How to Generate QR Code in Blazor

QR stands for "Quick Response". It is a 2D barcode that can store website addresses, text, phone numbers, email addresses, and much more. It is widely used in mobile marketing, with extensive use of smartphones. QR code provides users instant access to the information hidden behind the code. A QR code generator is a tool that allows you to generate different QR barcode types. QR code is similar to a barcode but stores much more information and characters in any language.

Blazor is an ASP.NET web framework for creating interactive web apps using C# and HTML. UIs are created using Blazor instead of JavaScript. Generating QR codes in web applications has become necessary as it helps people easily connect to multiple digital platforms. QR code is easy to scan and also helps you at payment centers. Blazor WebAssembly application, or Blazor server application, allows you to create interactive UI web apps integrating QR code functionalities easily. Here, we will make Blazor QR code generator using the IronBarcode in C#

IronBarcode - C#

IronBarcode is a C# Barcode & QR code Library that allows you to read and generate barcodes and QR codes easily in any .NET C# applications. It prioritizes speed, accuracy, and ease of use for C#

IronBarcode is a user-friendly library that allows developers to easily add, read, and style QR codes in C# projects, usually within minutes. It enables developers to create QR codes in formats like Aztec, Data Matrix, MaxiCode. Different barcode types are available using IronBarcode, e.g., Code 39, Code 128, RSS14, etc.

IronBarcode is compatible with all .NET Framework languages, i.e., C#, F#, and VB.NET. It supports all .NET platforms listed below:

  • .NET 7, 6 & 5
  • .NET Core 2x & 3x
  • .NET Standard 2
  • .NET Framework 4.6.2+

How to Generate QR Code in Blazor Server Application?

Prerequisites

To create QR codes in Blazor web apps in C#, we require the following components:

  1. Visual Studio - It is an Integrated Development Environment (IDE) used for C# development. It can be downloaded from the Visual Studio website. Or you can use any other IDE supported for C#
  2. Blazor Server App: Creating Blazor Server app is the primary task. Follow the given steps below to create a Blazor server web application.

    • Open your IDE or Visual Studio. Click Create a new project.

    How to Generate QR Code in Blazor: Figure 1

    • Choose Blazor Server App from the available project options.

    How to Generate QR Code in Blazor: Figure 2

    • Next, set the location and name your project.

    How to Generate QR Code in Blazor: Figure 3

    • Next, set the additional information for your project. Select an appropriate .NET Framework Version. IronBarcode supports .NET versions 2 through 7, with .NET 7 being the latest.

    How to Generate QR Code in Blazor: Figure 4

  3. IronBarcode - The .NET QR code and Barcode library that helps to generate and read different barcode types. Following are the different ways to install IronBarcode:
  4. Direct download IronBarcode from the NuGet website.
  5. Install via Manage NuGet packages for solution in Visual Studio tools or right-click on solution explorer to choose NuGet Package Manager.
  6. Download IronBarcode DLL directly from the Iron Software website.

Adding IronBarcode Namespace

Once everything is installed and ready, add the following assembly reference to your Blazor barcode application's "Imports.razor" file:

@using IronBarCode
@using IronBarCode
'INSTANT VB TODO TASK: The following line uses invalid syntax:
'@using IronBarCode
VB   C#

How to Generate QR Code in Blazor: Figure 5

Add License Key

IronBarcode must be licensed to be used for deployment. You can get your free trial license key from here. Add the following lines of code to Program.cs file:

using IronBarCode;
License.LicenseKey = "YOUR-KEY-HERE";
using IronBarCode;
License.LicenseKey = "YOUR-KEY-HERE";
Imports IronBarCode
License.LicenseKey = "YOUR-KEY-HERE"
VB   C#

Steps to Generate QR Code

The following steps will help generate QR codes in the best possible way in Blazor Server application:

Adding Blazor HTML Components

First, we are going to add some HTML code to the "Index.razor" page. The code consists of some headings, an input field, and buttons.

Use the code below to add the components to Blazor barcode app:

Welcome to Blazor QR Code Generator
Enter the value to Generate QR Code:

Generate QR Code
Generated QR Code:
Welcome to Blazor QR Code Generator
Enter the value to Generate QR Code:

Generate QR Code
Generated QR Code:
'INSTANT VB TODO TASK: The following line uses invalid syntax:
'Welcome @to Blazor QR Code Generator Enter the value @to Generate QR Code: Generate QR Code Generated QR Code:
VB   C#

The output is as follows:

How to Generate QR Code in Blazor: Figure 6

The text field is used to get input from the user, and the generate button will call the onclick method to create a QR code. The created QR code will be displayed under the "Generated QR Code:" heading. Now, let's create the QRCodeGenerater method.

