Flutter Hive getter 没有为“hiveobjectmixin”类型定义答案

【问题标题】：Flutter Hive getter isn't defined for the type 'hiveobjectmixin'Flutter Hive getter 没有为“hiveobjectmixin”类型定义
【发布时间】：2021-10-19 11:32:24
【问题描述】：

在创建模型以在 2 个模型之间建立关系后，我无法从嵌套关系中获取字段数据

我有一个用户模型，其中包含其他模型作为事务，即HiveList，现在当我尝试使用以下代码从事务中获取cost 等字段时：

final Box<User> _user = Hive.box<User>('user');
print('${_user.values.first.transactions.first.cost}');

我得到这个错误：

错误：没有为类型“HiveObjectMixin”定义吸气剂“成本”。（[xxxx] 处的 undefined_getter lib/src/screens/dashboard/tabs/screen_transactions.dart:85)

型号：

@HiveType(typeId: 1)
class User extends HiveObject {
  @HiveField(0)
  late String nameFamily;

  @HiveField(1)
  late String apiToken;

  @HiveField(2)
  late String mobileNumber;

  @HiveField(3)
  late HiveList transactions;
}
@HiveType (typeId: 4)
class Transactions extends HiveObject {
  @HiveField(0)
  late int cost;

  @HiveField(1)
  late int type;

  @HiveField(2)
  late String dateTime;
}

适配器：

class UserAdapter extends TypeAdapter<User> {
  @override
  final int typeId = 1;

  @override
  User read(BinaryReader reader) {
    final numOfFields = reader.readByte();
    final fields = <int, dynamic>{
      for (int i = 0; i < numOfFields; i++) reader.readByte(): reader.read(),
    };
    return User()
      ..nameFamily = fields[0] as String
      ..apiToken = fields[1] as String
      ..mobileNumber = fields[2] as String
      ..transactions = (fields[5] as HiveList).castHiveList();
  }

  @override
  void write(BinaryWriter writer, User obj) {
    writer
      ..writeByte(6)
      ..writeByte(0)
      ..write(obj.nameFamily)
      ..writeByte(1)
      ..write(obj.apiToken)
      ..writeByte(2)
      ..write(obj.mobileNumber)
      ..writeByte(3)
      ..write(obj.transactions);
  }

  @override
  int get hashCode => typeId.hashCode;

  @override
  bool operator ==(Object other) =>
      identical(this, other) ||
      other is UserAdapter &&
          runtimeType == other.runtimeType &&
          typeId == other.typeId;
}
class WalletAdapter extends TypeAdapter<Wallet> {
  @override
  final int typeId = 3;

  @override
  Wallet read(BinaryReader reader) {
    final numOfFields = reader.readByte();
    final fields = <int, dynamic>{
      for (int i = 0; i < numOfFields; i++) reader.readByte(): reader.read(),
    };
    return Wallet()..total = fields[0] as int;
  }

  @override
  void write(BinaryWriter writer, Wallet obj) {
    writer
      ..writeByte(1)
      ..writeByte(0)
      ..write(obj.total);
  }

  @override
  int get hashCode => typeId.hashCode;

  @override
  bool operator ==(Object other) =>
      identical(this, other) ||
      other is WalletAdapter &&
          runtimeType == other.runtimeType &&
          typeId == other.typeId;
}

【问题讨论】：

标签： flutter dart flutter-hive

【解决方案1】：

我通过cast() 方法解决了这个问题，我应该将哪个类用作List，例如：

_user.values.first.transactions.cast().cost

【讨论】：