QR Code Scanning with Flutter: A Comprehensive Guide

QR code scanning is a ubiquitous need in today's mobile applications. The QR Code Scanner plugin for Flutter provides a seamless and reliable solution for integrating QR code scanning capabilities into your Flutter apps.

Features

• Native integration for Android and iOS
• Real-time QR code scanning
• Customizable settings (flash, camera flip, pause/resume)
• Support for various barcode formats

Android Integration

1. Update Gradle, Kotlin, and Kotlin Gradle Plugin versions in your android/build.gradle file.
2. Change minSdkVersion to 20 in your android/app/build.gradle file.

iOS Integration

1. Add the following to your Info.plist file:

io.flutter.embedded_views_preview

NSCameraUsageDescription
This app needs camera access to scan QR codes

Usage

1. Create a QRView widget:

import 'package:qr_code_scanner/qr_code_scanner.dart';

final GlobalKey qrKey = GlobalKey(debugLabel: 'QR');
QRViewController? controller;

class QRViewExampleState extends State {
  Barcode? result;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        children: [
          Expanded(
            flex: 5,
            child: QRView(
              key: qrKey,
              onQRViewCreated: _onQRViewCreated,
            ),
          ),
          Expanded(
            flex: 1,
            child: Center(
              child: (result != null)
                  ? Text('Barcode Type: ${result.format}\nData: ${result.code}')
                  : Text('Scan a code'),
            ),
          ),
        ],
      ),
    );
  }

  void _onQRViewCreated(QRViewController controller) {
    this.controller = controller;
    controller.scannedDataStream.listen((scanData) {
      setState(() {
        result = scanData;
      });
    });
  }

  @override
  void dispose() {
    controller?.dispose();
    super.dispose();
  }
}

1. Listen for scanned QR codes:

controller.scannedDataStream.listen((scanData) {
  // Do something with the scanned data
});

Customization

1. Flip between front and back cameras:

await controller.flipCamera();

1. Turn flash on or off:

await controller.toggleFlash();

1. Pause or resume camera stream and scanner:

await controller.pauseCamera();
await controller.resumeCamera();