nowser/lib/component/qrscanner.dart

import 'dart:io';

import 'package:flutter/material.dart';
import 'package:qr_code_scanner/qr_code_scanner.dart';

import '../util/router_util.dart';

class QRScanner extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return _QRScanner();
  }

  static Future<String?> show(BuildContext context) async {
    return await RouterUtil.push(context, MaterialPageRoute(builder: (context) {
      return QRScanner();
    }));
  }
}

class _QRScanner extends State<QRScanner> {
  final GlobalKey qrKey = GlobalKey(debugLabel: 'QR');
  Barcode? result;
  QRViewController? controller;

  // In order to get hot reload to work we need to pause the camera if the platform
  // is android, or resume the camera if the platform is iOS.
  @override
  void reassemble() {
    super.reassemble();
    if (Platform.isAndroid) {
      controller!.pauseCamera();
    } else if (Platform.isIOS) {
      controller!.resumeCamera();
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: QRView(
        key: qrKey,
        onQRViewCreated: _onQRViewCreated,
      ),
    );
  }

  bool scanComplete = false;

  void _onQRViewCreated(QRViewController controller) {
    this.controller = controller;
    controller.scannedDataStream.listen((scanData) {
      if (!scanComplete) {
        scanComplete = true;
        RouterUtil.back(context, scanData.code);
      }
    });
  }

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