How to send contents of groupbox to printer

Question

I have a groupbox that has some controls in it and i want to send it to printer.

I have this code thats builds the bmp file from the groupbox. How can i sent it to printer at button click?

Private Sub Doc_PrintPage(sender As Object, e As PrintPageEventArgs)
    Dim x As Single = e.MarginBounds.Left
    Dim y As Single = e.MarginBounds.Top
    Dim bmp As New Bitmap(Me.GroupBox1.Width, Me.GroupBox1.Height)
    Me.GroupBox1.DrawToBitmap(bmp, New Rectangle(0, 0, Me.GroupBox1.Width, Me.GroupBox1.Height))
    e.Graphics.DrawImage(DirectCast(bmp, Image), x, y)
End Sub

I have in button click event:

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim doc As New PrintDocument()
    doc = Doc_PrintPage()
    Dim dlgSettings As New PrintDialog()
    dlgSettings.Document = doc
    If dlgSettings.ShowDialog() = DialogResult.OK Then
        doc.Print()
    End If
End Sub

Final working code after advices:

 Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    BMP = New Bitmap(GroupBox1.Width, GroupBox1.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb)
    GroupBox1.DrawToBitmap(BMP, New Rectangle(0, 0, GroupBox1.Width, GroupBox1.Height))
    Dim pd As New PrintDocument
    Dim pdialog As New PrintDialog
    AddHandler pd.PrintPage, (Sub(s, args)
                                  args.Graphics.DrawImage(BMP, 0, 0)
                                  args.HasMorePages = False
                              End Sub)
    pdialog.ShowDialog()
    pd.PrinterSettings.PrinterName = pdialog.PrinterSettings.PrinterName
    pd.Print()
End Sub

Answer 1

The idea is that you have a PrintDocument object, you call its Print method, it raises its PrintPage event, you handle that event and in the handler method you use GDI+ to draw whatever is to be printed. So, you need to get rid of this line:

doc = Doc_PrintPage()

What could that possibly be doing? You are trying to assign the result of a method to a PrintDocument variable. In order for that to be meaningful, the method would have to return a PrintDocument object, which it doesn't. What you need to do is register that method to handle the PrintPage event of your PrintDocument:

AddHandler doc.PrintPage, AddressOf Doc_PrintPage

If you do that then you need to remove the handler as well. A better option would be to add all your printing objects to the form in the designer and then create a PrintPage event handler for the PrintDocument just as you would create event handlers for a Button or a TextBox.

For more info on printing, you may find this useful.