how to create qr code in razor page

Daniel Parker

3 min read

·

16-01-2025

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This article will guide you through generating QR codes dynamically within your Razor Pages applications. We'll leverage a popular NuGet package and show you how to seamlessly integrate QR code generation into your pages. This allows for creating personalized, on-the-fly QR codes without needing external services.

Setting Up Your Project

Before we begin, ensure you have a Razor Pages project set up. If you don't already have one, create a new project in Visual Studio using the "ASP.NET Core Web App" template and selecting the Razor Pages option.

Next, we need to install the necessary NuGet package. This package simplifies the process of creating QR codes:

1. Install the QRCode.Generator package: In the NuGet Package Manager Console, run the command: Install-Package QRCode.Generator

Generating the QR Code in your Razor Page

Now, let's add the code to generate the QR code within your Razor Page. This example assumes you have a Razor Page called Index.cshtml.

@page
@model IndexModel

@{
    // Generate QR code data
    var qrCodeData = "https://www.example.com"; // Replace with your desired data

    // Create a QR code generator instance
    var qrGenerator = QRCodeGenerator.CreateQrCode(qrCodeData, QRCodeGenerator.ECCLevel.Q); // ECCLevel.Q for high error correction

    // Get the QR code as a byte array (PNG format)
    var qrCodeAsPng = qrGenerator.GetGraphic(20, Color.Black, Color.White, true); // 20 is the size in pixels

    // Convert the byte array to base64 string for embedding in the img tag
    var base64QrCode = Convert.ToBase64String(qrCodeAsPng);

}

<img src="data:image/png;base64,@base64QrCode" alt="QR Code" /> 

This code snippet does the following:

1. Defines QR Code Data: qrCodeData holds the data to be encoded in the QR code (URL, text, etc.). Replace "https://www.example.com" with your actual data.

2. Creates QR Code: QRCodeGenerator.CreateQrCode() generates the QR code with error correction level Q (high reliability). You can adjust the ECCLevel if needed. Other levels include L, M, and H.

3. Gets PNG Image: GetGraphic() converts the QR code data into a PNG image. Adjust the 20 (pixel size) to control the image dimensions. Color.Black and Color.White set the foreground and background colors, respectively. true enables a quiet zone around the QR code.

4. Base64 Encoding: The PNG image is converted to a Base64 string for embedding directly into the HTML <img> tag.

5. Displays QR Code: The <img> tag displays the Base64 encoded QR code on the page.

Customizing Your QR Code

You can customize the appearance of your QR code by adjusting parameters in the GetGraphic() method:

• Size: Change the first parameter in GetGraphic(20, ...) to adjust the size of the QR code.
• Colors: Modify Color.Black and Color.White to use different foreground and background colors.
• Quiet Zone: The boolean value in GetGraphic(..., ..., true) controls the presence of a quiet zone. A quiet zone improves scannability.
• Error Correction Level: Adjust the ECCLevel in QRCodeGenerator.CreateQrCode() to balance size and error correction capability.

Handling Different Data Types

This example shows encoding a URL. You can encode other data types (text, numbers) by simply changing the qrCodeData variable. Ensure the data is properly formatted for QR code encoding. For complex data, consider using a suitable encoding scheme.

Conclusion

Generating QR codes dynamically in your Razor Pages is straightforward using the QRCode.Generator NuGet package. This technique allows for creating personalized, context-aware QR codes within your application, enhancing user interaction and functionality. Remember to adjust the parameters to optimize the QR code's size, appearance, and error correction level according to your needs.