VitalApp/lib/pages/widgets/qr_view_example.dart

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

class QRViewExample extends StatefulWidget {
  final Function(String) onPressed;

  const QRViewExample({Key? key, required this.onPressed}) : super(key: key);

  @override
  State<StatefulWidget> createState() => _QRViewExampleState();
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('扫一扫'),
      ),
      body: Column(
        children: <Widget>[
          Expanded(
            flex: 4,
            child: _buildQrView(
              context,
            ),
          ),
        ],
      ),
    );
  }

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

  @override
  void reassemble() {
    super.reassemble();
    controller?.pauseCamera();
    controller?.resumeCamera();
  }

  Widget _buildQrView(BuildContext context) {
    var scanArea = (MediaQuery.of(context).size.width < 400 ||
            MediaQuery.of(context).size.height < 400)
        ? 150.0
        : 300.0;
    return QRView(
      key: qrKey,
      onQRViewCreated: _onQRViewCreated,
      overlay: QrScannerOverlayShape(
        borderColor: Theme.of(context).colorScheme.primary,
        borderRadius: 10,
        borderLength: 30,
        borderWidth: 10,
        cutOutSize: scanArea,
      ),
      onPermissionSet: (ctrl, p) => _onPermissionSet(context, ctrl, p),
    );
  }

  void _onPermissionSet(BuildContext context, QRViewController ctrl, bool p) {
    logger.i("QRViewExample _onPermissionSet $p");
    if (!p) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(
          content: Text(
            'no Permission',
          ),
        ),
      );
    }
  }

  void _onQRViewCreated(QRViewController controller) {
    setState(() {
      this.controller = controller;
    });
    controller.scannedDataStream.listen((event) async {
      controller.dispose();
      widget.onPressed.call(event.code!);
    });
  }
}