Introduction
In this article, we will explain how to create a QR Code Generator in ASP.NET Core 1.0, using Zxing.Net.
Background
I tried to create a QR Code Generator in ASP.NET Core, using third party libraries but in most of the cases codes are not fully supported in ASP.NET Core because of some version issues etc. I searched a lot in Google but finally I found “Zxing.Net” and it is a library, which supports decoding and generating of the barcodes. I had a discussion with MicJahn and came up with a great solution.
Before reading this article, you must read the articles given below for ASP.NET Core knowledge.
- GETTING STARTED WITH ASP.NET CORE 1.0
- PROJECT LAYOUT IN ASP.NET CORE 1.0
- MIDDLEWARE AND STATICFILES IN ASP.NET CORE 1.0 – PART 1
- MIDDLEWARE AND STATICFILES IN ASP.NET CORE 1.0 – PART 2
Zxing.Net
A library, which supports decoding and generating of the barcodes (Example: QR Code, PDF 417, EAN, UPC, Aztec, Data Matrix, Codabar) within the images.
Assemblies Required
The assemblies given below are required for QR Code Generator.
using Microsoft.AspNetCore.Razor.TagHelpers; using System; using System.IO; using ZXing.QrCode;
Packages required
We need the packages given below for drawing and creating QR Code Generator.
"CoreCompat.System.Drawing": "1.0.0-beta006", "ZXing.Net": "0.15.0"
C#
QRCodeTagHelper class given below contains QR Code Generator methods etc.
namespace QRCodeApp {
[HtmlTargetElement("qrcode")]
public class QRCodeTagHelper: TagHelper {
public override void Process(TagHelperContext context, TagHelperOutput output) {
var QrcodeContent = context.AllAttributes["content"].Value.ToString();
var alt = context.AllAttributes["alt"].Value.ToString();
var width = 250; // width of the Qr Code
var height = 250; // height of the Qr Code
var margin = 0;
var qrCodeWriter = new ZXing.BarcodeWriterPixelData {
Format = ZXing.BarcodeFormat.QR_CODE,
Options = new QrCodeEncodingOptions {
Height = height, Width = width, Margin = margin
}
};
var pixelData = qrCodeWriter.Write(QrcodeContent);
// creating a bitmap from the raw pixel data; if only black and white colors are used it makes no difference
// that the pixel data ist BGRA oriented and the bitmap is initialized with RGB
using(var bitmap = new System.Drawing.Bitmap(pixelData.Width, pixelData.Height, System.Drawing.Imaging.PixelFormat.Format32bppRgb))
using(var ms = new MemoryStream()) {
var bitmapData = bitmap.LockBits(new System.Drawing.Rectangle(0, 0, pixelData.Width, pixelData.Height), System.Drawing.Imaging.ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format32bppRgb);
try {
// we assume that the row stride of the bitmap is aligned to 4 byte multiplied by the width of the image
System.Runtime.InteropServices.Marshal.Copy(pixelData.Pixels, 0, bitmapData.Scan0, pixelData.Pixels.Length);
} finally {
bitmap.UnlockBits(bitmapData);
}
// save to stream as PNG
bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
output.TagName = "img";
output.Attributes.Clear();
output.Attributes.Add("width", width);
output.Attributes.Add("height", height);
output.Attributes.Add("alt", alt);
output.Attributes.Add("src", String.Format("data:image/png;base64,{0}", Convert.ToBase64String(ms.ToArray())));
}
}
}
}
Index.chtml
The code given below will display QR Code Generator.
@{
ViewData["Title"] = "Home";
}
<h2>@ViewData["Title"].</h2>
<h3>@ViewData["Message"]</h3>
A library which supports decoding and generating of barcodes (like QR Code, PDF 417, EAN, UPC, Aztec, Data Matrix, Codabar) within images.
<qrcode alt="QR Code" content="https://rajeeshmenoth.wordpress.com/" />
https://rajeeshmenoth.wordpress.com/
_ViewImports.cshtml
The code Injecting TagHelper given below is in the entire Application.
@addTagHelper "*, QRCodeApp"
project.json
The dependencies given below are required to create QR Code Application.
{
"dependencies": {
"Microsoft.AspNetCore.Diagnostics": "1.0.0",
"Microsoft.AspNetCore.Mvc": "1.1.2",
"Microsoft.AspNetCore.Mvc.Core": "1.1.2",
"Microsoft.AspNetCore.Server.IISIntegration": "1.0.0",
"Microsoft.AspNetCore.Server.Kestrel": "1.0.1",
"Microsoft.AspNetCore.StaticFiles": "1.1.1",
"Microsoft.Extensions.Logging.Console": "1.0.0",
"CoreCompat.System.Drawing": "1.0.0-beta006",
"ZXing.Net": "0.15.0"
},
"tools": {
"Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final"
},
"frameworks": {
"net452": { }
},
"buildOptions": {
"emitEntryPoint": true,
"preserveCompilationContext": true
},
"publishOptions": {
"include": [
"wwwroot",
"web.config"
]
},
"scripts": {
"postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
}
}
Output
QRCode Generator
Reference
See Also
You can download other ASP.NET Core 1.0 source codes from MSDN Code, using the links, mentioned below.
- Middleware And Staticfiles In ASP.NET Core 1.0 – Part One
- Middleware And Staticfiles In ASP.NET Core 1.0 – Part Two
- Create An Aurelia Single Page Application In ASP.NET Core 1.0
- Create Rest API Or Web API With ASP.NET Core 1.0
- Adding A Configuration Source File In ASP.NET Core 1.0
- Code First Migration – ASP.NET Core MVC With EntityFrameWork Core
- Send Email Using ASP.NET CORE 1.1 With MailKit In VisualStudio 2017
Conclusion
We learnt how to create a QR Code Generator in ASP.NET Core 1.0 Using Zxing.Net. I hope, you liked this article. Please share your valuable suggestions and feedback.
Rajeesh Menoth 