Flutter二维码生成与扫描插件qris的使用

qris 是一个用于解析QR Indonesian Standard (QRIS) 代码的Flutter插件。它能够将读取到的QRIS码分解成有用的信息，如商户名称、交易金额等。

功能

• 解析QRIS码为各种有用信息，包括QRIS类型、商户名称、交易金额和各类商户信息。

使用示例

从字符串解析QRIS数据

假设你已经通过某种QR阅读工具获取了一个QRIS码，并将其存储在变量 qrisData 中：

final qris = QRIS(qrisData);

debugPrint(qris.merchantName); // 输出: Baznas

qris.merchants.forEach((merchant) {
  debugPrint("${merchant.globallyUniqueIdentifier} | ${merchant.merchantCriteria.toString()}");
});
// 输出: ID.CO.SHOPEE.WWW | QRISMerchantCriteria.large

debugPrint(qris.pointOfInitiation?.toString());
// 输出: QRISInitiationPoint.staticCode

从图片文件或相册中读取QRIS数据

推荐使用 barcode_finder 插件来实现从图片文件或相册中读取QRIS数据。以下是一个修改后的示例（该示例使用了 file_picker 来选择文件，你可以替换为 image_picker）：

import 'package:barcode_finder/barcode_finder.dart' as bf;
import 'package:image_picker/image_picker.dart';

Future<QRIS?> scanFile() async {
  final pickedFile = await FilePicker.platform.pickFiles();
  if (pickedFile != null) {
    final filePath = pickedFile.files.single.path;
    if (filePath != null) {
      final scannedData = await bf.BarcodeFinder.scanFile(
        path: filePath,
        formats: [bf.BarcodeFormat.QR_CODE],
      );
      if (scannedData != null) {
        return QRIS(scannedData);
      }
    }
  }
  return null;
}

完整示例Demo

以下是一个完整的Flutter应用程序示例，展示了如何使用 qris 插件进行二维码的扫描和解析：

// ignore_for_file: avoid_print, use_key_in_widget_constructors

import 'package:barcode_finder/barcode_finder.dart' as bf;
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:mobile_scanner/mobile_scanner.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:qris/qris.dart';

void main() {
  runApp(const QRISDemoApp());
}

class QRISDemoApp extends StatelessWidget {
  const QRISDemoApp();

  @override
  Widget build(BuildContext context) {
    const defaultBorder = OutlineInputBorder();

    return MaterialApp(
      theme: ThemeData(
        primarySwatch: Colors.blue,
        elevatedButtonTheme: const ElevatedButtonThemeData(
          style: ButtonStyle(
            iconColor: MaterialStatePropertyAll(Colors.white),
          ),
        ),
        inputDecorationTheme: const InputDecorationTheme(
          border: defaultBorder,
          focusedBorder: defaultBorder,
          enabledBorder: defaultBorder,
          errorBorder: defaultBorder,
          focusedErrorBorder: defaultBorder,
          isDense: true,
          contentPadding: EdgeInsets.symmetric(horizontal: 12.0, vertical: 8.0),
        ),
        floatingActionButtonTheme: const FloatingActionButtonThemeData(
          foregroundColor: Colors.white,
        ),
        listTileTheme: ListTileThemeData(
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(16.0),
            side: const BorderSide(color: Colors.black12),
          ),
        ),
      ),
      home: const QRISDemoPage(),
    );
  }
}

class QRISDemoPage extends StatefulWidget {
  const QRISDemoPage();

  @override
  State<QRISDemoPage> createState() => _QRISDemoPageState();
}

class _QRISDemoPageState extends State<QRISDemoPage> {
  QRIS? _qris;

  late final resultController = TextEditingController();

