又來問了，這回是打印問題

Dim PrintDialog1 As New PrintDialog()
        PrintDialog1.Document = printdocument1
        Dim result As DialogResult = PrintDialog1.ShowDialog
        If (result = Windows.Forms.DialogResult.OK) Then
            printdocument1.Print()
        End If
我明明是按照書上打的居然出錯?