Creating QR Code In ASP.NET Core

Introduction

Creating a QR code in ASP.NET Core is straightforward using the QRCoder library. This library allows you to generate QR codes easily. Here’s a step-by-step guide along with a code example:

Step 1: Install the QRCoder NuGet Package

In your ASP.NET Core project, open a terminal or package manager console and run the following command to install the QRCoder NuGet package:

dotnet add package QRCoder

Step 2: Generate a QR Code

In your ASP.NET Core controller or service, you can generate a QR code using the QRCoder library. Here’s a basic example:

using Microsoft.AspNetCore.Mvc;
using QRCoder;
using System.Drawing;
using System.IO;

namespace YourNamespace.Controllers
{
    [ApiController]
    [Route("api/[controller]")]
    public class QRCodeController : ControllerBase
    {
        [HttpGet("{data}")]
        public IActionResult Get(string data)
        {
            using var qrGenerator = new QRCodeGenerator();
            using var qrCodeData = qrGenerator.CreateQrCode(data, QRCodeGenerator.ECCLevel.Q);
            using var qrCode = new QRCode(qrCodeData);
            using var qrCodeImage = qrCode.GetGraphic(20); // Size of QR code

            // Convert QR code image to a stream
            using var stream = new MemoryStream();
            qrCodeImage.Save(stream, ImageFormat.Png); // You can use other formats like JPEG

            // Return the QR code image as a file
            return File(stream.ToArray(), "image/png");
        }
    }
}

Step 3: Test the QR Code Generation

Assuming you have your ASP.NET Core application running, you can test the QR code generation by making a GET request to the QRCodeController:

GET /api/QRCode/YourDataHere

Replace YourDataHere with the data you want to encode into the QR code. This could be a URL, text, or any data you want to represent.

The response will be the generated QR code image.

Step 4: Display the QR Code Image

You can display the generated QR code image in an HTML page by including it as an image source:

<img src="/api/QRCode/YourDataHere" alt="QR Code">

This will render the QR code on the webpage.

Remember to adjust the URL path according to your application’s routing configuration.

Please note that this is a basic example. Depending on your requirements, you may need to handle error cases, customize the QR code appearance, and add additional features.