C# Barcode Reader in ASP.NET framework web form app

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Index.aspx.cs" Inherits="OnBarcodeReaderASPNETWebDemo.Index" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>OnBarcode Reader ASP.NET Web Demo</title>
</head>
<body>
    <form id="form1" runat="server" enctype="multipart/form-data">
        <div style="text-align:center">
            <br /><br />
            <asp:FileUpload ID="FileUpload1" runat="server" />
            &nbsp;&nbsp;
            Barcode Type:
            &nbsp;
            <asp:DropDownList ID="dropDownListBarcodeType" runat="server" AutoPostBack="true" />
            <br /><br />
            <asp:Button ID="UploadToScan" runat="server" Text="Scan Image" OnClick="UploadToScan_Click" />
            <br /><br />
            Scan Result:
            <br />
            <asp:TextBox ID="ScanResult" runat="server" Text="" Width="500" Height="100" TextMode="MultiLine" ReadOnly="true" />
        </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using OnBarcode.Barcode.BarcodeScanner;

namespace OnBarcodeReaderASPNETWebDemo
{
    public partial class Index : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!this.IsPostBack)
            {
                String[] types = new String[] {
                    "AustraliaPost", "Codabar", "Code39", "Code39Extension", "Code93",
                    "Code128", "DataMatrix", "EAN8", "EAN13", "Identcode",
                    "IntelligentMail", "Interleaved2of5", "ISBN", "ISSN", "ITF14",
                    "Leitcode", "PatchCode", "PDF417", "Planet", "Postnet",
                    "QRCode", "RM4SCC", "UPCA", "UPCE"            
                };
                this.dropDownListBarcodeType.DataSource = types;
                this.dropDownListBarcodeType.DataBind();
                //  Default Barcode Type: Code 128
                this.dropDownListBarcodeType.SelectedIndex = 5;
            }
        }

        protected void UploadToScan_Click(object sender, EventArgs e)
        {
            if (!this.FileUpload1.HasFile)
                return;

            try
            {
                String filename = Path.GetFileName(this.FileUpload1.FileName);

                StringBuilder sb = new StringBuilder();
                using (MemoryStream ms = new MemoryStream(this.FileUpload1.FileBytes))
                {
                    //  Get enum BarcodeType from ComboBox selected index.
                    BarcodeType barcodeType = (BarcodeType)this.dropDownListBarcodeType.SelectedIndex;

                    String[] result = BarcodeScanner.Scan(ms, barcodeType);
                    if (result.Length > 0)
                    {
                        sb.Append("Number of Barcode: " + result.Length + "\r\n");
                        foreach (String s in result)
                            sb.Append("Message: '" + s + "'\r\n");
                    }
                    else
                    {
                        sb.Append("No Barcode Found.");
                    }
                }

                this.ScanResult.Text = sb.ToString();
            }
            catch (Exception ex)
            {
                this.ScanResult.Text = "Error: " + ex.Message;
            }
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>

<!--
  For more information on how to configure your ASP.NET application, please visit
  https://go.microsoft.com/fwlink/?LinkId=169433
  -->

<configuration>
    <system.web>
      <compilation debug="true" targetFramework="4.0" />
    </system.web>


    <system.webServer>
      <defaultDocument>
        <files>
          <clear />
           <add value="Index.aspx" />
        </files>
      </defaultDocument>
    </system.webServer>


</configuration>