C# Barcode Reader Library in ASP.NET Core MVC web app

namespace OnBarcodeReaderASPNETCoreMVCDemo.Models
{
    public class IndexViewModel
    {
        public List<String> BarcodeTypes { get; set; } = new List<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"
        };
        public int SelectedTypeIndex { get; set; }
        public IFormFile? FormFile { get; set; }
    }
}

namespace OnBarcodeReaderASPNETCoreMVCDemo.Models
{
    public class ShowResultViewModel
    {
        public String[]? DataMessages { get; set; }
    }
}

@model IndexViewModel;
@{
    ViewData["Title"] = "Home Page";
}

<div class="text-center">
    <br />
    <form asp-action="ShowResult" method="post" enctype="multipart/form-data">
        <input Name="FormFile" type="file" style="width:300px; "
               onchange="document.getElementById('Submit').removeAttribute('disabled')" />
        &nbsp;&nbsp;
        Barcode Type:
        <select asp-for="SelectedTypeIndex"
                asp-items="Model.BarcodeTypes.Select((item, index) => new SelectListItem {
                    Text = item, Value = index.ToString(), Selected = index == Model.SelectedTypeIndex })">
        </select>
        <br /><br />
        <input id="Submit" type="submit" value="Scan Image" disabled />
    </form>
</div>

@model ShowResultViewModel;
@{
    ViewData["Title"] = "Show Result";
}

<div style="display:flex;justify-content:center">
    <table name="ScanResult" class="table-bordered" style="width:40%;" align="center">
        <thead>
            <tr>
                <td colspan="2">Scan Result</td>
            </tr>
        </thead>
        <tbody>
            @if (Model.DataMessages != null && Model.DataMessages.Length >= 0)
            {
                <tr>
                    <td colspan="2" align="left">
                        Number of valid barcodes:&nbsp;&nbsp;@Model.DataMessages.Length
                    </td>
                </tr>
                @for (var i = 0; i < Model.DataMessages.Length; i++)
                {
                    var idx = i + 1;
                    var msg = Model.DataMessages[i];
                    <tr>
                        <td style="width:10%;">@idx:</td>
                        <td align="left">'@msg'</td>
                    </tr>
                }
            }
        </tbody>
    </table>
</div>
<br /><br /><br />
<a asp-action="Index">Back to Index</a>

using Microsoft.AspNetCore.Mvc;
using OnBarcodeReaderASPNETCoreMVCDemo.Models;
using System.Diagnostics;
using OnBarcode.Barcode.BarcodeScanner;

namespace OnBarcodeReaderASPNETCoreMVCDemo.Controllers
{
    public class HomeController : Controller
    {
        private readonly ILogger<HomeController> _logger;

        public HomeController(ILogger<HomeController> logger)
        {
            _logger = logger;
        }

        public IActionResult Index()
        {
            IndexViewModel model = new IndexViewModel();
            //  Set default barcode type to Code 128
            model.SelectedTypeIndex = 5;
            return View(model);
        }

        [HttpPost]
        public async Task<IActionResult> ShowResult(IndexViewModel model)
        {
            String[] result = new String[0];
            if (ModelState.IsValid)
            {
                try
                {
                    if (model.FormFile != null && model.FormFile.Length > 0)
                    {
                        using (MemoryStream stream = new MemoryStream())
                        {
                            await model.FormFile.CopyToAsync(stream);

                            //  Get enum BarcodeType from ComboBox selected index.
                            BarcodeType barcodeType = (BarcodeType)model.SelectedTypeIndex;

                            result = BarcodeScanner.Scan(stream, barcodeType);
                        }
                    }
                    else
                        throw new Exception("No Upload File.");
                }
                catch (Exception)
                {
                    result = new String[0];
                }
            }

            ShowResultViewModel showViewModel = new ShowResultViewModel();
            showViewModel.DataMessages = result;
            return View(showViewModel);
        }

        public IActionResult Privacy()
        {
            return View();
        }

        [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error()
        {
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }
    }
}