android - 关闭应用程序时，Android广播接收器无法在服务中工作

Question

我正在使用服务来管理 wifi 网络状态。只要应用程序正在运行，它几乎可以正常工作。但是当应用程序关闭时，服务中的广播接收器不起作用。

public class WifiService extends Service {

private class WifiReceiver extends BroadcastReceiver{
    String wifiNameN;
    int wifiIdN;
    @Override
    public void onReceive(Context context, Intent intent) {
        if(WifiManager.NETWORK_STATE_CHANGED_ACTION.equals(intent.getAction())) {

            NetworkInfo netInfo = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
            assert netInfo != null;
            Log.i("SerSC","=State"+wifiName);
            Log.i("SerSC","=State"+wifiId);

            if(netInfo.getDetailedState().equals(NetworkInfo.DetailedState.CONNECTED)) {

                Log.i("SerSC","=Connection");

            } else if(netInfo.getDetailedState().equals(NetworkInfo.DetailedState.CONNECTING)) {

            } else if(netInfo.getDetailedState().equals(NetworkInfo.DetailedState.DISCONNECTING)) {

                WifiManager wifiManager = (WifiManager) context.getApplicationContext().getSystemService(Context.WIFI_SERVICE);
                assert wifiManager != null;
                WifiInfo wifiInfo = wifiManager.getConnectionInfo();
                wifiInfo.getSSID();
                wifiNameN = netInfo.getExtraInfo();
                Log.i("SerSC","=D"+wifiNameN+"---"+wifiIdN);
                wifiIdN = wifiInfo.getIpAddress();

            } else if(netInfo.getDetailedState().equals(NetworkInfo.DetailedState.DISCONNECTED)) {

                if (wifiName.equals(wifiNameN) && wifiId == wifiIdN) {
                    Log.i("SerSC","=DC"+wifiNameN+"---"+wifiIdN);
                    Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
                    // Vibrate for 5000 milliseconds
                    assert v != null;
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                        v.vibrate(VibrationEffect.createOneShot(1000, VibrationEffect.DEFAULT_AMPLITUDE));
                    } else {
                        //deprecated in API 26
                        v.vibrate(1000);
                    }
                    // I want to show a notification on system window e.g like messenger chat head appears when message comes
                }

            }
        }
    }
}

private String wifiName;
private int wifiId;

@Nullable
@Override
public IBinder onBind(Intent intent) {
    return null;
}

@Override
public void onCreate() {
    super.onCreate();
    IntentFilter filter = new IntentFilter();
    filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
    registerReceiver(new WifiReceiver(), filter);
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    Log.i("SerSC", "Service Started");
    if (intent != null) {
        wifiName = intent.getStringExtra(MainActivity.WIFI_NAME_TAG);
        wifiId = intent.getIntExtra(MainActivity.WIFI_NETWORK_TAG, -1);
    }
    return START_STICKY;
}

@Override
public void onDestroy() {
    super.onDestroy();
    Log.i("SerSC","Service Destroyed");
    unregisterReceiver(new WifiReceiver());
}

}

这种情况也有效

if(netInfo.getDetailedState().equals(NetworkInfo.DetailedState.CONNECTED)) {

            Log.i("SerSC","=Connection");

        }

但是当我关闭 WIFI 设备时，NetworkInfo.DetailedState.DISCONNECTING 和 DISCONNECTED 不起作用。我想在后台永久运行服务并收听网络状态，即使应用程序没有运行。请不要提供链接。如果您决心帮助我，请编写代码

标签： androidservicebroadcastreceiverbackground-processwifimanager