How to: Add a Constant Line to an Axis
- 2 minutes to read
This example demonstrates how a constant line can be created and customized at runtime.
Since constant lines belong to a diagram’s axis, it’s first required to cast your diagram object to the appropriate diagram’s type. After that, it’s possible to access axes and manage their constant lines collection.
// Cast the chart's diagram to the XYDiagram type, to access its axes. XYDiagram diagram = (XYDiagram)chartControl1.Diagram; // Create a constant line. ConstantLine constantLine1 = new ConstantLine("Constant Line 1"); diagram.AxisY.ConstantLines.Add(constantLine1); // Define its axis value. constantLine1.AxisValue = 7; // Customize the behavior of the constant line. constantLine1.Visible = true; constantLine1.ShowInLegend = true; constantLine1.LegendText = "Some Threshold"; constantLine1.ShowBehind = false; // Customize the constant line's title. constantLine1.Title.Visible = true; constantLine1.Title.Text = "Constant Line Title"; constantLine1.Title.TextColor = Color.Red; constantLine1.Title.Antialiasing = false; constantLine1.Title.Font = new Font("Tahoma", 14, FontStyle.Bold); constantLine1.Title.ShowBelowLine = true; constantLine1.Title.Alignment = ConstantLineTitleAlignment.Far; // Customize the appearance of the constant line. constantLine1.Color = Color.Red; constantLine1.LineStyle.DashStyle = DashStyle.Dash; constantLine1.LineStyle.Thickness = 2;
The result is shown in the following image.
A complete sample project is available in the DevExpress Code Examples database at https://supportcenter.devexpress.com/ticket/details/e1370/how-to-add-a-constant-line-to-an-axis.