RelativePosition Class
Provides settings for positioning of annotation objects in relation to their anchor points.
Namespace: DevExpress.XtraCharts
Assembly: DevExpress.XtraCharts.v21.2.dll
NuGet Package: DevExpress.Charts
Declaration
Remarks
If the Annotation.ShapePosition property is set to the RelativePosition type, you can specify the annotation’s angle at its anchor point (RelativePosition.Angle), and the length of its connecting line (RelativePosition.ConnectorLength).
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/winforms-chart-accompany-chart-elements-by-text-or-image-annotations
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;
}