网络请求+模型处理

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import 'Counter.dart';

void main() {
  // runApp(const MyApp());
  runApp(
    MultiProvider(
      providers: [
        ChangeNotifierProvider(create: (_) => Counter()),
      ],
      child: const MyApp(),
    ),
  );
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    // setState(() {
    //   _counter++;
    // });
    context.read<Counter>().increment();
  }

  Future getHomePage() async {}

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    context.read<Counter>().requestData();
  }

  @override
  Widget build(BuildContext context) {
    context.read<Counter>().onReqList;
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            // const Text(
            //   // 'You have pushed the button this many times:',
            //   '${context.watch<Counter>().count}',
            // ),
            Text(
              // '${context.watch<Counter>().count}',
              '${context.watch<Counter>().model?.city ?? "-"}',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

业务控制器

import 'package:dio/dio.dart';
import 'package:flutter/material.dart';
import 'package:flutter_provide/tianqi.dart';

enum BaseCcontrollerStatus {
  empty,
  loading,
  success,
  fail,
}

class Counter with ChangeNotifier {
  int _count = 0;
  int get count => _count;

  WeaModel? _model;
  WeaModel? get model => _model;

  BaseCcontrollerStatus _status = BaseCcontrollerStatus.loading;
  BaseCcontrollerStatus get status => _status;

  void increment() {
    _count++;
    notifyListeners();
  }
}

extension Network on Counter {
  void onReqList() async {
    Future.delayed(const Duration(seconds: 2), () {
      _status = BaseCcontrollerStatus.success;
      // print('初始化请求啦:9999999');
      notifyListeners();
    });
  }
}

extension Network1 on Counter {
  void requestData() async {
    print('初始化请求啦');
    var dio = Dio();
    final response = await dio.get(
        'https://www.tianqiapi.com/free/day?appid=23035354&appsecret=8YvlPNrz');
    WeaModel model = WeaModel.fromJson(response.data);
    _model = model;
    print(response.data);
    print('哈哈${model.city}');
    print('初始化请求完成啦');
    notifyListeners();
  }
}
//https://pub.flutter-io.cn/packages/provider/example    provider使用例子

模型

class WeaModel {
  num? nums;
  String? cityid;
  String? city;
  String? date;
  String? week;
  String? updateTime;
  String? wea;
  String? weaImg;

  WeaModel(
      {this.nums,
      this.cityid,
      this.city,
      this.date,
      this.week,
      this.updateTime,
      this.wea,
      this.weaImg});

  WeaModel.fromJson(Map<String, dynamic> json) {
    nums = json['nums'];
    cityid = json['cityid'];
    city = json['city'];
    date = json['date'];
    week = json['week'];
    updateTime = json['update_time'];
    wea = json['wea'];
    weaImg = json['wea_img'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['nums'] = this.nums;
    data['cityid'] = this.cityid;
    data['city'] = this.city;
    data['date'] = this.date;
    data['week'] = this.week;
    data['update_time'] = this.updateTime;
    data['wea'] = this.wea;
    data['wea_img'] = this.weaImg;
    return data;
  }
}