Add Tooltip to Data Point

Question

Hi,
I was wondering is it possible to add a Tooltip containing text (not the (X,Y) values) to a datapoint. I'm using VS2010.

Answer 1

This example uses a structure to associate a text string with each data point.
Imports System.Windows.Forms.DataVisualization.Charting
Public Class Form2
Structure myData
Public y As Single
Public text As String
End Structure
Private MyDataList As New List(Of myData)
Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim d As myData
For i = 1 To 12
d.y = 5 * Math.Sin(i / 2)
d.text = "Text Data: " & i.ToString
MyDataList.Add(d)
Next
Label1.Text = "Select a Point"
'setup the chart
With Chart1.ChartAreas(0)
.AxisX.Title = "Time"
.AxisX.MajorGrid.LineColor = Color.LightBlue
.AxisX.Minimum = 0
.AxisX.Maximum = 14
.AxisX.Interval = 2
.AxisX.LabelStyle.IsEndLabelVisible = False
.AxisY.Title = "Value"
.AxisY.MajorGrid.LineColor = Color.LightGray
.AxisY.Minimum = -6
.AxisY.Maximum = 6
.AxisY.Interval = 2
.BackColor = Color.AntiqueWhite
.BackSecondaryColor = Color.White
.BackGradientStyle = GradientStyle.HorizontalCenter
.BorderColor = Color.Blue
.BorderDashStyle = ChartDashStyle.Solid
.BorderWidth = 1
.ShadowOffset = 2
End With
Chart1.Series.Clear()
Chart1.Series.Add("Monthy Data")
With Chart1.Series(0)
.ChartType = DataVisualization.Charting.SeriesChartType.Line
.BorderWidth = 2
.Color = Color.Blue
.MarkerStyle = DataVisualization.Charting.MarkerStyle.Circle
.MarkerSize = 8
.IsVisibleInLegend = False
For m = 1 To 12
.Points.AddXY(m, MyDataList(m - 1).y)
Next
End With
End Sub
Private Sub Chart1_MouseDown(sender As Object, e As MouseEventArgs) Handles Chart1.MouseDown
Dim result As HitTestResult = Chart1.HitTest(e.X, e.Y)
If result.ChartElementType = ChartElementType.DataPoint Then
Chart1.Series(0).Points(result.PointIndex).XValue.ToString()
Label1.Text = MyDataList(result.PointIndex).text
Else
If result.ChartElementType <> ChartElementType.Nothing Then
Dim elementType As String = result.ChartElementType.ToString()
Label1.Text = "Selected Element is: " & elementType
End If
End If
End Sub
Private Sub Chart1_MouseMove(sender As Object, e As MouseEventArgs) Handles Chart1.MouseMove
Dim result As HitTestResult = Chart1.HitTest(e.X, e.Y)
' If a Data Point or a Legend item is selected.
If result.ChartElementType = ChartElementType.DataPoint Or result.ChartElementType = ChartElementType.LegendItem Then
' Set cursor type
Me.Cursor = Cursors.Hand
Else
If result.ChartElementType <> ChartElementType.Nothing And result.ChartElementType <> ChartElementType.PlottingArea Then
' Set cursor type
Me.Cursor = Cursors.Hand
Else
' Set default cursor
Me.Cursor = Cursors.Default
End If
End If
End Sub
End Class