QRCoder Documentation

You can generate QR codes using two primary patterns:

1. Using a renderer's static helper method (for simple tasks like PNG generation).
2. Creating QRCodeData first, then passing it to a specific renderer (for more control or different formats).

Note: QRCodeGenerator.ECCLevel defines the error correction level (e.g., Q).

using QRCoder;

// Generate a simple black and white PNG QR code
byte[] qrCodeImage = PngByteQRCodeHelper.GetQRCode("Hello World", QRCodeGenerator.ECCLevel.Q, 20);

// Generate a scalable black and white SVG QR code
using var qrCodeData = QRCodeGenerator.GenerateQrCode("Hello World", QRCodeGenerator.ECCLevel.Q);
using var svgRenderer = new SvgQRCode(qrCodeData);
string svg = svgRenderer.GetGraphic();

To use QRCoder in your C# project, install it using the NuGet Package Manager.

PM> Install-Package QRCoder

QRCoder.Xaml is an extension for the QRCoder.NET library that provides the XamlQRCode renderer. It allows you to generate QR codes as DrawingImage objects, which are suitable for use in WPF or other XAML-based projects.

To use it, you must first generate QRCodeData using a QRCodeGenerator, then pass that data to a XamlQRCode instance to retrieve the graphic.

using (QRCodeGenerator qrGenerator = new QRCodeGenerator())
using (QRCodeData qrCodeData = qrGenerator.CreateQrCode("The text which should be encoded.", eccLevel))
using (XamlQRCode qrCode = new XamlQRCode(qrCodeData))
{
    DrawingImage qrCodeAsXaml = qrCode.GetGraphic(20);
}

To generate a scalable SVG, first generate the QRCodeData using QRCodeGenerator.GenerateQrCode, then pass that data to an SvgQRCode renderer and call GetGraphic().

// Generate a scalable black and white SVG QR code
using var qrCodeData = QRCodeGenerator.GenerateQrCode("Hello World", QRCodeGenerator.ECCLevel.Q);
using var svgRenderer = new SvgQRCode(qrCodeData);
string svg = svgRenderer.GetGraphic();

Use PngByteQRCodeHelper.GetQRCode to quickly generate a PNG byte array for a QR code. You must specify the payload string, the Error Correction Code (ECC) level, and the pixel size.

// Generate a simple black and white PNG QR code
byte[] qrCodeImage = PngByteQRCodeHelper.GetQRCode("Hello World", QRCodeGenerator.ECCLevel.Q, 20);

The QRCode and ArtQRCode renderers depend on System.Drawing.Common, which is only supported on Windows in .NET 6+. If you encounter CA1416, System.TypeInitializationException (Gdip), or System.PlatformNotSupportedException, use one of these solutions:

1. Use Windows-specific TFMs: Set <TargetFramework>net8.0-windows</TargetFramework> in your project file.
2. Use Attributes: Mark methods with [SupportedOSPlatform("windows")].
3. Use Platform Guards: Wrap code with #if WINDOWS or if (OperatingSystem.IsWindows()).
4. Use Cross-Platform Renderers: Switch to PngByteQRCode, SvgQRCode, or BitmapByteQRCode to avoid System.Drawing.Common entirely.

ISO-8859-2 encoding is not natively supported in .NET Core and .NET 5+. To use it, you must install the System.Text.Encoding.CodePages NuGet package and register the provider at application startup:

using System.Text;

// Register the code pages encoding provider
Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);

Note: The RussiaPaymentOrder payload generator handles this registration internally.

Instead of manually formatting strings for WiFi, URLs, or contact info, use PayloadGenerator classes to create properly formatted payloads. These payloads can then be passed directly into QRCodeGenerator.GenerateQrCode().

Example: Creating a Bookmark Payload

using QRCoder;

// Create a bookmark payload
var bookmarkPayload = new PayloadGenerator.Bookmark("https://github.com/Shane32/QRCoder", "QRCoder Repository");

// Generate the QR code data from the payload
using var qrCodeData = QRCodeGenerator.GenerateQrCode(bookmarkPayload);

// Or override the ECC level
using var qrCodeData2 = QRCodeGenerator.GenerateQrCode(bookmarkPayload, QRCodeGenerator.ECCLevel.H);

// Render the QR code
using var pngRenderer = new PngByteQRCode(qrCodeData);
byte[] qrCodeImage = pngRenderer.GetGraphic(20);

QRCoder supports Micro QR codes, which are smaller versions of standard QR codes. They have limited storage capacity (e.g., M1 supports as few as 5 numeric digits, M4 up to 35).

To generate a Micro QR code, use QRCodeGenerator.GenerateMicroQrCode. The requestedVersion parameter uses integers from -1 to -4 to represent versions M1 through M4 respectively.

Version and ECC Support:

• M1 (-1): Detection only (no ECC).
• M2 (-2) & M3 (-3): Support ECCLevel.L and ECCLevel.M.
• M4 (-4): Supports ECCLevel.L, ECCLevel.M, and ECCLevel.Q.

using QRCoder;

// Generate a Micro QR code (versions M1-M4, represented as -1 to -4)
using var qrCodeData = QRCodeGenerator.GenerateMicroQrCode("Hello", QRCodeGenerator.ECCLevel.L, requestedVersion: -2);
using var qrCode = new PngByteQRCode(qrCodeData);
byte[] qrCodeImage = qrCode.GetGraphic(20);