ImageAnnotation Class
Represents an image annotation.
Namespace: DevExpress.XtraCharts
Assembly: DevExpress.XtraCharts.v23.2.dll
NuGet Package: DevExpress.Charts
Declaration
Related API Members
The following members return ImageAnnotation objects:
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.
#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
}
}