Flutter数据缓存管理插件riverpod_cache的使用

Flutter数据缓存管理插件riverpod_cache的使用

1. 整理后的内容中关于“Flutter数据缓存管理插件riverpod_cache的使用”的完整示例demo

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:riverpod_annotation/riverpod_annotation.dart';
import 'package:riverpod_cache/riverpod_cache.dart';
import 'package:shared_preferences/shared_preferences.dart';

part 'main.g.dart';

[@riverpod](/user/riverpod)
SharedPreferences sharedPreferences(SharedPreferencesRef ref) {
  throw UnimplementedError();
}

[@riverpod](/user/riverpod)
Stream<TodoResponse> todo(TodoRef ref) {
  return ref.cacheFirstOfflinePersistence(
    key: 'todo',
    future: () async {
      await Future.delayed(const Duration(seconds: 2));
      final response = await Dio().get(
        'https://jsonplaceholder.typicode.com/todos/1',
      );

      final result = TodoResponse.fromJson(response.data);

      return result;
    },
    sharedPreferences: ref.read(sharedPreferencesProvider),
    fromJson: TodoResponse.fromJson,
    toJson: (object) => object.toJson(),
  );
}

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  final sharedPreferences = await SharedPreferences.getInstance();
  runApp(
    ProviderScope(
      overrides: [
        sharedPreferencesProvider.overrideWithValue(sharedPreferences),
      ],
      child: const MainApp(),
    ),
  );
}

class MainApp extends StatelessWidget {
  const MainApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: HomePage(),
    );
  }
}

class HomePage extends ConsumerWidget {
  const HomePage({
    super.key,
  });

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final todoProvider = todoProvider;
    final todoState = ref.watch(todoProvider);

    return Scaffold(
      appBar: AppBar(
        title: const Text('Riverpod Cache Example'),
      ),
      body: RefreshIndicator(
        onRefresh: () async {
          ref.refresh(todoProvider.future);
          return;
        },
        child: SingleChildScrollView(
          physics: const AlwaysScrollableScrollPhysics(),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              Text(
                'Todo Data',
                style: Theme.of(context).textTheme.headlineMedium,
              ),
              todoState.when(
                data: (data) {
                  return Text(
                    const JsonEncoder.withIndent('  ').convert(data.toJson()),
                  );
                },
                error: (error, _) {
                  return Text(error.toString());
                },
                loading: () {
                  return const Center(
                    child: CircularProgressIndicator(),
                  );
                },
              ),
            ],
          ),
        ),
      ),
    );
  }
}

2. 参考我提供的内容和示例代码回答“Flutter数据缓存管理插件riverpod_cache的使用”对应的内容

标题：Flutter数据缓存管理插件riverpod_cache的使用

内容如下：

• 简介

  • 添加了对 Riverpod 提供者的离线持久化支持。
  • 目标是解决 Riverpod 缓存和离线持久化的问题。

• 功能

  • ✅ 缓存 FutureProvider
  • ✅ 缓存 StreamProvider
  • ✅ 缓存 StateNotifierProvider
  • ✅ 缓存 StateProvider
  • ✅ 更多…

• 开始使用

  • 需要在 pubspec.yaml 文件中添加 riverpod_cache 作为依赖项。

  dependencies:
    riverpod_cache: ^0.0.2
  

• 使用示例

  import 'package:riverpod_cache/riverpod_cache.dart';
  
  [@riverpod](/user/riverpod)
  SharedPreferences sharedPreferences(SharedPreferencesRef ref) {
    throw UnimplementedError();
  }
  
  [@riverpod](/user/riverpod)
  Stream<TodoResponse> todo(TodoRef ref) {
    return ref.cacheFirstOfflinePersistence(
      key: 'todo',
      future: () async {
        await Future.delayed(const Duration(seconds: 2));
        final response = await Dio().get(
          'https://jsonplaceholder.typicode.com/todos/1',
        );
  
        final result = TodoResponse.fromJson(response.data);
  
        return result;
      },
      sharedPreferences: ref.read(sharedPreferencesProvider),
      fromJson: TodoResponse.fromJson,
      toJson: (object) => object.toJson(),
    );
  }
  
  Future<void> main() async {
    WidgetsFlutterBinding.ensureInitialized();
    final sharedPreferences = await SharedPreferences.getInstance();
    runApp(
      ProviderScope(
        overrides: [
          sharedPreferencesProvider.overrideWithValue(sharedPreferences),
        ],
        child: const MainApp(),
      ),
    );
  }