探索 `go_router_riverpod`：Flutter 中的强大路由管理和状态管理结合

import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
 
void main() {
  // 初始化 GoRouter
  GoRouter.setUrlPathStrategy(UrlPathStrategy.path);
 
  // 使用 ProviderScope 来启动应用程序，这会启动所有的 providers
  ProviderScope(
    child: MaterialApp.router(
      title: 'Flutter Demo',
      routerDelegate: GoRouterDelegate(), // 使用 GoRouter 的代理
      routeInformationParser: GoRouterInformationParser(), // 解析路由信息
    ),
  );
}
 
// 定义一个 provider 来管理用户状态
final userProvider = StateProvider<String?>((ref) => null);
 
// 定义一个 widget 来展示当前用户名
class UserGreeting extends ConsumerWidget {
  const UserGreeting({Key? key}) : super(key: key);
 
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final userName = ref.watch(userProvider);
    return Text(userName == null ? 'Guest' : 'Welcome, $userName!');
  }
}
 
// 一个简单的页面，展示当前用户和提供登录/注销的功能
class HomePage extends ConsumerWidget {
  const HomePage({Key? key}) : super(key: key);
 
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final userName = ref.watch(userProvider);
 
    void login(String name) => ref.read(userProvider.notifier).state = name;
    void logout() => ref.read(userProvider.notifier).state = null;
 
    return Scaffold(
      appBar: AppBar(title: const Text('Home Page')),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            UserGreeting(),
            const SizedBox(height: 20),
            if (userName == null) ...[
              ElevatedButton(
                onPressed: () => login('Alice'),
                child: const Text('Login as Alice'),
              ),
              const SizedBox(height: 10),
              ElevatedButton(
                onPressed: () => login('Bob'),
                child: const Text('Login as Bob'),
              ),
            ] else ...[
              ElevatedButton(
                onPressed: logout,
                child: const Text('Logout'),
              ),
            ],
          ],
        ),
      ),
    );
  }
}
 
// 定义路由
final routerProvider = Provider<GoRouter>((ref) {
  return GoRouter(
    routes: [
      GoRout