Android:互联网连接改变监听器

Question

我已经有了这个代码来监听连接变化 -

public class NetworkStateReceiver extends BroadcastReceiver
{
  public void onReceive(Context context, Intent intent)
  {
    Log.d("app","Network connectivity change");

    if(intent.getExtras() != null)
    {
      NetworkInfo ni = (NetworkInfo) intent.getExtras().get(ConnectivityManager.EXTRA_NETWORK_INFO);
      if(ni != null && ni.getState() == NetworkInfo.State.CONNECTED)
      {
        Log.i("app", "Network " + ni.getTypeName() + " connected");
      }
    }

    if(intent.getExtras().getBoolean(ConnectivityManager.EXTRA_NO_CONNECTIVITY, Boolean.FALSE))
    {
      Log.d("app", "There's no network connectivity");
    }
  }
}

我使用此代码检查Internet连接 - Internet Check

但问题是,如果网络在没有任何连接变化的情况下突然失去互联网连接,则此代码无用.有没有办法为Internet连接更改创建Broadcast Receiver侦听器？我有一个Web应用程序,突然的Internet连接更改可能会导致问题.

Answer 1

试试这个

public class NetworkUtil {
    public static final int TYPE_WIFI = 1;
    public static final int TYPE_MOBILE = 2;
    public static final int TYPE_NOT_CONNECTED = 0;
    public static final int NETWORK_STATUS_NOT_CONNECTED = 0;
    public static final int NETWORK_STATUS_WIFI = 1;
    public static final int NETWORK_STATUS_MOBILE = 2;

    public static int getConnectivityStatus(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
        if (null != activeNetwork) {
            if(activeNetwork.getType() == ConnectivityManager.TYPE_WIFI)
                return TYPE_WIFI;

            if(activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE)
                return TYPE_MOBILE;
        } 
        return TYPE_NOT_CONNECTED;
    }

    public static int getConnectivityStatusString(Context context) {
        int conn = NetworkUtil.getConnectivityStatus(context);
        int status = 0;
        if (conn == NetworkUtil.TYPE_WIFI) {
            status = NETWORK_STATUS_WIFI;
        } else if (conn == NetworkUtil.TYPE_MOBILE) {
            status = NETWORK_STATUS_MOBILE;
        } else if (conn == NetworkUtil.TYPE_NOT_CONNECTED) {
            status = NETWORK_STATUS_NOT_CONNECTED;
        }
        return status;
    }
}

而对于BroadcastReceiver

public class NetworkChangeReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(final Context context, final Intent intent) {

        int status = NetworkUtil.getConnectivityStatusString(context);
        Log.e("Sulod sa network reciever", "Sulod sa network reciever");
        if ("android.net.conn.CONNECTIVITY_CHANGE".equals(intent.getAction())) {
            if (status == NetworkUtil.NETWORK_STATUS_NOT_CONNECTED) {
                new ForceExitPause(context).execute();
            } else {
                new ResumeForceExitPause(context).execute();
            }
       }
    }
}

不要忘记将它放入AndroidManifest.xml中

 <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 <uses-permission android:name="android.permission.INTERNET" />
 <receiver
        android:name="NetworkChangeReceiver"
        android:label="NetworkChangeReceiver" >
        <intent-filter>
            <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
            <action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
        </intent-filter>
    </receiver>

希望这会帮助你干杯!

Answer 2

这是使用registerDefaultNetworkCallback（和registerNetworkCallbackAPI < 24）的 Java 代码：

ConnectivityManager.NetworkCallback networkCallback = new ConnectivityManager.NetworkCallback() {
    @Override
    public void onAvailable(Network network) {
        // network available
    }

    @Override
    public void onLost(Network network) {
        // network unavailable
    }
};

ConnectivityManager connectivityManager =
        (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
    connectivityManager.registerDefaultNetworkCallback(networkCallback);
} else {
    NetworkRequest request = new NetworkRequest.Builder()
            .addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET).build();
    connectivityManager.registerNetworkCallback(request, networkCallback);
}

Answer 3

更新:

针对Android 7.0(API级别24)及更高版本的应用如果在其清单中声明广播接收器,则不会收到CONNECTIVITY_ACTION广播.如果应用程序使用Context.registerReceiver()注册其BroadcastReceiver并且该上下文仍然有效,它们仍将接收CONNECTIVITY_ACTION广播.

