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1. 引入插件
   官方网址：https://pub.dev/packages/connectivity_plus
   
2. 导入头文件

import 'package:connectivity_plus/connectivity_plus.dart';

3. 用StreamSubscription订阅网络监听

late StreamSubscription<List<ConnectivityResult>> _subscription;@override void initState() { super.initState(); // 必须要有订阅，如果没有订阅的话，那下次再进来，就检测不到网络的变化了_subscription =  Connectivity().onConnectivityChanged.listen((List<ConnectivityResult> result){print(result);if (result.contains(ConnectivityResult.wifi)) {setState(() {_stateText = "网络连接的Wifi";});} else if (result.contains(ConnectivityResult.none)) {setState(() {_stateText = "没有网络连接";});} else {setState(() {_stateText = "检测中";});}});}

4. dispose时，取消订阅

@override void dispose() { _subscription.cancel();super.dispose(); }

5. 完整代码案例

import 'dart:async';import 'package:flutter/material.dart';
import 'package:connectivity_plus/connectivity_plus.dart';class ConnectivityDemo extends StatefulWidget {const ConnectivityDemo({super.key});@overrideState<ConnectivityDemo> createState() => _ConnectivityDemoState();
}class _ConnectivityDemoState extends State<ConnectivityDemo> {late StreamSubscription<List<ConnectivityResult>> _subscription;String _stateText = "检测网络中";@override void initState() { super.initState(); // 必须要有订阅，如果没有订阅的话，那下次再进来，就检测不到网络的变化了_subscription =  Connectivity().onConnectivityChanged.listen((List<ConnectivityResult> result){print(result);if (result.contains(ConnectivityResult.wifi)) {setState(() {_stateText = "网络连接的Wifi";});} else if (result.contains(ConnectivityResult.none)) {setState(() {_stateText = "没有网络连接";});} else {setState(() {_stateText = "检测中";});}});}@override void dispose() { _subscription.cancel();super.dispose(); }@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text("网络监听"),),body: Center(child: Text(_stateText)),);}
}

6. 效果图如下：