Recognize barcodes in image in ASP.NET Core application

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This tutorial shows how to create a blank ASP.NET Core Web application in Visual Studio .NET 2022 and recognize barcodes in image in ASP.NET Core application.

Here are steps, which must be done:

Create a blank ASP.NET Core Web application.
Open Visual Studio .NET 2022 and create a new project, of ASP.NET Core Web application type:

Configure the project to use .NET 8.0:
Server side: Add references to the Vintasoft assemblies to ASP.NET Core Web application.
Add references to the Vintasoft.Barcode.dll, Vintasoft.Barcode.SkiaSharp.dll, Vintasoft.Shared.dll, Vintasoft.Shared.Web.dll, Vintasoft.Barcode.Web.Services.dll and Vintasoft.Barcode.AspNetCore.ApiControllers.dll assemblies from "<InstallPath>\VintaSoft Barcode .NET 15.1\Bin\DotNet8\AnyCPU\" folder in ASP.NET Core Web application.
Server side: Add Web API controller that allows to recognizes barcodes in image.
- Add the "Controllers" folder to the project.
- Press the right mouse button on the "Controllers" folder and select the "Add => Controller..." menu from context menu
- Select Empty API controller template, set the controller name to the "MyVintasoftBarcodeApiController" and press the "Add" button
- Specify that MyVintasoftBarcodeApiController class is derived from Vintasoft.Barcode.AspNetCore.ApiControllers.VintasoftBarcodeApiController class
  
  Here are source codes of MyVintasoftBarcodeApiController class:
  - C#
  using Microsoft.AspNetCore.Hosting; using Microsoft.AspNetCore.Mvc; using Vintasoft.Barcode.AspNetCore.ApiControllers; namespace WebApplication1.Controllers { public class MyVintasoftBarcodeApiController : VintasoftBarcodeApiController { public MyVintasoftBarcodeApiController(IWebHostEnvironment hostingEnvironment) : base(hostingEnvironment) { } } }
Server side: Add Newtonsoft JSON for deserialization of barcode recognition results.
- Add reference to the Microsoft.AspNetCore.Mvc.NewtonsoftJson nuget-package:
Server side: Create MVC controller for web view that will display barcode recognition result.
- Press the right mouse button on the "Controllers" folder and select the "Add => Controller..." menu from context menu
- Select "MVC Controller - Empty" template, set the controller name to the "HomeController" and press the "Add" button
- Open "Program.cs" file, add controllers with views and Newtonsoft.Json formatters to the services of ASP.NET Core application:
  
  Add created MVC controller to the endpoints of ASP.NET Core application:
  
  Here are C# source codes of Program.cs file:
  - C#
  var builder = WebApplication.CreateBuilder(args); // Add services to the container. builder.Services.AddRazorPages(); builder.Services.AddControllersWithViews().AddNewtonsoftJson(); var app = builder.Build(); app.UseHttpsRedirection(); app.UseStaticFiles(); app.UseRouting(); app.UseEndpoints(endpoints => { endpoints.MapControllerRoute("default", "{controller=Home}/{action=Index}/{id?}"); }); app.MapRazorPages(); app.Run();
Client side: Create web view for displaying barcode recognition result.
- Open "HomeController.cs" file, press the right mouse button on the "Index" method of HomeController class and select the "Add View..." menu from context menu
- Select "Razor View - Empty" template, press the "Add" button, Set view name to "Index" and press the "Add" button => "Views\Home\Index.cshtml" file will be created
Client side: Add Vintasoft JavaScript files to the project.
- Add the "wwwroot\Scripts\" folder to ASP.NET Core application.
- Copy Vintasoft.Shared.js and Vintasoft.Barcode.js files from "<InstallPath>\VintaSoft Barcode .NET 15.1\Bin\JavaScript\" folder into "wwwroot\Scripts\" folder.

Client side: Add JavaScript code, which recognizes barcode in image and displays barcode recognition result, to the web view.

Create folder "wwwroot\UploadedImageFiles\SessionID" and copy image file with barcodes "<InstallPath>VintaSoft\Barcode .NET 15.1\Images\AllSupportedBarcodes.png" to the folder. We will recognize barcodes in this image.
Open web view - file "Views\Home\Index.cshtml".

