Flutter检查连接网络connectivity_plus实现步骤

dependencies:
  flutter:
    sdk: flutter
  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^1.0.2
  connectivity_plus: ^4.0.1

android {
    ...
    defaultConfig {
        applicationId "com.example.flutter_application_connectivity"
        minSdkVersion 19 //flutter.minSdkVersion
          targetSdkVersion flutter.targetSdkVersion
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
    }

class _ConnectivityPageState extends State<ConnectivityPage> {
  // Connectivity 对象
  final Connectivity _connectivity = Connectivity();

// 消息订阅
  late StreamSubscription<ConnectivityResult> _subscription;

// 初始返回的网络状态
  ConnectivityResult? _connectivityStatus;

// 初始化
  Future<void> _init() async {
    try {
      // 方式1：单次请求检查
      final connectivityResult = await _connectivity.checkConnectivity();
      _updateConnectionStatus(connectivityResult);
    } on PlatformException catch (e) {
      print(e);
      print('连接网络出现了异常');
    }
  }

// 初始化
  Future<void> _init() async {
    try {
      // 方式1：单次请求检查
      // final connectivityResult = await _connectivity.checkConnectivity();
      // _updateConnectionStatus(connectivityResult);
      // 方式2：状态订阅
      _subscription =
          _connectivity.onConnectivityChanged.listen(_updateConnectionStatus);
    } on PlatformException catch (e) {
      print(e);
      print('连接网络出现了异常');
    }
  }

Future<void> _updateConnectionStatus(ConnectivityResult result) async {
    setState(() {
      _connectivityStatus = result;
    });
    if (result == ConnectivityResult.mobile) {
      print('成功连接移动网络');
    } else if (result == ConnectivityResult.wifi) {
      print('成功连接WIFI');
    } else if (result == ConnectivityResult.ethernet) {
      print('成功连接到以太网');
    } else if (result == ConnectivityResult.vpn) {
      print('成功连接vpn网络');
    } else if (result == ConnectivityResult.bluetooth) {
      print('成功连接蓝牙');
    } else if (result == ConnectivityResult.other) {
      print('成功连接除以上以外的网络');
    } else if (result == ConnectivityResult.none) {
      print('没有连接到任何网络');
    }
  }

@override
  void initState() {
    super.initState();
    _init();
  }

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

@override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('网路连接检查'),
      ),
      body: Center(
        child: Column(
          children: [
            const Text('状态'),
            Text(_connectivityStatus?.toString() ?? "未知"),
          ],
        ),
      ),
    );
  }