Public Class InkThumbnail
    Inherits FrameworkElement

    Private sourceInkCanvas As InkCanvas = Nothing

    ' Get the InkCanvas that the user draws on.
    Public Property Source() As InkCanvas
        Get
            Return sourceInkCanvas
        End Get

        Set(ByVal Value As InkCanvas)

            If Not sourceInkCanvas Is Nothing Then

                ' Detach the event handler from the former InkCanvas.
                RemoveHandler sourceInkCanvas.StrokeCollected, AddressOf SourceChanged
            End If

            sourceInkCanvas = Value


            If Not sourceInkCanvas Is Nothing Then

                ' Attach the even handler to the InkCannvas
                AddHandler sourceInkCanvas.StrokeCollected, AddressOf SourceChanged
            End If

        End Set
    End Property

    ' Handle the StrokeCollection event of the InkCanvas.
    Private Sub SourceChanged(ByVal sender As Object, ByVal e As InkCanvasStrokeCollectedEventArgs)

        ' Cause the thumbnail to be redrawn.
        Me.InvalidateVisual()
    End Sub


    Protected Overrides Sub OnRender(ByVal drawingContext As DrawingContext)

        MyBase.OnRender(drawingContext)

        ' Draw the strokes from the InkCanvas at 1/4 of their size.
        drawingContext.PushTransform(New ScaleTransform(0.25, 0.25))

        If Not sourceInkCanvas Is Nothing Then
            sourceInkCanvas.Strokes.Draw(drawingContext)
        End If

    End Sub

End Class