HeatmapHitInfo.Axis Property

Returns the axis that is positioned in the test point.

Namespace: DevExpress.XtraCharts.Heatmap

Assembly: DevExpress.XtraCharts.v21.2.dll

NuGet Package: DevExpress.Charts

Declaration

C#

public HeatmapAxis Axis { get; }

VB.NET

Public ReadOnly Property Axis As HeatmapAxis

Property Value

Type	Description
HeatmapAxis	Contains heatmap axis options.

Remarks

Use the Axis property to access the axis located under the test point if the ChartHitInfo.InAxis property returns true. Note that if the InAxis is false, then the Axis property returns null (Nothing in Visual Basic).

Example

The following example shows how to determine what a heatmap element is in a test point, and collect information related to this element.

Call the HeatmapControl.CalcHitInfo method to obtain information about a specific point within the Heatmap Control. This method returns a HeatmapHitInfo object that contains information related to heatmap elements positioned in the test point.

C#

using DevExpress.Utils;
using DevExpress.XtraCharts;
using DevExpress.XtraCharts.Heatmap;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace HeatmapMatrixAdapterSample {
    public partial class Form1 : Form {
        HeatmapControl heatmap;
        ToolTipController toolTipController = new ToolTipController();
        public Form1() {
            InitializeComponent();
            //...
            heatmap.MouseMove += HeatmapMouseMove;
            heatmap.MouseLeave += HeatmapMouseLeave;
        }

        private void HeatmapMouseMove(object sender, MouseEventArgs e) {
            HeatmapHitInfo hitInfo = heatmap.CalcHitInfo(e.Location);
            StringBuilder builder = new StringBuilder();
            if (hitInfo.InAxis) {
                builder.AppendLine($"In axis: {hitInfo.Axis.Name}");
                if (hitInfo.AxisLabelItem != null)
                    builder.AppendLine($"  Label: {hitInfo.AxisLabelItem.Text}");
                if (hitInfo.AxisTitle != null)
                    builder.AppendLine($"  Axis title: {hitInfo.AxisTitle.Text}");
            }
            if (hitInfo.InCell)
                builder.AppendLine($" In cell: X ({hitInfo.Cell.XArgument}), Y ({hitInfo.Cell.YArgument})");
            if (hitInfo.InTitle)
                builder.AppendLine($" In title: {hitInfo.Title.Text}");
            if (hitInfo.InLegend)
                builder.AppendLine($" In legend");

            if (builder.Length > 0)
                toolTipController.ShowHint($"Hit-testing results:\n {builder}", heatmap.PointToScreen(e.Location));
            else
                toolTipController.HideHint();
        }
        private void HeatmapMouseLeave(object sender, System.EventArgs e) {
            toolTipController.HideHint();
        }
    }
}

VB.NET

Imports DevExpress.Utils
Imports DevExpress.XtraCharts
Imports DevExpress.XtraCharts.Heatmap
Imports System.Text
Imports System.Windows.Forms

Namespace HeatmapMatrixAdapterSample
    Public Partial Class Form1
        Inherits Form

        Private heatmap As HeatmapControl
        Private toolTipController As ToolTipController = New ToolTipController()

        Public Sub New()
            InitializeComponent()
            '...
            Me.heatmap.MouseMove += AddressOf HeatmapMouseMove
            Me.heatmap.MouseLeave += AddressOf HeatmapMouseLeave
        End Sub

        Private Sub HeatmapMouseMove(ByVal sender As Object, ByVal e As MouseEventArgs)
            Dim hitInfo As HeatmapHitInfo = heatmap.CalcHitInfo(e.Location)
            Dim builder As StringBuilder = New StringBuilder()

            If hitInfo.InAxis Then
                builder.AppendLine($"In axis: {hitInfo.Axis.Name}")
                If hitInfo.AxisLabelItem IsNot Nothing Then builder.AppendLine($"  Label: {hitInfo.AxisLabelItem.Text}")
                If hitInfo.AxisTitle IsNot Nothing Then builder.AppendLine($"  Axis title: {hitInfo.AxisTitle.Text}")
            End If

            If hitInfo.InCell Then builder.AppendLine($" In cell: X ({hitInfo.Cell.XArgument}), Y ({hitInfo.Cell.YArgument})")
            If hitInfo.InTitle Then builder.AppendLine($" In title: {hitInfo.Title.Text}")
            If hitInfo.InLegend Then builder.AppendLine($" In legend")

            If builder.Length > 0 Then
                toolTipController.ShowHint($"Hit-testing results:
 {builder}", heatmap.PointToScreen(e.Location))
            Else
                toolTipController.HideHint()
            End If
        End Sub

        Private Sub HeatmapMouseLeave(ByVal sender As Object, ByVal e As EventArgs)
            toolTipController.HideHint()
        End Sub
    End Class
End Namespace