wpf-devexpress-dot-xpf-dot-charts-dot-charthitinfo-e271403e.md
Gets a constant line which is located under the test point.
Namespace : DevExpress.Xpf.Charts
Assembly : DevExpress.Xpf.Charts.v25.2.dll
NuGet Package : DevExpress.Wpf.Charts
public ConstantLine ConstantLine { get; }
Public ReadOnly Property ConstantLine As ConstantLine
| Type | Description |
|---|---|
| ConstantLine |
A ConstantLine object, which represents the constant line located under the test point.
|
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).
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.";
}
}
}
<Window x:Class="DetermineHoveredChartElement.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525"
xmlns:dxc="http://schemas.devexpress.com/winfx/2008/xaml/charts">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="130"/>
<ColumnDefinition />
</Grid.ColumnDefinitions>
<StackPanel Grid.Row="0" Grid.Column="0" >
<Label Name="text1"/>
</StackPanel>
<dxc:ChartControl Grid.Row="0" Grid.Column="1" Name="chartControl1"
CrosshairEnabled="False"
MouseMove="chartControl1_MouseMove">
<dxc:XYDiagram2D >
<dxc:BarSideBySideSeries2D x:Name="series1" LabelsVisibility="True"
DisplayName="Series1">
<dxc:SeriesPoint Argument="A" Value="1" />
<dxc:SeriesPoint Argument="B" Value="2" />
<dxc:SeriesPoint Argument="C" Value="3" />
<dxc:SeriesPoint Argument="D" Value="4" />
</dxc:BarSideBySideSeries2D>
<dxc:BarSideBySideSeries2D x:Name="series2" LabelsVisibility="True"
DisplayName="Series2">
<dxc:SeriesPoint Argument="A" Value="4" />
<dxc:SeriesPoint Argument="B" Value="3" />
<dxc:SeriesPoint Argument="C" Value="2" />
<dxc:SeriesPoint Argument="D" Value="1" />
</dxc:BarSideBySideSeries2D>
<dxc:XYDiagram2D.AxisY>
<dxc:AxisY2D >
<dxc:AxisY2D.Title>
<dxc:AxisTitle Content="AxisY Title"/>
</dxc:AxisY2D.Title>
<dxc:AxisY2D.Label>
<dxc:AxisLabel Name="AxisYLabel" />
</dxc:AxisY2D.Label>
</dxc:AxisY2D>
</dxc:XYDiagram2D.AxisY>
<dxc:XYDiagram2D.AxisX>
<dxc:AxisX2D>
<dxc:AxisX2D.Label>
<dxc:AxisLabel Name="AxisXLabel"/>
</dxc:AxisX2D.Label>
</dxc:AxisX2D>
</dxc:XYDiagram2D.AxisX>
</dxc:XYDiagram2D>
<dxc:ChartControl.Titles>
<dxc:Title Content="My Chart" />
</dxc:ChartControl.Titles>
<dxc:ChartControl.Legend>
<dxc:Legend />
</dxc:ChartControl.Legend>
</dxc:ChartControl>
</Grid>
</Window>
Imports Microsoft.VisualBasic
Imports System.Windows
Imports System.Windows.Input
Imports DevExpress.Xpf.Charts
Imports System.Text
Namespace DetermineHoveredChartElement
Partial Public Class MainWindow
Inherits Window
Public Sub New()
InitializeComponent()
End Sub
Private Sub chartControl1_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs)
' Obtain hit information under the test point.
Dim hitInfo As ChartHitInfo = chartControl1.CalcHitInfo(e.GetPosition(chartControl1))
Dim builder As New StringBuilder()
' Check whether the chart element is under the test point and if so - obtain the element's content.
If hitInfo.InDiagram Then
builder.AppendLine("In diagram")
End If
If hitInfo.InAxis Then
builder.AppendLine("In axis:" & hitInfo.Axis.Name)
End If
If hitInfo.AxisLabel IsNot Nothing Then
builder.AppendLine("Axis Label:" & Constants.vbLf + hitInfo.AxisLabel.Name)
End If
If hitInfo.AxisTitle IsNot Nothing Then
builder.AppendLine("Axis title:" & Constants.vbLf + hitInfo.AxisTitle.Content)
End If
If hitInfo.InTitle Then
builder.AppendLine("In chart title:" & Constants.vbLf & " " & hitInfo.Title.Content)
End If
If hitInfo.InLegend Then
builder.AppendLine("In legend")
End If
If hitInfo.InSeries Then
builder.AppendLine("In series: " & hitInfo.Series.Name)
End If
If hitInfo.InSeriesLabel Then
builder.AppendLine("In series label")
builder.AppendLine("Series Label:" & hitInfo.SeriesLabel.Name)
End If
If hitInfo.InSeriesPoint Then
builder.AppendLine("Argument: " & hitInfo.SeriesPoint.Argument)
builder.AppendLine("Value: " & hitInfo.SeriesPoint.Value)
End If
' Show hit-testing results
If builder.Length > 0 Then
text1.Content = String.Format("Hit-testing results:" & Constants.vbLf + builder.ToString())
Else
text1.Content = "Move the mouse" & Constants.vbLf & " pointer over" & Constants.vbLf & " the chart to see" & Constants.vbLf & " information on" & Constants.vbLf & " hovered chart" & Constants.vbLf & " elements."
End If
End Sub
End Class
End Namespace
See Also