迟答，但用这个包来检查。 包名:data_connection_checker

在你的酒吧里。yuml文件:

dependencies:
    data_connection_checker: ^0.3.4

创建一个名为connection的文件。达特，随便你叫什么都行。 导入包:

import 'package:data_connection_checker/data_connection_checker.dart';

检查是否有网络连接:

print(await DataConnectionChecker().hasConnection);

要检查你是否可以上网，即使你连接了wifi，也可以使用下面的功能。

Future<bool> checkInternetStatus() async {
    try {
      final url = Uri.https('google.com');
      var response = await http.get(url);
      if (response.statusCode == 200) {
        return true;
      } else {
        return false;
      }
    } catch (e) {
      return false;
    }
  }

还要添加http: ^0.13.5依赖项 然后导入'package:http/http。Dart '作为http;

迟答，但用这个包来检查。 包名:data_connection_checker

在你的酒吧里。yuml文件:

dependencies:
    data_connection_checker: ^0.3.4

创建一个名为connection的文件。达特，随便你叫什么都行。 导入包:

import 'package:data_connection_checker/data_connection_checker.dart';

检查是否有网络连接:

print(await DataConnectionChecker().hasConnection);

使用observe_internet_connectivity包。

可用的特性

检查设备是否有互联网连接

  final hasInternet = await InternetConnectivity().hasInternetConnection;
  if (hasInternet) {
    //You are connected to the internet
  } else {
    //"No internet connection
  }

通过流收听互联网连接变化

  final subscription =
      InternetConnectivity().observeInternetConnection.listen((bool hasInternetAccess) {
        if(!hasInternetAccess){
          showToast('No Internet Connection');
        }
      });

   await Future.delayed(const Duration(seconds: 10 ));
   subscription.cancel();

使用InternetConnectivityListener监听flutter小部件内的互联网连接变化

    return InternetConnectivityListener(
      connectivityListener: (BuildContext context, bool hasInternetAccess) {
        if (hasInternetAccess) {
          context.showBanner('You are back Online!', color: Colors.green);
        } else {
          context.showBanner('No internet connection', color: Colors.red);
        }
      },
      child: Scaffold(
        body: Container(),
      ),
    );

使用InternetConnectivityBuilder构建互联网连接感知小部件

    return InternetConnectivityBuilder(
      connectivityBuilder: (BuildContext context, bool hasInternetAccess, Widget? child) { 
        if(hasInternetAccess) {
          return OnlineWidget();
        } else {
          return OfflineWidget();
        }
      },
      child: ChildWidget(),
    );

这是我的解决方案，它检查互联网连接以及数据连接，我希望你喜欢它。

First of all add dependencies in your pubsec.yaml

dependencies:        
    data_connection_checker:

And Here Is The main.dart Of My Solution

import 'dart:async';

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

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "Data Connection Checker",
      home: HomePage(),
    );
  }
}

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  StreamSubscription<DataConnectionStatus> listener;

  var Internetstatus = "Unknown";

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
//    _updateConnectionStatus();
      CheckInternet();
  }

  @override
  void dispose() {
    // TODO: implement dispose
    listener.cancel();
    super.dispose();
  }

  CheckInternet() async {
    // Simple check to see if we have internet
    print("The statement 'this machine is connected to the Internet' is: ");
    print(await DataConnectionChecker().hasConnection);
    // returns a bool

    // We can also get an enum instead of a bool
    print("Current status: ${await DataConnectionChecker().connectionStatus}");
    // prints either DataConnectionStatus.connected
    // or DataConnectionStatus.disconnected

    // This returns the last results from the last call
    // to either hasConnection or connectionStatus
    print("Last results: ${DataConnectionChecker().lastTryResults}");

    // actively listen for status updates
    listener = DataConnectionChecker().onStatusChange.listen((status) {
      switch (status) {
        case DataConnectionStatus.connected:
          Internetstatus="Connectd TO THe Internet";
          print('Data connection is available.');
          setState(() {

          });
          break;
        case DataConnectionStatus.disconnected:
          Internetstatus="No Data Connection";
          print('You are disconnected from the internet.');
          setState(() {

          });
          break;
      }
    });

    // close listener after 30 seconds, so the program doesn't run forever
//    await Future.delayed(Duration(seconds: 30));
//    await listener.cancel();
    return await await DataConnectionChecker().connectionStatus;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Data Connection Checker"),
      ),
      body: Container(
        child: Center(
          child: Text("$Internetstatus"),
        ),
      ),
    );
  }
}

import 'dart:async';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:app_settings/app_settings.dart';
import 'package:connectivity/connectivity.dart';

class InternetConnect extends StatefulWidget {
  @override
  InternetConnectState createState() => InternetConnectState();
}

class InternetConnectState extends State<InternetConnect> {
  ConnectivityResult previous;
  bool dialogshown = false;
  StreamSubscription connectivitySubscription;

  Future<bool> checkinternet() async {
    try {
      final result = await InternetAddress.lookup('google.com');
      if (result.isNotEmpty && result[0].rawAddress.isNotEmpty) {
        return Future.value(true);
      }
    } on SocketException catch (_) {
      return Future.value(false);
    }
  }

  void checkInternetConnect(BuildContext context) {
    connectivitySubscription = Connectivity()
        .onConnectivityChanged
        .listen((ConnectivityResult connresult) {
      if (connresult == ConnectivityResult.none) {
        dialogshown = true;
        showDialog(
            context: context, barrierDismissible: false, child: alertDialog());
      } else if (previous == ConnectivityResult.none) {
        checkinternet().then((result) {
          if (result == true) {
            if (dialogshown == true) {
              dialogshown = false;
              Navigator.pop(context);
            }
          }
        });
      }

      previous = connresult;
    });
  }

  AlertDialog alertDialog() {
    return AlertDialog(
      title: Text('ERROR'),
      content: Text("No Internet Detected."),
      actions: <Widget>[
        FlatButton(
          // method to exit application programitacally

          onPressed: () {
            AppSettings.openWIFISettings();
          },
          child: Text("Settings"),
        ),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

    and you can use this method in init of any class

@override
void initState() {
  // TODO: implement initState
  InternetConnectState().checkInternetConnect(context);
  super.initState();
}