public class PostNetGenerator :
    BarCodeGeneratorBase

Public Class PostNetGenerator
    Inherits BarCodeGeneratorBase

using System;
using System.Collections.Generic;
using System.Drawing.Printing;
using System.Windows.Forms;
using DevExpress.XtraPrinting.BarCode;
using DevExpress.XtraReports.UI;
// ...
public XRBarCode CreatePostNetBarCode(string BarCodeText) {
    // Create a barcode control.
    XRBarCode barCode = new XRBarCode();

    // Set the barcode's type to PostNet.
    barCode.Symbology = new PostNetGenerator();

    // Adjust the barcode's main properties.
    barCode.Text = BarCodeText;
    barCode.Width = 400;
    barCode.Height = 100;

    return barCode;
}

Imports System
Imports System.Collections.Generic
Imports System.Drawing.Printing
Imports System.Windows.Forms
Imports DevExpress.XtraPrinting.BarCode
Imports DevExpress.XtraReports.UI
' ...
Public Function CreatePostNetBarCode(ByVal BarCodeText As String) As XRBarCode
    ' Create a barcode control.
    Dim barCode As New XRBarCode()

    ' Set the barcode's type to PostNet.
    barCode.Symbology = New PostNetGenerator()

    ' Adjust the barcode's main properties.
    barCode.Text = BarCodeText
    barCode.Width = 400
    barCode.Height = 100

    Return barCode
End Function