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ChartHitInfo.ConstantLine Property

Gets a constant line which is located under the test point.

Namespace: DevExpress.Xpf.Charts

Assembly: DevExpress.Xpf.Charts.v24.1.dll

NuGet Package: DevExpress.Wpf.Charts

Declaration

public ConstantLine ConstantLine { get; }

Property Value

Type Description
ConstantLine

A ConstantLine object, which represents the constant line located under the test point.

Remarks

Use the ConstantLine property to access the constant line located under the test point (if the ChartHitInfo.InConstantLine property returns true).

And, if ChartHitInfo.InConstantLine is false, the ConstantLine property returns null (Nothing in Visual Basic).

Example

This example demonstrates how to calculate the hit information for the chart element over which the mouse pointer is hovering.

To accomplish this, handle the ChartControl.MouseMove event, obtain the current chart element via the ChartControl.CalcHitInfo method, and if the element is not null (Nothing in Visual Basic), display its information.

using System.Windows;
using System.Windows.Input;
using DevExpress.Xpf.Charts;
using System.Text;

namespace DetermineHoveredChartElement
{

    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void chartControl1_MouseMove(object sender, MouseEventArgs e)
        {
            // Obtain hit information under the test point.
            ChartHitInfo hitInfo = chartControl1.CalcHitInfo(e.GetPosition(chartControl1));
            StringBuilder builder = new StringBuilder();

            // Check  whether the chart element is under the test point and if so - obtain the element's content.
            if (hitInfo.InDiagram)
                builder.AppendLine("In diagram");
            if (hitInfo.InAxis)
                builder.AppendLine("In axis:" + hitInfo.Axis.Name);
            if (hitInfo.AxisLabel != null)
                builder.AppendLine("Axis Label:\n" + hitInfo.AxisLabel.Name);
            if (hitInfo.AxisTitle != null)
                builder.AppendLine("Axis title:\n" + hitInfo.AxisTitle.Content);
            if (hitInfo.InTitle)
                builder.AppendLine("In chart title:\n " + hitInfo.Title.Content);
            if (hitInfo.InLegend)
                builder.AppendLine("In legend");
            if (hitInfo.InSeries)
                builder.AppendLine("In series: " + hitInfo.Series.Name);
            if (hitInfo.InSeriesLabel)
            {
                builder.AppendLine("In series label");
                builder.AppendLine("Series Label:" + hitInfo.SeriesLabel.Name);
            }

            if (hitInfo.InSeriesPoint)
            {
                builder.AppendLine("Argument: " + hitInfo.SeriesPoint.Argument);
                builder.AppendLine("Value: " + hitInfo.SeriesPoint.Value);
            }

            // Show hit-testing results 
            if (builder.Length > 0)
                text1.Content = string.Format("Hit-testing results:\n" + builder.ToString());
            else
                text1.Content = "Move the mouse\n pointer over\n the chart to see\n information on\n hovered chart\n elements.";
        }
    }
}
See Also