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我正在 Flutter 中学习 Hive db。当我使用 Flutter packagespub run build_runner build命令时，它会在其中生成data.g.dart文件，但它有一个错误。

完整的错误：

{
    "resource": "/E:/Mywork/AndroidApps/hive_todo/lib/data.g.dart",
    "owner": "dart",
    "code": "non_abstract_class_inherits_abstract_member",
    "severity": 8,
    "message": "Missing concrete implementation of 'getter TypeAdapter.typeId'.\nTry implementing the missing method, or make the class abstract.",
    "source": "dart",
    "startLineNumber": 9,
    "startColumn": 7,
    "endLineNumber": 9,
    "endColumn": 18,
    "tags": []
}

data.g.dart 代码：

    // GENERATED CODE - DO NOT MODIFY BY HAND
    
    part of 'data.dart';
    
    // **************************************************************************
    // TypeAdapterGenerator
    // **************************************************************************
    
    class dataAdapter extends TypeAdapter<data> {
      @override
      data read(BinaryReader reader) {
        var numOfFields = reader.readByte();
        var fields = <int, dynamic>{
          for (var i = 0; i < numOfFields; i++) reader.readByte(): reader.read(),
        };
        return data(
          todo: fields[0] as String,
          val: fields[1] as int,
        );
      }
    
      @override
      void write(BinaryWriter writer, data obj) {
        writer
          ..writeByte(2)
          ..writeByte(0)
          ..write(obj.todo)
          ..writeByte(1)
          ..write(obj.val);
      }
    
    
    }

data.dart代码：


import 'package:hive/hive.dart';

part 'data.g.dart';

@HiveType()
class data {

@HiveField(0)
  final String todo;
@HiveField(1)
  final int val;

  data({this.todo,this.val});
}

主要方法代码：

import 'package:flutter/material.dart';
import 'package:hive/hive.dart';
import 'package:path_provider/path_provider.dart' as path_provider;

import 'data.dart';
import 'todo_page.dart';


void main() async {
  
  WidgetsFlutterBinding.ensureInitialized();
  final appDocumentDir = await path_provider.getApplicationDocumentsDirectory();
  Hive.init(appDocumentDir.path);
Hive.registerAdapter(dataAdapter());
  runApp(MyApp());
}

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  @override

  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Hive Todo',
      home: FutureBuilder(
        future: Hive.openBox('data'),
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.done) {
            if (snapshot.hasError)
              return Text(snapshot.error.toString());
            else
              return Todo_Page();
          }
          // Although opening a Box takes a very short time,
          // we still need to return something before the Future completes.
          else
            return Scaffold(backgroundColor: Colors.red);
        },
      ),
    );
   
  }
  
  @override
  void dispose() {
    Hive.close();
    super.dispose();
  }
}

如果我进行快速修复，那么错误就消失了，但是当我在 main 方法中注册适配器时

Hive.registerAdapter(dataAdapter(), 0);

它只会给出错误，因为typeId. 当我删除它时，

Hive.registerAdapter(dataAdapter());

那么它不会给出错误。但我想要typeId它。

我的pubspec.yaml：

name: hive_todo
description: A new Flutter project.

# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
version: 1.0.0+1

environment:
  sdk: ">=2.5.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter
  hive: ^1.2.0
  hive_flutter: ^0.2.1
  # For OS-specific directory paths
  path_provider: ^1.3.1
  

  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^0.1.2

dev_dependencies:
  flutter_test:
    sdk: flutter
  hive_generator: ^0.5.1
  build_runner:

# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec

# The following section is specific to Flutter.
flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  # assets:
  #  - images/a_dot_burr.jpeg
  #  - images/a_dot_ham.jpeg

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/assets-and-images/#resolution-aware.

  # For details regarding adding assets from package dependencies, see
  # https://flutter.dev/assets-and-images/#from-packages

  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  # fonts:
  #   - family: Schyler
  #     fonts:
  #       - asset: fonts/Schyler-Regular.ttf
  #       - asset: fonts/Schyler-Italic.ttf
  #         style: italic
  #   - family: Trajan Pro
  #     fonts:
  #       - asset: fonts/TrajanPro.ttf
  #       - asset: fonts/TrajanPro_Bold.ttf
  #         weight: 700
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.dev/custom-fonts/#from-packages
4

1 回答 1

2

hivedb/hive 我有一个类似的问题，并在GitHub页面上找到了这个解决方案：

在 pubspec.yaml 中，hive: 1.2.0在您的依赖项中使用不带克拉符号。

于 2020-03-27T03:13:15.300 回答