  @override
  void dispose() {
    resultController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('QRIS Scanner Demo')),
      body: Padding(
        padding: const EdgeInsets.all(24.0),
        child: Column(
          children: [
            TextField(
              decoration: InputDecoration(
                labelText: 'Reading Result (Raw)',
                suffixIcon: IconButton(
                  icon: const Icon(Icons.copy),
                  onPressed: () {
                    final result = resultController.text.trim();
                    if (result.isEmpty) return;
                    Clipboard.setData(ClipboardData(text: result));
                  },
                ),
              ),
              controller: resultController,
              readOnly: true,
              maxLines: 5,
            ),
            const SizedBox(height: 24.0),
            Expanded(
              child: Builder(
                builder: (_) {
                  final qris = _qris;
                  if (qris == null) {
                    return const Center(
                      child: Text(
                        'See scan results here',
                        textAlign: TextAlign.center,
                      ),
                    );
                  }
                  final map = qris.toEncodable().entries;
                  return ListView.separated(
                    separatorBuilder: (_, __) => const SizedBox(height: 12.0),
                    itemCount: map.length,
                    itemBuilder: (_, idx) {
                      final entry = map.elementAt(idx);
                      final value = '${entry.value}';
                      return ListTile(
                        leading: Text(
                          '[${entry.key}]',
                          style: const TextStyle(
                            fontWeight: FontWeight.bold,
                            color: Colors.blue,
                          ),
                        ),
                        title: Text(value),
                        trailing: IconButton(
                          onPressed: () {
                            if (value.isEmpty) return;
                            Clipboard.setData(ClipboardData(text: value));
                          },
                          icon: const Icon(Icons.copy),
                        ),
                      );
                    },
                  );
                },
              ),
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          Permission.camera.request().then((permission) {
            if (!permission.isGranted) {
              if (permission.isPermanentlyDenied) openAppSettings();
              return;
            }
            Navigator.of(context).push(
              MaterialPageRoute(builder: (_) => const QRISScannerPage()),
            ).then((result) {
              if (result is QRIS) {
                resultController.text = result.toString();
                setState(() {
                  _qris = result;
                });
              }
            });
          });
        },
        child: const Icon(Icons.qr_code_2),
      ),
    );
  }
}

class QRISScannerPage extends StatefulWidget {
  const QRISScannerPage();

  @override
  State<QRISScannerPage> createState() => _QRISScannerPageState();
}

class _QRISScannerPageState extends State<QRISScannerPage> with WidgetsBindingObserver {
  late final MobileScannerController controller = MobileScannerController(
    formats: [BarcodeFormat.qrCode],
  );

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    switch (state) {
      case AppLifecycleState.resumed:
        controller.start();
        break;
      case AppLifecycleState.inactive:
        controller.stop();
        break;
      case AppLifecycleState.paused:
        controller.stop();
        break;
      case AppLifecycleState.detached:
        break;
    }
  }

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

  void onDetect(BarcodeCapture barcodes) {
    for (var barcode in barcodes.barcodes) {
      final rawValue = barcode.rawValue;
      if (rawValue != null) {
        try {
          final qris = QRIS(rawValue);
          Navigator.of(context).pop(qris);
          break;
        } catch (_) {
          print(_);
        }
      }
    }
  }

  void toggleFlash() {
    if (controller.hasTorch) {
      controller.toggleTorch();
    }
  }

  Future<void> readFromImage() async {
    final storagePermission = await Permission.storage.request();
    if (!storagePermission.isGranted) {
      if (storagePermission.isPermanentlyDenied) openAppSettings();
      return;
    }
    final xFile = await ImagePicker().pickImage(source: ImageSource.gallery);
    final filePath = xFile?.path;
    if (filePath != null) {
      final data = await bf.BarcodeFinder.scanFile(
        path: filePath,
        formats: [bf.BarcodeFormat.QR_CODE],
      );
      if (data != null) {
        Navigator.of(context).pop(QRIS(data));
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('QR Scanner')),
      body: Stack(
        children: [
          Center(child: MobileScanner(controller: controller, onDetect: onDetect)),
          Padding(
            padding: const EdgeInsets.only(bottom: 64.0),
            child: Align(
              alignment: Alignment.bottomCenter,
              child: Row(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                children: [
                  ValueListenableBuilder(
                    valueListenable: controller.torchState,
                    builder: (context, state, _) {
                      late final Widget icon;
                      switch (state) {
                        case TorchState.off:
                          icon = const Icon(Icons.flash_on);
                          break;
                        case TorchState.on:
                          icon = const Icon(Icons.flash_off);
                          break;
                      }
                      return ElevatedButton(onPressed: toggleFlash, child: icon);
                    },
                  ),
                  ElevatedButton(onPressed: readFromImage, child: const Icon(Icons.image)),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}

以上代码提供了一个完整的Flutter应用示例，展示了如何使用 qris 插件进行二维码的扫描和解析。你可以根据需要进一步修改和完善这个示例。