需求

connectivity_plus 雖然支援六平台，但使用上情境還是以mobile為主，桌機不太可能一直切換連線方式。
在手機app 的issue 有很多都是切換連線方式產生的，所以要知道手機裝置用什麼方式連線是很重要的。

connectivity_plus - Readme

connectivity_plus 可以分辨行動 網路連接 和 WiFi 連接

import 'package:connectivity_plus/connectivity_plus.dart';

final connectivityResult = await (Connectivity().checkConnectivity());
if (connectivityResult == ConnectivityResult.mobile) {
  // I am connected to a mobile network.
} else if (connectivityResult == ConnectivityResult.wifi) {
  // I am connected to a wifi network.
} else if (connectivityResult == ConnectivityResult.ethernet) {
  // I am connected to a ethernet network.
} else if (connectivityResult == ConnectivityResult.vpn) {
  // I am connected to a vpn network.
  // Note for iOS and macOS:
  // There is no separate network interface type for [vpn].
  // It returns [other] on any device (also simulator)
} else if (connectivityResult == ConnectivityResult.bluetooth) {
  // I am connected to a bluetooth.
} else if (connectivityResult == ConnectivityResult.other) {
  // I am connected to a network which is not in the above mentioned networks.
} else if (connectivityResult == ConnectivityResult.none) {
  // I am not connected to any network.
}

connectivity_plus - Install

直接在 pubspec.yaml 加上 connectivity_plus: ^4.0.2 ，然後pub get 

dependencies:
  connectivity_plus: ^4.0.2

connectivity_plus - Example

在 /lib/main.dart 加入 程式
import 'package:connectivity_plus/connectivity_plus.dart';

宣告變數和初始化

class _MyHomePageState extends State<MyHomePage> {
  ConnectivityResult _connectionStatus = ConnectivityResult.none;
  final Connectivity _connectivity = Connectivity();
  late StreamSubscription<ConnectivityResult> _connectivitySubscription;
...

@override
void initState() {
    _connectivitySubscription =
        _connectivity.onConnectivityChanged.listen(_updateConnectionStatus);
}

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

  Future<void> initConnectivity() async {
    late ConnectivityResult result;
    // Platform messages may fail, so we use a try/catch PlatformException.
    try {
      result = await _connectivity.checkConnectivity();
    } on PlatformException catch (e) {
      log('Couldn\'t check connectivity status', error: e);
      return;
    }

    // If the widget was removed from the tree while the asynchronous platform
    // message was in flight, we want to discard the reply rather than calling
    // setState to update our non-existent appearance.
    if (!mounted) {
      return Future.value(null);
    }

    return _updateConnectionStatus(result);
  }

  Future<void> _updateConnectionStatus(ConnectivityResult result) async {
    setState(() {
      _connectionStatus = result;
    });
  }

...

_infoTile('Day16 Connection Status:',_connectionStatus.toString()),

執行結果

行動網路

wifi

心得

使用起來可以即時抓取網路的變化狀態也簡單好用