wpf-devexpress-dot-xpf-dot-charts-dot-chartcontrol-dot-calchitinfo-x28-system-dot-windows-dot-point-x29.md
Returns information on the chart elements located at the specified point.
Namespace : DevExpress.Xpf.Charts
Assembly : DevExpress.Xpf.Charts.v25.2.dll
NuGet Package : DevExpress.Wpf.Charts
public ChartHitInfo CalcHitInfo(
Point point
)
Public Function CalcHitInfo(
point As Point
) As ChartHitInfo
| Name | Type | Description |
|---|---|---|
| point | Point |
A Point structure which specifies the test point coordinates relative to the chart’s top-left corner.
|
| Type | Description |
|---|---|
| ChartHitInfo |
A ChartHitInfo object, which contains information about the chart elements located at the test point.
|
Use the CalcHitInfo method to determine which element is located at the specified point. For instance, this can be used when handling the chart’s MouseDown event to determine which element was clicked. In such cases, pass the current mouse pointer’s coordinates as the method’s parameter.
This example demonstrates how to display custom information from the underlying data source in a custom tooltip for every data point.
To accomplish this, it is necessary to handle the chart’s MouseMove event, obtain the current SeriesPoint via the ChartControl.CalcHitInfo method, and if the series point is not null ( Nothing in Visual Basic), display a tooltip with its information.
Note that in addition to the MouseMove event, it is also necessary to handle the MouseLeave , to hide the tooltip when the mouse pointer is not over the chart.
If you wish to learn how to use built-in tooltips in your application, see the Tooltip topic.
<Window x:Class="DXChartsTooltips.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:dxc="http://schemas.devexpress.com/winfx/2008/xaml/charts"
Title="Window1" Height="313" Width="455">
<Grid>
<dxc:ChartControl Name="chartControl1" MouseMove="chartControl1_MouseMove"
MouseLeave="chartControl1_MouseLeave">
<dxc:ChartControl.Diagram>
<dxc:XYDiagram2D>
<dxc:XYDiagram2D.Series>
<dxc:BarSideBySideSeries2D DisplayName="My Series" ColorEach="True">
<dxc:BarSideBySideSeries2D.Points>
<dxc:SeriesPoint Argument="A" Value="1" />
<dxc:SeriesPoint Argument="B" Value="2" />
<dxc:SeriesPoint Argument="C" Value="6" />
<dxc:SeriesPoint Argument="D" Value="5" />
<dxc:SeriesPoint Argument="E" Value="3" />
</dxc:BarSideBySideSeries2D.Points>
</dxc:BarSideBySideSeries2D>
</dxc:XYDiagram2D.Series>
</dxc:XYDiagram2D>
</dxc:ChartControl.Diagram>
</dxc:ChartControl>
<Popup x:Name="tooltip1" AllowsTransparency="True">
<Border CornerRadius="9" Background="White" Padding="5"
BorderBrush="Black" BorderThickness="1" >
<TextBlock x:Name="tooltip_text" />
</Border>
</Popup>
</Grid>
</Window>
using System.Windows;
using System.Windows.Controls.Primitives;
using System.Windows.Input;
using DevExpress.Xpf.Charts;
namespace DXChartsTooltips {
public partial class Window1 : Window {
public Window1() {
InitializeComponent();
}
private void chartControl1_MouseMove(object sender, MouseEventArgs e) {
ChartHitInfo hitInfo = chartControl1.CalcHitInfo(e.GetPosition(chartControl1));
if (hitInfo != null && hitInfo.SeriesPoint != null) {
SeriesPoint point = hitInfo.SeriesPoint;
tooltip_text.Text = string.Format("Series = {0}\nArgument = {1}\nValue = {2}",
point.Series.DisplayName, point.Argument, point.Value);
tooltip1.Placement = PlacementMode.Mouse;
tooltip1.IsOpen = true;
Cursor = Cursors.Hand;
}
else {
tooltip1.IsOpen = false;
Cursor = Cursors.Arrow;
}
}
private void chartControl1_MouseLeave(object sender, MouseEventArgs e) {
tooltip1.IsOpen = false;
}
}
}
Imports Microsoft.VisualBasic
Imports System.Windows
Imports System.Windows.Controls.Primitives
Imports System.Windows.Input
Imports DevExpress.Xpf.Charts
Namespace DXChartsTooltips
Partial Public Class Window1
Inherits Window
Public Sub New()
InitializeComponent()
End Sub
Private Sub chartControl1_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs)
Dim hitInfo As ChartHitInfo = chartControl1.CalcHitInfo(e.GetPosition(chartControl1))
If hitInfo IsNot Nothing AndAlso hitInfo.SeriesPoint IsNot Nothing Then
Dim point As SeriesPoint = hitInfo.SeriesPoint
tooltip_text.Text = String.Format("Series = {0}" & Constants.vbLf & "Argument = {1}" & _
Constants.vbLf & "Value = {2}", point.Series.DisplayName, point.Argument, point.Value)
tooltip1.Placement = PlacementMode.Mouse
tooltip1.IsOpen = True
Cursor = Cursors.Hand
Else
tooltip1.IsOpen = False
Cursor = Cursors.Arrow
End If
End Sub
Private Sub chartControl1_MouseLeave(ByVal sender As Object, ByVal e As MouseEventArgs)
tooltip1.IsOpen = False
End Sub
End Class
End Namespace
The following code snippet (auto-collected from DevExpress Examples) contains a reference to the CalcHitInfo(Point) method.
Note
The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.
wpf-charts-display-custom-tooltips-over-the-data-point-hovered-by-the-mouse/CS/Window1.xaml.cs#L14
private void chartControl1_MouseMove(object sender, MouseEventArgs e) {
ChartHitInfo hitInfo = chartControl1.CalcHitInfo(e.GetPosition(chartControl1));
See Also