Lyo.QRCode 1.0.9

Lyo.QRCode

QR code generation and reading for Lyo: IQRCodeService, QRCodeBuilder, ISO Model 2 encoding in-box (BuiltInQRCodeService), optional QRCoder adapter package Lyo.QRCode.QRCoder, and typed payload helpers (Lyo.QRCode.Payloads) for Wi-Fi, URLs, vCard, mailto:, etc.

Examples

Quick start (built-in encoder)

using Lyo.QRCode;
using Lyo.QRCode.Models;
using Microsoft.Extensions.DependencyInjection;

var services = new ServiceCollection();
services.AddQRCodeService(o => {
    o.DefaultSize = 16; // pixels per module, not total width
    o.DefaultFormat = QRCodeFormat.Png;
    o.DefaultErrorCorrectionLevel = QRCodeErrorCorrectionLevel.Medium;
});

var qr = services.BuildServiceProvider().GetRequiredService<IQRCodeService>();
var result = await qr.GenerateAsync("https://example.com");

if (result.IsSuccess && result is QRCodeResult r && r.ImageBytes != null)
    await File.WriteAllBytesAsync("qr.png", r.ImageBytes);

Typed payload (Wi‑Fi example)

using Lyo.QRCode;
using Lyo.QRCode.Payloads;

var payload = new WifiQrPayload("MySSID", "secret", QrWifiSecurityType.Wpa);
var (_, opts) = QRCodeBuilder.New()
    .WithPayload(payload)
    .WithFormat(QRCodeFormat.Png)
    .WithSize(12)
    .Build();

Architecture

Optional: QRCoder package

Add a project/package reference to Lyo.QRCode.QRCoder and call AddQRCoderQrCodeService (or AddQRCoderQrCodeServiceFromConfiguration) instead of or in addition to AddQRCodeService, depending on how you register IQRCodeService.

Payload helpers (Lyo.QRCode.Payloads)

• Wi-Fi (WifiQrPayload). Omits H: when the SSID is not hidden (better phone compatibility than H:false). Open networks omit P (not P:;).
• SMS (SmsPayload). Defaults to sms: URI scheme. smsto: is opt-in (some Android SMS apps crash on long smsto: bodies). Very long URIs throw (MaxSmsQrUriLength) to avoid app crashes.

Key options

• QRCodeOptions.Size. Pixels per module (each black/white square), not the image width. Total size ≈ module count per side × Size. Decoration applied later may grow that further.
• QRCodeOptions.Icon. Hint only for the encoder. The only field consumed is IconSizePercent, which bumps the effective ECC level so a planned center logo doesn't break scanning. IconBytes, IconFilePath, and DrawIconBorder are metadata for the consumer's overlay call. The QR encoder never composites the icon. Apply the overlay (and any frame/caption/padding) after generation through Lyo.Images.IImageDecorationService (see migration note below).

Migration: decoration moved out of the encoder

QRCodeOptions.Frame, QRCodeBuilder.WithFrame(...), and the optional IImageService / IQrFrameLayoutService constructor parameters on BuiltInQRCodeService are gone. Compose icons and chrome on the returned bytes with Lyo.Images:

using Lyo.Images;
using Lyo.Images.Builders;
using Lyo.Common.Enums;

var qr = await qrService.GenerateAsync(data, options);
var qrBytes = ((QRCodeResult)qr).ImageBytes!;

var decorated = await decoration.Pipeline(qrBytes)
    .Overlay(logoBytes, b => b.WithOverlaySizePercent(18).WithPadColor("#FFFFFF").WithBorder("#000000"))
    .AddCaption(b => b.WithText("Scan Me").WithNotch())
    .AddOuterPadding(b => b.WithPanelColor("#FFFFFF").WithCornerRadius(16))
    .AddFrame(b => b.WithStrokeColor("#1e293b").WithStrokeWidth(2).WithCornerRadius(16))
    .ToByteArrayAsync(ImageFormat.Png);

OverlayAsync works on PNG (raster) and SVG (embeds a base64 PNG <image> before </svg>); the other primitives require raster input.

Error correction

QRCodeErrorCorrectionLevel: Low (~7%), Medium (~15%), Quartile (~25%), High (~30%) recovery. Higher levels tolerate damage and logos better but increase symbol version for the same payload.

Blazor UI (optional)

• Lyo.QRCode.Web.Components. QrCodeWorkbench and related MudBlazor components.

Dependencies

Generated from ProjectReference / PackageReference (same model as docs/Lyo.ProjectGraph.html).

• Lyo.Common (direct, lyo)
• Lyo.Exceptions (direct, lyo)
• Lyo.Metrics (direct, lyo)
• Lyo.Result (direct, lyo)
• Microsoft.Extensions.Configuration.Binder 10.0.5 (direct, microsoft)
• Microsoft.Extensions.DependencyInjection.Abstractions 10.0.5 (direct, microsoft)
• Microsoft.Extensions.Logging.Abstractions 10.0.5 (direct, microsoft)
• SixLabors.ImageSharp 3.1.12 (direct, third-party)
• ZXing.Net 0.16.11 (direct, third-party)
• ZXing.Net.Bindings.ImageSharp.V3 0.16.18 (direct, third-party)
• Microsoft.Extensions.Options.ConfigurationExtensions 10.0.5 (transitive, microsoft)
• System.Memory 4.6.3 (transitive, microsoft, netstandard2.0)
• System.Text.Json 10.0.5 (transitive, microsoft, netstandard2.0)