Private WithEvents inkCanvas1 As New InkCanvas()
Private inkDA As DrawingAttributes
Private highlighterDA As DrawingAttributes
Private useHighlighter As Boolean = False

' Add an InkCanvas to the window, and allow the user to 
' switch between using a green pen and a purple highlighter 
' on the InkCanvas.
Private Sub WindowLoaded(ByVal sender As Object, ByVal e As RoutedEventArgs)

    inkCanvas1.Background = Brushes.DarkSlateBlue
    inkCanvas1.DefaultDrawingAttributes.Color = Colors.SpringGreen

    ' Add the InkCanvas to the DockPanel, named root.
    root.Children.Add(inkCanvas1)

    ' Set up the DrawingAttributes for the pen.
    inkDA = New DrawingAttributes()
    With inkDA
        .Color = Colors.SpringGreen
        .Height = 5
        .Width = 5
        .FitToCurve = True
    End With

    ' Set up the DrawingAttributes for the highlighter.
    highlighterDA = New DrawingAttributes()
    With highlighterDA
        .Color = Colors.Orchid
        .IsHighlighter = True
        .IgnorePressure = True
        .StylusTip = StylusTip.Rectangle
        .Height = 30
        .Width = 10
    End With

    inkCanvas1.DefaultDrawingAttributes = inkDA

End Sub


' Create a button called switchHighlighter and use 
' SwitchHighlighter_Click to handle the Click event.  
' The useHighlighter variable is a boolean that indicates
' whether the InkCanvas renders ink as a highlighter.

' Switch between using the 'pen' DrawingAttributes and the 
' 'highlighter' DrawingAttributes when the user clicks on .
Private Sub SwitchHighlighter_Click(ByVal sender As [Object], ByVal e As RoutedEventArgs)

    useHighlighter = Not useHighlighter

    If useHighlighter Then
        switchHighlighter.Content = "Use Pen"
        inkCanvas1.DefaultDrawingAttributes = highlighterDA
    Else

        switchHighlighter.Content = "Use Highlighter"
        inkCanvas1.DefaultDrawingAttributes = inkDA
    End If

End Sub