您需要通过以下registerReceiver()方法注册接收器:

 IntentFilter intentFilter = new IntentFilter("android.net.conn.CONNECTIVITY_CHANGE");
 mCtx.registerReceiver(new NetworkBroadcastReceiver(), intentFilter);

Answer 4

api 28+中已弃用 ConnectivityAction 。相反registerDefaultNetworkCallback，只要支持api 24+，就可以使用。

在科特林：

val connectivityManager = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
connectivityManager?.let {
    it.registerDefaultNetworkCallback(object : ConnectivityManager.NetworkCallback() {
        override fun onAvailable(network: Network) {
            //take action when network connection is gained
        }
        override fun onLost(network: Network?) {
            //take action when network connection is lost
        }
    })
}

Answer 5

这应该工作:

public class ConnectivityChangeActivity extends Activity {

    private BroadcastReceiver networkChangeReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            Log.d("app","Network connectivity change");
        }
    };

    @Override
    protected void onResume() {
        super.onResume();

        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
        registerReceiver(networkChangeReceiver, intentFilter);
    }

    @Override
    protected void onPause() {
        super.onPause();

        unregisterReceiver(networkChangeReceiver);
    }
}

Answer 6

我将此方法用作连接侦听器。为 Lolipop+ 工作，Android JAVA 语言。

if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP){
    ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkRequest networkRequest = new NetworkRequest.Builder().build();
    connectivityManager.registerNetworkCallback(networkRequest, new ConnectivityManager.NetworkCallback() {
        @Override
        public void onAvailable(Network network) {
            super.onAvailable(network);
            Log.i("Tag", "active connection");
        }

        @Override
        public void onLost(Network network) {
            super.onLost(network);
            Log.i("Tag", "losing active connection");
            isNetworkConnected();
        }
    });
}

private boolean isNetworkConnected() {
    ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    if (!(cm.getActiveNetworkInfo() != null && cm.getActiveNetworkInfo().isConnected())) {
        //Do something
        return false;
    }
    return true;
}

并在您的 Android Manifest.xml 中添加此权限

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

Answer 7

在我的自定义视图模型中，我观察到网络状态变化如下：

public class MyViewModel extends AndroidViewModel {
    private final MutableLiveData<Boolean> mConnected = new MutableLiveData<>();

    public MyViewModel(Application app) {
        super(app);

        ConnectivityManager manager = (ConnectivityManager)app.getSystemService(Context.CONNECTIVITY_SERVICE);

        if (manager == null || Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
            mConnected.setValue(true);
            return;
        }

        NetworkRequest networkRequest = new NetworkRequest.Builder()
            .addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
            .addTransportType(NetworkCapabilities.TRANSPORT_CELLULAR)
            .addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
            .build();

        manager.registerNetworkCallback(networkRequest, new ConnectivityManager.NetworkCallback() {
            Set<Network> availableNetworks = new HashSet<>();

            public void onAvailable(@NonNull Network network) {
                availableNetworks.add(network);
                mConnected.postValue(!availableNetworks.isEmpty());
            }

            public void onLost(@NonNull Network network) {
                availableNetworks.remove(network);
                mConnected.postValue(!availableNetworks.isEmpty());
            }

            public void onUnavailable() {
                availableNetworks.clear();
                mConnected.postValue(!availableNetworks.isEmpty());
            }
        });
    }

    @NonNull
    public MutableLiveData<Boolean> getConnected() {
        return mConnected;
    }
}

然后在我的 Activity 或 Fragment 中，我可以通过观察来更改 UI：

@Override
protected void onCreate(Bundle savedInstanceState) {
    MyViewModel vm = new ViewModelProvider(this).get(MyViewModel.class);

    vm.getConnected().observe(this, connected -> {
        // TODO change GUI depending on the connected value
    });
}