TextAnnotation Class
Represents a text annotation.
Namespace: DevExpress.XtraCharts
Assembly: DevExpress.XtraCharts.v19.1.dll
Declaration
public class TextAnnotation :
Annotation,
ITextPropertiesProvider,
IHitTest,
ISupportTextAntialiasing,
ITextAppearance
Related API Members
The following members return TextAnnotation 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 the text for a TextAnnotation object, use its TextAnnotation.Text property. And, to control the annotation’s size, use its TextAnnotation.AutoSize property.
For more information, refer to Annotations.
Example
This example demonstrates how text and image annotations can be created and anchored to a chart, pane or series point.
Note
A complete sample project is available at https://github.com/DevExpress-Examples/how-to-accompany-a-chart-its-pane-or-series-point-by-text-or-image-annotations-e2188
using System;
using System.Drawing;
using System.Windows.Forms;
using DevExpress.XtraCharts;
// ...
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",
Bitmap.FromFile(@"...\...\image.png"));
// 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", Bitmap.FromFile(@"...\...\image.png"));
// 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;
}