flutter - 如何在 hive 对象中编写自定义类对象？

Question

在flutter中使用hive时，我使用了我的自定义类对象Profile profile在 hive 对象中。

因此，最初，我将自定义类对象( Profile profile )设置为 null在 Hive 框中添加时。

以下是我的 Hive 类(class):

import 'dart:convert';
import 'package:hive/hive.dart';
import 'package:lpa_exam/src/model/listofexams.dart';
import 'package:lpa_exam/src/model/profile.dart';
part 'hiveprofile.g.dart';

@HiveType()
class PersonModel extends HiveObject{
  @HiveField(0)
  String language;

  @HiveField(1)
  String examName;

  @HiveField(2)
  int examId;

  @HiveField(3)
  Profile profile;

  @HiveField(4)
  ListExam listexam;

  @override
  String toString() {
    return jsonEncode({
      'language': this.language,
      'examName': this.examName,
      'examId': this.examId,
      'profile': this.profile,
      'listexam': this.listexam
    });
  }

  PersonModel(
      this.language, this.examName, this.examId, this.profile, this.listexam);
}

Profile类供引用:

class Profile {
  String name='';
  String lang='';
  String emailId='';
  String mobileNumber='';
  String state='';
  String city='';
  String district='';
  String pinCode='';
  String profilePic='';
  Profile(
      this.name,
      this.lang,
      this.emailId,
      this.mobileNumber,
      this.district,
      this.state,
      this.city,
      this.pinCode,this.profilePic);

  Profile.fromJson(Map<String, dynamic> json) {
    // print('fromjson:$json');
    if (json != null) {
      name = json['name'];
      lang = json['language'];
      emailId = json['emailId'];
      mobileNumber = json['mobileNumber'];
      district = json['district'];
      state = json['state'];
      city = json['city'];
      pinCode = json['pinCode'];
      profilePic=json['profilePic'];
    } else {
      print('in else profile from json');
      // name = '';
    }
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['name'] = this.name;
    data['language'] = this.lang;
    data['emailId'] = this.emailId;
    data['mobileNumber'] = this.mobileNumber;
    data['district'] = this.district;
    data['state'] = this.state;
    data['city'] = this.city;
    data['pinCode'] = this.pinCode;
    data['profilePic']=this.profilePic;
    return data;
  }
}

当我尝试像这样添加添加的对象时发生错误

item.add(PersonModel(label, null, null, Profile(), ListExam())); // label='English'

以下是发生的错误:

[VERBOSE-2:ui_dart_state.cc(157)] Unhandled Exception: HiveError: Cannot write, unknown type: Profile. Did you forget to register an adapter?

现在，有人可以指出我在这里做错了什么吗？

Answer 1

Hive 插件默认支持原语、列表和映射。要将它用于您自己的 Dart 对象，您需要生成一个 TypeAdapter。

您需要为您拥有的每个对象创建一个 TypeAdapter。所以你需要为 应用相同的东西公司简介 您为 所做的类(class)人物模型

part 'profile.g.dart';

@HiveType()
class Profile {
  @HiveField(0)
  String name;
  @HiveField(1)
  String lang;
  @HiveField(2)
  String emailId;
  @HiveField(3)
  String mobileNumber;
  @HiveField(4)
  String state;
  @HiveField(5)
  String city;
  @HiveField(6)
  String district;
  @HiveField(7)
  String pinCode;
  @HiveField(8)
  String profilePic;

  Profile(
      this.name,
      this.lang,
      this.emailId,
      this.mobileNumber,
      this.district,
      this.state,
      this.city,
      this.pinCode,this.profilePic);      


  Profile.fromJson(Map<String, dynamic> json) {
    // print('fromjson:$json');
    if (json != null) {
      name = json['name'];
      lang = json['language'];
      emailId = json['emailId'];
      mobileNumber = json['mobileNumber'];
      district = json['district'];
      state = json['state'];
      city = json['city'];
      pinCode = json['pinCode'];
      profilePic=json['profilePic'];
    } else {
      print('in else profile from json');
      // name = '';
    }
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['name'] = this.name;
    data['language'] = this.lang;
    data['emailId'] = this.emailId;
    data['mobileNumber'] = this.mobileNumber;
    data['district'] = this.district;
    data['state'] = this.state;
    data['city'] = this.city;
    data['pinCode'] = this.pinCode;
    data['profilePic']=this.profilePic;
    return data;
 }

}

如果您使用的是最新的配置单元版本，您还需要为您的 HiveType 提供一个类型 ID，例如

@HiveType(typeId: 0)

我看到您还有另一个名为 的自定义类列表考试 .您还需要为该类(class)做同样的事情