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';
import 'package:vitalapp/components/appbar.dart';
import 'dart:math' as math;

class QRViewExample extends StatefulWidget {
  final Function(String) onScanSuccess;
  final bool isBarcode;
  const QRViewExample({
    Key? key,
    required this.onScanSuccess,
    this.isBarcode = false,
  }) : super(key: key);

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

class _QRViewExampleState extends State<QRViewExample> {
  Barcode? result;
  QRViewController? controller;
  final GlobalKey qrKey = GlobalKey(debugLabel: 'QR');
  CameraFacing _cameraFacing = CameraFacing.front;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: VAppBar(
        titleText: "扫一扫",
        actions: [
          IconButton(
            onPressed: () async {
              await controller?.flipCamera();
              await Future.delayed(Duration(milliseconds: 500));
              setState(() {
                _cameraFacing = _cameraFacing == CameraFacing.front
                    ? CameraFacing.back
                    : CameraFacing.front;
              });
            },
            icon: Icon(
              Icons.change_circle_outlined,
              color: Colors.white,
              size: 36,
            ),
          ),
          SizedBox(
            width: 8,
          ),
        ],
      ),
      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) {
    return Transform(
      transform:
          Matrix4.rotationY(_cameraFacing == CameraFacing.front ? math.pi : 0),
      alignment: Alignment.center,
      child: QRView(
        key: qrKey,
        cameraFacing: _cameraFacing,
        onQRViewCreated: _onQRViewCreated,
        overlay: QrScannerOverlayShape(
          borderColor: Theme.of(context).colorScheme.primary,
          borderRadius: 10,
          borderLength: 30,
          borderWidth: 10,
          // cutOutSize: 400,
          cutOutWidth: 300,
          cutOutHeight: 300,
        ),
        formatsAllowed: widget.isBarcode
            ? [
                ///一维码则指定使用128的格式，会识别快一点
                // BarcodeFormat.code128,
                BarcodeFormat.qrcode,
              ]
            : [],
        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.onScanSuccess.call(event.code!);
    });
  }
}