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AnnotationCollection.AddImageAnnotation(String, Image) Method

Appends the specified ImageAnnotation object to the current collection.

Namespace: DevExpress.XtraCharts

Assembly: DevExpress.XtraCharts.v22.2.dll

NuGet Package: DevExpress.Charts

Declaration

public ImageAnnotation AddImageAnnotation(
    string name,
    Image image
)

Parameters

Name Type Description
name String

A String value which specifies the name of the annotation.

image Image

An Image object representing the annotation’s image.

Returns

Type Description
ImageAnnotation

An ImageAnnotation object representing the image annotation to be added.

Remarks

Use the AddImageAnnotation method to create an image annotation within a ChartControl. For a WebChartControl, use the overloaded AddImageAnnotation method with the imageUrl parameter.

After an annotation is added to an element’s collection, it can be accessed via the corresponding property of this element (ChartControl.Annotations, XYDiagramPaneBase.Annotations, or SeriesPoint.Annotations). Alternatively, to centrally access all annotations that are present in a chart control, use the ChartControl.AnnotationRepository property.

When you use the AddImageAnnotation method to add annotations to the XYDiagramPaneBase.Annotations or SeriesPoint.Annotations collections, this automatically anchors the annotation to the pane or the series point (the annotation’s AnchorPoint property is initialized with a PaneAnchorPoint or SeriesPointAnchorPoint object).

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

Chart annotations

#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

    }
}
See Also