Create the QrCodeGenerator Method

It's time to use the powerful IronBarcode library in Visual Studio to generate QR codes. The @code section is added to "Index.razor" page. Let's first see the complete code below:

@code {
    private string qrCode = "";
    private string text = "";

    private void QRCodeGenerator()
    {
        GeneratedBarcode myQRCode = QRCodeWriter.CreateQrCode(text);
        qrCode = Convert.ToString(myQRCode.ToHtmlTag());
    }
}
@code {
    private string qrCode = "";
    private string text = "";

    private void QRCodeGenerator()
    {
        GeneratedBarcode myQRCode = QRCodeWriter.CreateQrCode(text);
        qrCode = Convert.ToString(myQRCode.ToHtmlTag());
    }
}
code
If True Then
	private String qrCode = ""
	private String text = ""

'INSTANT VB TODO TASK: Local functions are not converted by Instant VB:
'	private void QRCodeGenerator()
'	{
'		GeneratedBarcode myQRCode = QRCodeWriter.CreateQrCode(text);
'		qrCode = Convert.ToString(myQRCode.ToHtmlTag());
'	}
End If
VB   C#

In the above code, there are two private string variables. qrCode will display the generated QR code, and text will get the user input from the input field. Then, in the QRCodeGenerator method, myQRCode is created using the QRCodeWriter class's CreateQrCode method. The CreateQrCode method provides several parameters to enhance the code output. You can customize the size of the QR code, set error correction code words to maintain the error correction level and change the QrVersion. The code below helps you work with other parameters as well:

QRCodeWriter.CreateQrCode("https://ironsoftware.com/csharp/barcode/", 500, QRCodeWriter.QrErrorCorrectionLevel.High, 0)
QRCodeWriter.CreateQrCode("https://ironsoftware.com/csharp/barcode/", 500, QRCodeWriter.QrErrorCorrectionLevel.High, 0)
'INSTANT VB TODO TASK: The following line uses invalid syntax:
'QRCodeWriter.CreateQrCode("https://ironsoftware.com/csharp/barcode/", 500, QRCodeWriter.QrErrorCorrectionLevel.High, 0)
VB   C#

Finally, the generated Blazor barcode is converted to an HTML tag and then to a qrCode string.

Get more detail on IronBarcode features from this code examples page.

Display on the Blazor Server Application Home Page

Add the code below in HTML components in "Index.razor" page, after H4 heading to display qrCode:

@((MarkupString)qrCode)
@((MarkupString)qrCode)
'INSTANT VB TODO TASK: The following line uses invalid syntax:
'@((MarkupString)qrCode)
VB   C#

Save As a PNG File

You can also save it to a PNG file using the SaveAsPng method:

myQRCode.SaveAsPng("myQRCode.png");
myQRCode.SaveAsPng("myQRCode.png");
myQRCode.SaveAsPng("myQRCode.png")
VB   C#

How to Generate QR Code in Blazor: Figure 7

Generate QR Code on Page Load

You can also create a QR code on page load and display it for the users to scan for data. The following code helps you achieve this task asynchronously:

@((MarkupString)qrCode)

@code {
    private string qrCode = "";
    protected override async Task OnInitializedAsync()
    {
        await Task.Run(() => qrCode = Convert.ToString(QRCodeWriter.CreateQrCode("https://ironsoftware.com/csharp/barcode/", 500, QRCodeWriter.QrErrorCorrectionLevel.High, 0).ToHtmlTag()));
    }
}
@((MarkupString)qrCode)

@code {
    private string qrCode = "";
    protected override async Task OnInitializedAsync()
    {
        await Task.Run(() => qrCode = Convert.ToString(QRCodeWriter.CreateQrCode("https://ironsoftware.com/csharp/barcode/", 500, QRCodeWriter.QrErrorCorrectionLevel.High, 0).ToHtmlTag()));
    }
}
'INSTANT VB WARNING: The following constructor is declared outside of its associated class:
'ORIGINAL LINE: @((MarkupString)qrCode) @code
Private Sub New(ByVal qrCode As (MarkupString))
	private String qrCode = ""
'INSTANT VB TODO TASK: Local functions are not converted by Instant VB:
'	protected override async Task OnInitializedAsync()
'	{
'		await Task.Run(() => qrCode = Convert.ToString(QRCodeWriter.CreateQrCode("https://ironsoftware.com/csharp/barcode/", 500, QRCodeWriter.QrErrorCorrectionLevel.High, 0).ToHtmlTag()));
'	}
End Sub
VB   C#

How to Generate QR Code in Blazor: Figure 8

Summary

In this article, we learned how to generate QR codes in Blazor Server application using IronBarcode in C#. IronBarcode is a flexible library and provides all necessary methods and support for Blazor apps.

IronBarcode easily converts plain text, images, videos, or any other data to QR codes. You can control the code size, error correction levels, and its version. You can use IronBarcode to scan barcodes in Blazor applications. A complete example is here.

IronBarcode is free for development but must be licensed for commercial and deployment purposes. You can try the free trial to test all its functionality.