ChartAnchorPoint Class
The annotation is anchored to the chart.
Namespace: DevExpress.XtraCharts
Assembly: DevExpress.XtraCharts.v19.2.dll
Declaration
Remarks
If the Annotation.AnchorPoint property is set to the ChartAnchorPoint type, the annotation is added to the chart’s collection, returned by its ChartControl.Annotations property.
Then, you can adjust the annotations position on the chart’s surface, by specifying its distance from the chart’s left and top edges, via the ChartAnchorPoint.X and ChartAnchorPoint.Y properties. These coordinates position an annotation absolutely, meaning that the anchor point doesn’t change when a chart is being resized.
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;
}