在颤振中从 HiveDB 检索缓存的 api 数据时出错

Question

我正在尝试在我的 Flutter 应用程序中实现 API 数据缓存，以启用应用程序的离线使用。但是，当我尝试返回数据时，它给了我一个 type '_InternalLinkedHashMap<dynamic, dynamic>' is not a subtype of type 'Map<String, dynamic>' 错误。

我已验证存储在 hive DB 中的数据是我收到的 api 数据。

!!IMPORTANT!! 这个错误发生的方式很奇怪。它仅在执行 FLUTTER RESTART 并导航到此页面时显示此错误。但是，如果我通过连接到互联网然后导航回主页来获取 API 数据，然后关闭我的网络连接并导航回此页面，则不会显示此错误。

对解决此问题的任何帮助将不胜感激。谢谢:)

我在下面附上了我的代码：

API 类

class HTTPService {

  Future<List<DriverStandings>> getDrivers(String year) async {
    final String urlStr =
        'https://ergast.com/api/f1/' + year + '/driverStandings.json';
    final Uri url = Uri.parse(urlStr);
    try {
      final response = await http.get(url);
      if (response.statusCode == 200) {
        List<dynamic> result = jsonDecode(response.body)["MRData"]
            ["StandingsTable"]["StandingsLists"][0]["DriverStandings"];
        Hive.box('API_DATA').put('drivers ' + year, result);
        List<DriverStandings> drivers = result
            .map((dynamic driver) => DriverStandings.fromJson(driver))
            .toList();

        return drivers;
      } else {
        throw Exception("Failed to load");
      }
    } catch (SocketExceptionError) {
      print('catching');
      List<dynamic> cacheResult =
          Hive.box('API_DATA').get('drivers ' + year, defaultValue: []);
      if (cacheResult.isNotEmpty) {
        print('is not empty');
        print(cacheResult);
        List<DriverStandings> drivers = cacheResult
            .map((dynamic driver) => DriverStandings.fromJson(driver))
            .toList();
        return drivers;
      } else {
        return [
          DriverStandings(
              points: 'null',
              driver: Driver(
                  familyName: 'null',
                  permanentNumber: 'null',
                  code: 'null',
                  givenName: 'null'),
              wins: 'null')
        ];
      }
    }
  }
}

模型类

class DriverStandings {
  String points;
  String wins;
  Driver driver;

  DriverStandings(
      {required this.points, required this.driver, required this.wins});

  factory DriverStandings.fromJson(Map<String, dynamic> json) {
    return DriverStandings(
        points: json['points'],
        driver: Driver.fromJson(json['Driver']),
        wins: json['wins']);
  }
}

class Driver {
  String code;
  String givenName;
  String familyName;
  String permanentNumber;

  Driver(
      {required this.familyName,
      required this.permanentNumber,
      required this.code,
      required this.givenName});

  factory Driver.fromJson(Map<String, dynamic> json) {
    return Driver(
        familyName: json['familyName'],
        permanentNumber: json['permanentNumber'],
        code: json['code'],
        givenName: json['givenName']);
  }
}

要展示的未来建筑

FutureBuilder(
                            future: httpService.getDrivers('current'),
                            builder: (BuildContext context,
                                AsyncSnapshot<List<DriverStandings>> snapshot) {
                              if (snapshot.hasData) {
                                return ListView.separated(
                                  itemCount: snapshot.data!.length,
                                  itemBuilder: (context, index) {
                                    if (driver.points == 'null') {
                                       return NoInternetError();
                                    }
                                    return DriverWidget(
                                        givenName: snapshot
                                            .data![index].driver.givenName,
                                        familyName: snapshot
                                            .data![index].driver.familyName,
                                        code: snapshot.data![index].driver.code,
                                        permanentNumber: snapshot.data![index]
                                            .driver.permanentNumber,
                                        points: snapshot.data![index].points,
                                        wins: snapshot.data![index].wins);
                                  },
                                  separatorBuilder:
                                      (BuildContext context, int index) {
                                    return SizedBox(height: 30.0);
                                  },
                                );
                              } else if (snapshot.hasError) {
                                return Text(
                                  snapshot.error.toString(),
                                  style: TextStyle(color: Colors.white),
                                );
                              }
                              return CircularProgressIndicator();
                            },
                          )