Wpf VB.NET print preview CANVAS

See more:

VB

WPF

Canvas

print

<Canvas Grid.Column="0" Name="_printcanvas" >
               <Ellipse Fill="Gainsboro" Canvas.Left="25" Canvas.Top="25" Width="174" Height="175" />
               <Rectangle Fill="LightBlue" Canvas.Left="25" Canvas.Top="25" Width="50" Height="50" />
               <Rectangle Fill="LightCoral" Canvas.Left="50" Canvas.Top="50" Width="50" Height="50" />
               <Rectangle Fill="LightCyan" Canvas.Left="75" Canvas.Top="75" Width="50" Height="50" />
               <Label x:Name="client_name" Content="Label" Canvas.Left="10" Canvas.Top="200"/>
           </Canvas>

Private Sub PrintPv_Click(sender As Object, e As RoutedEventArgs) Handles PrintPv.Click
        Dim printPVdialog As New System.Windows.Forms.PrintPreviewDialog
        printPVdialog.ShowDialog()
  End Sub

but it's empty.
izit need to add canvas into printPVdialog.Document?
is able to do like this?

What I have tried:

If printDialog.ShowDialog() = True Then
printDialog.PrintVisual(_printcanvas, "A Scaled Drawing")
End If

I have try this but this can't preview