =
                (TextAnnotation)chartControl1.AnnotationRepository.GetElementByName("Annotation 1");
            ImageAnnotation myImageAnnotation =
                (ImageAnnotation)chartControl1.AnnotationRepository.GetElementByName("Annotation 3");

            // Define the text for the text annotation.
            myTextAnnotation.Text = "<i>Basic</i> <b>HTML</b> <u>is</u> <color=blue>supported</color>.";

            // Enable the interactive positioning for the image annotation.
            myImageAnnotation.RuntimeMoving = true;
            myImageAnnotation.RuntimeAnchoring = true;
            myImageAnnotation.RuntimeResizing = true;
            myImageAnnotation.RuntimeRotation = true;

            // Specify image annotation size mode.
            myImageAnnotation.SizeMode = ChartImageSizeMode.Tile;

            // And, adjust image annotation appearance options.
            myImageAnnotation.ShapeKind = ShapeKind.RoundedRectangle;
            myImageAnnotation.ShapeFillet = 10;
            myImageAnnotation.ConnectorStyle = AnnotationConnectorStyle.Arrow;
        }
        #endregion #generalcode

    }
}

Form1.vb

#Region "#usings"
Imports System
Imports System.Drawing
Imports System.IO
Imports System.Windows.Forms
Imports DevExpress.Drawing
Imports DevExpress.XtraCharts

' ...
#End Region  ' #usings
Namespace AnnotationsSample

    Public Partial Class Form1
        Inherits Form

        Public Sub New()
            InitializeComponent()
        End Sub

#Region "#generalcode"
        Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
            ' Add a text annotation to the chart control's repository.
            chartControl1.AnnotationRepository.Add(New TextAnnotation("Annotation 1"))
            ' And, assign a series point to the annotation's AnchorPoint property.
            ' This adds the annotation to the series point's Annotations collection.
            chartControl1.AnnotationRepository(0).AnchorPoint = New SeriesPointAnchorPoint(chartControl1.Series(0).Points(2))
            ' Now, create an image annotation, and add it to the chart's collection.
            chartControl1.Annotations.AddImageAnnotation("Annotation 2", DXImage.FromStream(New FileStream("...\...\image.png", FileMode.Open, FileAccess.Read, FileShare.Read)))
            ' Define the X and Y absolute coordinates for the annotation, in pixels.
            CType(chartControl1.Annotations(0).AnchorPoint, ChartAnchorPoint).X = 150
            CType(chartControl1.Annotations(0).AnchorPoint, ChartAnchorPoint).Y = 150
            ' Obtain the additional pane from the diagram's collection.
            Dim myPane As XYDiagramPaneBase = CType(chartControl1.Diagram, XYDiagram).Panes(0)
            ' And, position the chart's annotation in this pane's right top corner;
            CType(chartControl1.Annotations(0).ShapePosition, FreePosition).DockTarget = myPane
            CType(chartControl1.Annotations(0).ShapePosition, FreePosition).DockCorner = DockCorner.RightTop
            ' Another annotation is now being added to the collection of this pane.
            myPane.Annotations.AddImageAnnotation("Annotation 3", DXImage.FromStream(New FileStream("...\...\image.png", FileMode.Open, FileAccess.Read, FileShare.Read)))
            ' Define its axis coordinates (in units appropriate for the scale type of the axes).
            CType(myPane.Annotations(0).AnchorPoint, PaneAnchorPoint).AxisXCoordinate.AxisValue = 2
            CType(myPane.Annotations(0).AnchorPoint, PaneAnchorPoint).AxisYCoordinate.AxisValue = 180
            ' Position the annotation in relation to its anchor point.
            CType(myPane.Annotations(0).ShapePosition, RelativePosition).Angle = -135
            CType(myPane.Annotations(0).ShapePosition, RelativePosition).ConnectorLength = 50
            ' You can get an annotation either via the collection of the element to which it is anchored,
            ' or centrally, via the chart control's repository (e.g. by its name).
            Dim myTextAnnotation As TextAnnotation = CType(chartControl1.AnnotationRepository.GetElementByName("Annotation 1"), TextAnnotation)
            Dim myImageAnnotation As ImageAnnotation = CType(chartControl1.AnnotationRepository.GetElementByName("Annotation 3"), ImageAnnotation)
            ' Define the text for the text annotation.
            myTextAnnotation.Text = "<i>Basic</i> <b>HTML</b> <u>is</u> <color=blue>supported</color>."
            ' Enable the interactive positioning for the image annotation.
            myImageAnnotation.RuntimeMoving = True
            myImageAnnotation.RuntimeAnchoring = True
            myImageAnnotation.RuntimeResizing = True
            myImageAnnotation.RuntimeRotation = True
            ' Specify image annotation size mode.
            myImageAnnotation.SizeMode = ChartImageSizeMode.Tile
            ' And, adjust image annotation appearance options.
            myImageAnnotation.ShapeKind = ShapeKind.RoundedRectangle
            myImageAnnotation.ShapeFillet = 10
            myImageAnnotation.ConnectorStyle = AnnotationConnectorStyle.Arrow
        End Sub
#End Region  ' #generalcode
    End Class
End Namespace

Inheritance

Object

ChartElement

ChartElementNamed

Annotation

ImageAnnotation