''' <summary>
''' Changes the user-default PrintTicket setting of the specified print queue.
''' </summary>
''' <param name="queue">the printer whose user-default PrintTicket setting needs to be changed</param>
Private Shared Sub ChangePrintTicketSetting(ByVal queue As PrintQueue)
    '
    ' Obtain the printer's PrintCapabilities so we can determine whether or not
    ' duplexing printing is supported by the printer.
    '
    Dim printcap As PrintCapabilities = queue.GetPrintCapabilities()

    '
    ' The printer's duplexing capability is returned as a read-only collection of duplexing options
    ' that can be supported by the printer. If the collection returned contains the duplexing
    ' option we want to set, it means the duplexing option we want to set is supported by the printer,
    ' so we can make the user-default PrintTicket setting change.
    '
    If printcap.DuplexingCapability.Contains(Duplexing.TwoSidedLongEdge) Then
        '
        ' To change the user-default PrintTicket, we can first create a delta PrintTicket with
        ' the new duplexing setting.
        '
        Dim deltaTicket As New PrintTicket()
        deltaTicket.Duplexing = Duplexing.TwoSidedLongEdge

        '
        ' Then merge the delta PrintTicket onto the printer's current user-default PrintTicket,
        ' and validate the merged PrintTicket to get the new PrintTicket we want to set as the
        ' printer's new user-default PrintTicket.
        '
        Dim result As ValidationResult = queue.MergeAndValidatePrintTicket(queue.UserPrintTicket, deltaTicket)

        '
        ' The duplexing option we want to set could be constrained by other PrintTicket settings
        ' or device settings. We can check the validated merged PrintTicket to see whether the
        ' the validation process has kept the duplexing option we want to set unchanged.
        '
        If result.ValidatedPrintTicket.Duplexing = Duplexing.TwoSidedLongEdge Then
            '
            ' Set the printer's user-default PrintTicket and commit the set operation.
            '
            queue.UserPrintTicket = result.ValidatedPrintTicket
            queue.Commit()
            Console.WriteLine("PrintTicket new duplexing setting is set on '{0}'.", queue.FullName)
        Else
            '
            ' The duplexing option we want to set has been changed by the validation process
            ' when it was resolving setting constraints.
            '
            Console.WriteLine("PrintTicket new duplexing setting is constrained on '{0}'.", queue.FullName)
        End If
    Else
        '
        ' If the printer doesn't support the duplexing option we want to set, skip it.
        '
        Console.WriteLine("PrintTicket new duplexing setting is not supported on '{0}'.", queue.FullName)
    End If
End Sub