Информация о считывании кредитной карты Flutter NFC

Здравствуйте, я пытаюсь получить информацию о кредитной или дебетовой карте с помощью NFC на Flutter. Я буду выполнять платежные операции с этой информацией. Я могу справиться с этой частью самостоятельно, но у меня возникли проблемы с получением информации о карте. Можете ли вы помочь? Заранее благодарны за Вашу помощь.

Я получаю эту ошибку прямо сейчас Не удалось извлечь AID из ответа PPSE.

nfc_view_model.dart

    import 'package:flutter/foundation.dart';
    import 'package:flutter/services.dart';
    import 'package:get/get.dart';
    import 'package:nfc_manager/nfc_manager.dart';
    import 'package:nfc_manager/platform_tags.dart';

    class NfcViewModel extends GetxController {
    RxString message = ''.obs;

Future<void> startNFCReading() async {
try {
  final bool isAvailable = await NfcManager.instance.isAvailable();

  if (isAvailable) {
    message.value = 'NFC is available.';

    await NfcManager.instance.startSession(
      onDiscovered: (NfcTag tag) async {
        try {
          if (kDebugMode) {
            print('Tag found: ${tag.data}');
          }
          message.value = 'Tag found: ${tag.data}';

          final IsoDep? isoDep = IsoDep.from(tag);
          if (isoDep != null) {
            // PPSE (Proximity Payment System Environment) seçimi
            var ppseCommand = [
              0x00,
              0xA4,
              0x04,
              0x00,
              0x0E,
              0x32,
              0x50,
              0x41,
              0x59,
              0x2E,
              0x53,
              0x59,
              0x53,
              0x2E,
              0x44,
              0x44,
              0x46,
              0x30,
              0x31,
              0x00
            ];
            var ppseResponse = await isoDep.transceive(
                data: Uint8List.fromList(ppseCommand));
            if (kDebugMode) {
              print('PPSE Response: $ppseResponse');
            }
            if (ppseResponse.isEmpty) {
              message.value = 'PPSE Response is empty.';
              await NfcManager.instance.stopSession();
              return;
            }

            // PPSE yanıtını işle ve AID'yi al
            var aid = extractAidFromPpseResponse(ppseResponse);
            if (aid == null) {
              message.value = 'Failed to extract AID from PPSE response.';
              await NfcManager.instance.stopSession();
              return;
            }

            // AID seçim komutu
            var aidCommand = [
              0x00,
              0xA4,
              0x04,
              0x00,
              aid.length,
              ...aid,
              0x00
            ];
            var aidResponse = await isoDep.transceive(
                data: Uint8List.fromList(aidCommand));
            if (kDebugMode) {
              print('AID Response: $aidResponse');
            }
            if (aidResponse.isEmpty) {
              message.value = 'AID Response is empty.';
              await NfcManager.instance.stopSession();
              return;
            }

            // GET PROCESSING OPTIONS komutu
            var gpoCommand = [
              0x80,
              0xA8,
              0x00,
              0x00,
              0x02,
              0x83,
              0x00,
              0x00
            ];
            var gpoResponse = await isoDep.transceive(
                data: Uint8List.fromList(gpoCommand));
            if (kDebugMode) {
              print('GPO Response: $gpoResponse');
            }
            if (gpoResponse.isEmpty) {
              message.value = 'GPO Response is empty.';
              await NfcManager.instance.stopSession();
              return;
            }

            // RECORD okuma komutu
            var readRecordCommand = [0x00, 0xB2, 0x01, 0x0C, 0x00];
            var readRecordResponse = await isoDep.transceive(
                data: Uint8List.fromList(readRecordCommand));
            if (kDebugMode) {
              print('Read Record Response: $readRecordResponse');
            }
            if (readRecordResponse.isEmpty) {
              message.value = 'Read Record Response is empty.';
              await NfcManager.instance.stopSession();
              return;
            }

            // Kart bilgilerini ayıkla
            final cardDetails = parseCardDetails(readRecordResponse);
            message.value = cardDetails;

            await NfcManager.instance.stopSession();
          } else {
            message.value = 'IsoDep not supported on this tag.';
          }
        } catch (e) {
          message.value = 'Error: $e';
          await NfcManager.instance.stopSession(errorMessage: e.toString());
        }
      },
    );
  } else {
    message.value = 'NFC is not available.';
  }
 } catch (e) {
  message.value = e.toString();
 }
}

List<int>? extractAidFromPpseResponse(Uint8List response) {
try {
  int index = 0;
  while (index < response.length) {
    int tag = response[index++];
    int length = response[index++];
    if (tag == 0x4F) {
      // AID tag
      return response.sublist(index, index + length);
    }
    index += length;
  }
  return null;
} catch (e) {
  if (kDebugMode) {
    print('Error extracting AID: $e');
  }
  return null;
}
}

String parseCardDetails(Uint8List response) {
String hexString = response
    .map((e) => e.toRadixString(16).padLeft(2, '0'))
    .join()
    .toUpperCase();

// Yanıtın uzunluğunu kontrol edin
if (hexString.length < 20) {
  return 'Error: Insufficient data length. Response length is ${hexString.length}';
}

try {
  // Example extraction logic (adjust based on actual card data structure)
  final cardNumber =
      hexString.substring(0, 16); // Example: first 16 characters
  final expiryDate =
      hexString.substring(16, 20); // Example: next 4 characters
  return 'Card Number: $cardNumber, Expiry Date: $expiryDate';
} catch (e) {
  return 'Error parsing card details: $e';
}
}
}

nfc_screen.dart (код пользовательского интерфейса)

    import 'package:digipos/core/base/view/base_view.dart';
         import 'package:digipos/view/payment/nfc/view_model/nfc_view_model.dart';
         import 'package:digipos/view/widgets/appbar/custom_appbar_widget.dart';
         import 'package:flutter/material.dart';
import 'package:flutter_svg/flutter_svg.dart';
import 'package:get/get.dart';

import '../../../core/base/state/base_state.dart';
import '../../../core/constants/icons.dart';

class NfcScreen extends StatefulWidget {
  const NfcScreen({super.key});

  @override
  State<NfcScreen> createState() => _NfcScreenState();
}

class _NfcScreenState extends BaseState<NfcScreen> {
  final NfcViewModel _viewModel = Get.put(NfcViewModel());

  @override
  void initState() {
    super.initState();
    _viewModel.startNFCReading();
  }

  @override
  Widget build(BuildContext context) {
    return BaseView(
      viewModel: _viewModel,
      onPageBuilder: (context, dynamic viewModel) => scaffoldBody(),
    );
  }

  Scaffold scaffoldBody() {
    return Scaffold(
      appBar: const CustomAppBarWidget(appBarType: AppBarType.back),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            SvgPicture.asset(
              AppIcons.nfcPay.iconPath,
              width: dynamicHeight(0.25),
            ),
            const SizedBox(height: 20),
            Obx(
              () => Text(
                _viewModel.message.value,
                textAlign: TextAlign.center,
                style: const TextStyle(
                  fontWeight: FontWeight.bold,
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}