Add base code:

Here is base HTML code:

HTML

@{
    Layout = null;
}

<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>ASP.NET Core Barcode Generator Demo</title>

</head>
<body>

</body>
</html>

Add references to Vintasoft JavaScript files:

Here is HTML code that adds references to Vintasoft JavaScript files:

HTML

<script src="~/Scripts/Vintasoft.Shared.js" type="text/javascript"></script>
<script src="~/Scripts/Vintasoft.Barcode.js" type="text/javascript"></script>

Add HTML markup (a div element that will display barcode recogntion result) to the web view:

Here is HTML markup code:
- HTML
```
<div id="barcodeInformation"></div>
```

Add JavaScript code that recognizes barcode in image and displays barcode recognition result:

Here is JavaScript code that recognizes barcode in image and displays barcode recognition result:

JavaScript

<script type="text/javascript">

    /**
     * Barcodes are recognized successfully.
     */
    function __readBarcodes_success(data) {
        if (data.success) {
            // get the barcode recognition result
            var barcodeRecognitionResults = data.results;

            var htmlMarkup = '';
            // if no barcodes found
            if (barcodeRecognitionResults.length == 0) {
                htmlMarkup = 'No barcodes found.';
            }
            // if barcodes are found
            else {
                htmlMarkup = barcodeRecognitionResults.length.toString() + ' barcodes are found.<br />';
                htmlMarkup += '<br />';

                // for each recognized barcode
                for (var i = 0; i < barcodeRecognitionResults.length; i++) {
                    // get the barcode recognition result
                    var barcodeRecognitionResult = barcodeRecognitionResults[i];

                    // output information about recognized barcode
                    htmlMarkup += '[' + (i + 1) + ':' + barcodeRecognitionResult.barcodeType + ']<br />';
                    htmlMarkup += '  Value: ' + barcodeRecognitionResult.value + '<br />';
                    htmlMarkup += '  Confidence: ' + barcodeRecognitionResult.confidence + '<br />';
                    htmlMarkup += '  Reading quality: ' + barcodeRecognitionResult.readingQuality.toFixed(2) + '<br />';
                    htmlMarkup += '  Threshold: ' + barcodeRecognitionResult.threshold + '<br />';
                    htmlMarkup += '  Region: ' +
                        'LT=(' + barcodeRecognitionResult.region.leftTop.x + ',' + barcodeRecognitionResult.region.leftTop.y + '); ' +
                        'RT=(' + barcodeRecognitionResult.region.rightTop.x + ',' + barcodeRecognitionResult.region.rightTop.y + '); ' +
                        'LB=(' + barcodeRecognitionResult.region.leftBottom.x + ',' + barcodeRecognitionResult.region.leftBottom.y + '); ' +
                        'RB=(' + barcodeRecognitionResult.region.rightBottom.x + ',' + barcodeRecognitionResult.region.rightBottom.y + '); ' +
                        'Angle=' + barcodeRecognitionResult.region.angle.toFixed(1) + '°<br />';

                    htmlMarkup += '<br />';
                }
            }

            var barcodeInformationElement = document.getElementById("barcodeInformation");
            barcodeInformationElement.innerHTML = htmlMarkup;
        }
    }

    /**
     * Barcode recognition is failed.
     */
    function __readBarcodes_fail(data) {
        // show information about error
        alert(data.errorMessage);
    }


    // set the session identifier
    Vintasoft.Shared.WebImagingEnviromentJS.set_SessionId("SessionID");

    // create service that allows to recognize barcodes
    var barcodeService = new Vintasoft.Shared.WebServiceControllerJS("vintasoft/api/MyVintasoftBarcodeApi");

    // create the barcode reader
    var barcodeReader = new Vintasoft.Barcode.WebBarcodeReaderJS(barcodeService);
    // specify that Code39 barcode must be searched
    barcodeReader.get_Settings().set_BarcodeType(new Vintasoft.Barcode.WebBarcodeTypeEnumJS("Code39"));

    // create web image that references to a file "AllSupportedBarcodes.png" in directory "/UploadedImageFiles/SessionID/"
    var imageSource = new Vintasoft.Shared.WebImageSourceJS("AllSupportedBarcodes.png");
    var image = new Vintasoft.Shared.WebImageJS(imageSource, 0);

    // send an asynchronous request for barcode recognition
    barcodeReader.readBarcodes(image, this.__readBarcodes_success, this.__readBarcodes_fail);
</script>

Delete "Pages" folder.

Run the ASP.NET Core application and see the result.

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Create a blank ASP.NET Core Web application.

Server side: Add references to the Vintasoft assemblies to ASP.NET Core Web application.

Server side: Add Web API controller that allows to recognizes barcodes in image.

Server side: Add Newtonsoft JSON for deserialization of barcode recognition results.

Server side: Create MVC controller for web view that will display barcode recognition result.

Client side: Create web view for displaying barcode recognition result.

Client side: Add Vintasoft JavaScript files to the project.

Client side: Add JavaScript code, which recognizes barcode in image and displays barcode recognition result, to the web view.

Run the ASP.NET Core application and see the result.