Flutter 检测网络连接

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

class ConnectivityPage extends StatefulWidget {
  ConnectivityPage({Key key}) : super(key: key);

  _ConnectivityPageState createState() => _ConnectivityPageState();
}

class _ConnectivityPageState extends State<ConnectivityPage> {
  //网络状态描述
  String _connectStateDescription;

  var subscription;

  @override
  void initState() {
    super.initState();
    //监测网络变化
    subscription = Connectivity()
        .onConnectivityChanged
        .listen((ConnectivityResult result) {
      if (result == ConnectivityResult.mobile) {
        setState(() {
          _connectStateDescription = "手机网络";
        });
      } else if (result == ConnectivityResult.wifi) {
        setState(() {
          _connectStateDescription = "Wifi网络";
        });
      } else {
        setState(() {
          _connectStateDescription = "无网络";
        });
      }
      print(_connectStateDescription);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("监测网络")),
      body: Center(
        // 显示网络状态
        child: Text("$_connectStateDescription"),
      ),
    );
  }

  @override
  void dispose() {
    super.dispose();
    //在页面销毁的时候一定要取消网络状态的监听
    subscription.cancle();
  }
}