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Generate 2d barcode QR Code images in Visual C# .NET with complete sample C# source code
In this C# ASP.NET tutorial page, you will learn how to generate QR Code barcode images in ASP.NET Core MVC (Model-View-Controller) web application using C# code.
How to create QR Code barcodes in ASP.NET Core MVC using C#
Prerequisites Top
Download and install the following software on your computer
Create a new ASP.NET Core MVC web app with QR Code generation on web page using C#TopStep 1: Create a new ASP.NET Core MVC web app
Step 2: Install SkiaSharp
Step 3: Install OnBarcode QR Code Generator DLL
Step 4.1: Add C# source code to Controller
Copy all following codes to replace the content of the file HomeController.cs
using Microsoft.AspNetCore.Mvc; using OnBarcode.QRCodeGenerator.ASPNETCoreMVCDemo.Models; using System.Diagnostics; namespace OnBarcode.QRCodeGenerator.ASPNETCoreMVCDemo.Controllers { public class HomeController : Controller { // Cannot be empty. private static String tbMessage = "QRCode"; // Must be a positive float value less than 10. private static String tbWidth = "2"; // Must be a positive int value less than 1200. private static String tbResolution = "300"; // Hex String: from 0 to FFFFFF private static String tbForeColor = "000000"; // Hex String: from 0 to FFFFFF private static String tbBackColor = "FFFFFF"; private readonly ILogger<HomeController> _logger; public HomeController(ILogger<HomeController> logger) { _logger = logger; } public IActionResult Index() { // Set default value to text box. ViewData["Message"] = tbMessage; ViewData["Width"] = tbWidth; ViewData["Resolution"] = tbResolution; ViewData["ForeColor"] = tbForeColor; ViewData["BackColor"] = tbBackColor; return View(); } 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 }); } // public Task<IActionResult> Show() { try { // Update backup tbMessage = Request.Form["tbMessage"].ToString(); tbWidth = Request.Form["tbWidth"].ToString(); tbResolution = Request.Form["tbResolution"].ToString(); tbForeColor = Request.Form["tbForeColor"].ToString(); tbBackColor = Request.Form["tbBackColor"].ToString(); byte[] dataBytes = tryToCreateBarcode(); if (dataBytes == null || dataBytes.Length == 0) throw new Exception("fail to create barcode"); ViewData["BarcodeImage"] = System.Convert.ToBase64String(dataBytes); ViewData["ViewResult"] = "SUCCESS"; return Task.FromResult<IActionResult>(View()); } catch (Exception) { //return Task.FromResult<IActionResult>(RedirectToAction(nameof(Index))); ViewData["ViewResult"] = "FAILED"; return Task.FromResult<IActionResult>(View()); } } // Create barcode. Return empty array if failed. private byte[] tryToCreateBarcode() { try { if (String.IsNullOrEmpty(tbMessage)) throw new Exception("Message cannot be null or empty."); int resolution = Convert.ToInt32(tbResolution); if (resolution > 1200) throw new Exception("Resolution out of range."); float width = Convert.ToSingle(tbWidth); if (width > 10F) throw new Exception("Width out of range."); // Hex String: RRGGBB uint rgbForeColor = Convert.ToUInt32(tbForeColor, 16) & 0xFFFFFF; // Hex String: RRGGBB uint rgbBackColor = Convert.ToUInt32(tbBackColor, 16) & 0xFFFFFF; OnBarcode.Barcode.QRCode qrcode = new OnBarcode.Barcode.QRCode(); qrcode.DataMode = Barcode.QRCodeDataMode.Auto; qrcode.Data = tbMessage; qrcode.UOM = Barcode.UnitOfMeasure.INCH; qrcode.Resolution = resolution; qrcode.BarcodeWidth = width; qrcode.BarcodeHeight = width; qrcode.ForeColor = new SkiaSharp.SKColor(0xFF000000 + rgbForeColor); qrcode.BackColor = new SkiaSharp.SKColor(0xFF000000 + rgbBackColor); qrcode.AutoResize = true; qrcode.ImageFormat = SkiaSharp.SKEncodedImageFormat.Png; return qrcode.drawBarcodeAsBytes(); } catch (Exception) { return new byte[0]; } } } } Step 4.2: Add C# source code to Views
Copy all following codes to replace the content of the file Index.cshtml
@{
ViewData["Title"] = "Home Page";
}
<div class="text-center">
<br />
<form asp-action="Show">
<table align="center">
<tbody>
<tr>
<td align="right">Data Message: </td>
<td>
<input type="text" id="tb1" name="tbMessage" style="width: 300px; " asp-for=@ViewData["Message"] />
</td>
</tr>
<tr>
<td align="right">Width (inch): </td>
<td>
<input type="text" id="tb2" name="tbWidth" style="width: 300px; " asp-for=@ViewData["Width"] />
</td>
</tr>
<tr>
<td align="right">Resolution (dpi): </td>
<td>
<input type="text" id="tb3" name="tbResolution" style="width: 300px; " asp-for=@ViewData["Resolution"] />
</td>
</tr>
<tr>
<td align="right">Fore Color: </td>
<td>
<input type="text" id="tb4" name="tbForeColor" style="width: 300px; " asp-for=@ViewData["ForeColor"] />
</td>
</tr>
<tr>
<td align="right">Back Color: </td>
<td>
<input type="text" id="tb5" name="tbBackColor" style="width: 300px; " asp-for=@ViewData["BackColor"] />
</td>
</tr>
</tbody>
</table>
<br />
<input type="submit" value="Show" />
<br />
<br />
</form>
</div>
Add a new View Show.cshtml to display the generated QR Code image in browser.
Contents of Show.cshtml @{
ViewData["Title"] = "Show";
}
<h1>Show Barcode - @ViewData["ViewResult"]</h1>
<div style="display:flex;justify-content:center">
<a asp-action="Index">Back to Index</a>
</div>
<br />
<div style="display:flex;justify-content:center">
<img src="data:image/png;base64,@ViewData["BarcodeImage"]" />
</div>
Step 5: Run the web appIt is done. Now press "Ctrl+F5" to run the project.
You will view the app running in the browser. Click button Show to generate QR Code barcode image. 
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