首页 > 解决方案 > Flutter 和 Hive 的奇怪问题

问题描述

我在 Flutter 应用程序中遇到了 Hive 数据库的几个问题:

  1. Hive.initFlutter()不管用。我收到以下错误:
[VERBOSE-2:ui_dart_state.cc(209)] Unhandled Exception: HiveError: You need to initialize Hive or provide a path to store the box.

我尝试使用 appPath 调用该方法,而没有,它没有区别!如果我使用Hive.init(appPath)而不是Hive.initFlutter()没有得到上述异常!这是flutter应用程序中的代码:(Init是一个有很多静态方法来初始化应用程序的类。它在FutureBuilder闪屏小部件setupLocalHiveDatabase()中调用。首先调用该方法来初始化Hive并打开所有框。)

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  // init Hive and open all boxes
  await Init.setupLocalHiveDatabase();

  runApp(MyApp());
}

  static setupLocalHiveDatabase() async {
    print('Setting up hive ...');
    var appDocDir = await getApplicationDocumentsDirectory();
    print('The application directory is: ${appDocDir.path}');
    _setupHive(appDocDir.path);
    print('Open all boxes ...');
    await Hive.openBox<CreditCard>(HiveBoxes.creditCard,
        compactionStrategy: (entries, deletedEntries) => deletedEntries > 10);
    await Hive.openBox<ConfigItem>(HiveBoxes.appConfig,
        compactionStrategy: (entries, deletedEntries) => deletedEntries > 10);
    await Hive.openBox<SupplierOverview>(HiveBoxes.supplier,
        compactionStrategy: (entries, deletedEntries) => deletedEntries > 20);
    await Hive.openBox<SubscriptionOverview>(HiveBoxes.subscription,
        compactionStrategy: (entries, deletedEntries) => deletedEntries > 20);
    await Hive.openBox<BscUserProfile>(HiveBoxes.bscUserProfile,
        compactionStrategy: (entries, deletedEntries) => deletedEntries > 10);
    await Hive.openBox<SyncJob>(HiveBoxes.syncJob,
        compactionStrategy: (entries, deletedEntries) => deletedEntries > 10);
    await Hive.openBox<SyncProtocol>(HiveBoxes.syncProtocol,
        compactionStrategy: (entries, deletedEntries) => deletedEntries > 20);
    await Hive.openBox<ClientDevice>(HiveBoxes.clientDevice,
        compactionStrategy: (entries, deletedEntries) => deletedEntries > 2);
    await Hive.openBox<ClientError>(HiveBoxes.clientError,
        compactionStrategy: (entries, deletedEntries) => deletedEntries > 10);

    print('done.');
  }


  static void _setupHive(String path) async {
    // We initialize Hive and we give it the current path
    print('Initializing Hive databases ...');
    //Hive.init(path);
    await Hive.initFlutter(path);
    print('Registering Hive Adapters...');
    Hive.registerAdapter(ConfigItemAdapter()); // ID 1
    Hive.registerAdapter(CreditCardAdapter()); // ID 2
    Hive.registerAdapter(SubscriptionOverviewAdapter()); // ID 3
    Hive.registerAdapter(SupplierOverviewAdapter()); // ID 4
    Hive.registerAdapter(ClientErrorAdapter()); // ID 5
    Hive.registerAdapter(BscUserProfileAdapter()); //ID 6
    Hive.registerAdapter(SyncJobAdapter()); //ID 7
    Hive.registerAdapter(PersonAdapter()); // ID 8
    Hive.registerAdapter(ContactDataAdapter()); // ID 9
    Hive.registerAdapter(SyncProtocolAdapter()); // ID 10
    Hive.registerAdapter(ClientDeviceAdapter()); // ID 11

    // Enum Types
    Hive.registerAdapter(SyncStatesAdapter()); // ID 101
    Hive.registerAdapter(SyncDirectionsAdapter()); // ID 102
    Hive.registerAdapter(ContractDataObjectTypesAdapter()); // ID 103
    Hive.registerAdapter(OperationResultsAdapter()); // ID 104
    Hive.registerAdapter(PlatformTypesAdapter()); // ID 106

    print('Done with Hive setup.');
  }

  1. 数据未正确保存

我有一个奇怪的情况,即应用程序重新启动(热重载或完全重启)后数据为空。这是保存对象后的输出

flutter: UserData: BscUserProfile(0031cd3c-5851-403c-9c11-7ea190db5abf, Debug Test User, debug@test.com, , , [])

如果我进行热重载,数据如下所示:

flutter: UserData: BscUserProfile(, , , , , [])

该对象在数据库中但为

这是飞镖代码(它在Init上面的类中)

  static _setupUser(String userEmail) async {
    var userBox = Hive.box<BscUserProfile>(HiveBoxes.bscUserProfile);
    //await userBox.deleteAll(userBox.keys);
    if (userBox.isEmpty) {
      // create a fake user for testing
      var user = BscUserProfile(
        bscUserEmail: userEmail,
        bscUserDisplayName: 'Debug Test User',
        bscUserId: Uuid().v4().toString(),
      );
      await userBox.put(user.bscUserId, user);
      GetIt.instance.registerSingleton(user);
      for (var user in userBox.values) {
        print('UserData: ${user.toString()}');
      }

      return;
    }
    // dump database
    for (var user in userBox.values) {
      print('UserData: ${user.toString()}');
    }
    var user = userBox.values.firstWhereOrNull((user) => user.bscUserEmail == userEmail);
    if (user != null) {
      GetIt.instance.registerSingleton(user);
      return;
    }
  }

如果我取消注释第二行以从框中删除(userBox.isEmpty)所有对象,它会正确跳转到然后显示正确的数据。重新加载后数据库不是空的而是显示空对象!

3. 更新不起作用 第三个问题也在Init课堂上。当应用程序启动时,我会保留一些设备特定的数据。更新后,应用程序重新启动后更新不会反映在数据库中。这里是一些打印语句的输出:

flutter: ClientDevice(e5634285-7e46-4eed-8d89-1a9b4cbfb94d, 93C259F6-EBE2-4079-9B99-E542B714B230, iPhone 11 Pro, iPhone, PlatformTypes.iOS, ios, 11.6, 16, en, gala.local, false, 172.16.63.186)
flutter: Device has changed!
flutter: Current device: ClientDevice(e5634285-7e46-4eed-8d89-1a9b4cbfb94d, 93C259F6-EBE2-4079-9B99-E542B714B230, iPhone 11 Pro, iPhone, PlatformTypes.iOS, iOS, 15.0, 16, en, gala.local, false, 172.16.63.186)
flutter: Persisted device: ClientDevice(e5634285-7e46-4eed-8d89-1a9b4cbfb94d, 93C259F6-EBE2-4079-9B99-E542B714B230, iPhone 11 Pro, iPhone, PlatformTypes.iOS, ios, 11.6, 16, en, gala.local, false, 172.16.63.186)

此处版本未更新:重新启动后显示11.6 ,然后使用15.0更新,但似乎没有持久化。

我不知道我在这里做错了什么,或者在初始化期间更改数据是否有问题,或者是否有Future / async问题。它很好奇。如果有人看到出了什么问题,将不胜感激。(我使用 AndroidStudio 和最新版本的 Dart 和 Flutter)

标签: flutterdart

解决方案


在没有路径的情况下调用它

喜欢

/// main
void main() async {
  /// db init
  await Hive.initFlutter();
....
}

我认为你可以使用你的调用结构,但你需要Hive.initFlutter()没有路径的 init


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