Continuous location updates in background

问题

i am developing a application which will send location updates continuously from a background service. i tried following code.

public class LocationService extends Service implements LocationListener,
GooglePlayServicesClient.ConnectionCallbacks,
GooglePlayServicesClient.OnConnectionFailedListener {
    LocationRequest mLocationRequest;
    LocationClient mLocationClient;
    @Override
     public void onCreate() {
     //creating log file in mobile
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Service created:", com.example.locationservice.Constants.LOG_FILE);

      mLocationRequest = LocationRequest.create();
      mLocationRequest.setInterval(5*1000);
      mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    //  mLocationRequest.setFastestInterval(5*1000);
      mLocationClient = new LocationClient(getApplicationContext(), this,this);
      mLocationClient.connect();

     }
    @Override
     public void onStart(Intent intent, int startId) {
      int start = Service.START_STICKY;
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Service Started:", com.example.locationservice.Constants.LOG_FILE);

     }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        // TODO Auto-generated method stub
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Connection to client failed", com.example.locationservice.Constants.LOG_FILE);
        this.stopSelf();

    }

    @Override
    public void onConnected(Bundle arg0) {
        // TODO Auto-generated method stub
        Log.i("info", "Location Client is Connected");
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Location Client Connectd:", com.example.locationservice.Constants.LOG_FILE);
        //checking for locaton enabled or not
        if(Util.isLocationEnabled(getApplicationContext())){
        //checking for internet available or not
            if(Util.isInternetOn(getApplicationContext())){
                mLocationClient.requestLocationUpdates(mLocationRequest, this);
            }else{
              Log.i("info", "Internet not available");
                appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Internet not available", com.example.locationservice.Constants.LOG_FILE);
                this.stopSelf();
            }
          }else{
            Log.i("info", "Location Acess disabled");
            appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Location Acess disabled", com.example.locationservice.Constants.LOG_FILE);
            this.stopSelf();
          }
          Log.i("info", "Service Connect status :: " + isServicesConnected());

    }

    @Override
    public void onDisconnected() {
        // TODO Auto-generated method stub
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Location Client DisConnectd:", com.example.locationservice.Constants.LOG_FILE);
        Log.i("info", "Location Client is DisConnected");

    }

    @Override
    public void onLocationChanged(Location location) {
        // TODO Auto-generated method stub
        double latitude = location.getLatitude();
          double longitude = location.getLongitude();
            appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Location Changed:", com.example.locationservice.Constants.LOG_FILE);
          Log.i("info", "Latitude :: " + latitude);
          Log.i("info", "Longitude :: " + longitude);
          if(Util.isInternetOn(getApplicationContext())){
          //sending location details
          sendLocation(location);
          }else{
              this.stopSelf();
              Log.i("info", "Internet not available");
                appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Internet not available", com.example.locationservice.Constants.LOG_FILE);
          }
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
     public void onDestroy() {
      // TODO Auto-generated method stub
      Log.i("info", "Service is destroyed");
      mLocationClient.removeLocationUpdates(this);  
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Service Destroyed:", com.example.locationservice.Constants.LOG_FILE);
      super.onDestroy();
     }
    private boolean isServicesConnected() {
          // Check that Google Play services is available
          int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(LocationService.this);
          // If Google Play services is available
          if (ConnectionResult.SUCCESS == resultCode) {           
           return true;
          } else {
           return false;
          }
         }
}

but onLocationChanged is calling only when i opend the inbuilt map application. other wise it is not updating the location details. i started this service from a activity using alarm service. alarmManager triggers for every one minute. can any one tell me why onLocationChanged is not calling continuously.

Thanks in advance.

回答1:

Try this:

@Override
 public void onCreate() {
 //creating log file in mobile
    appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Service created:", com.example.locationservice.Constants.LOG_FILE);

  mLocationClient = new LocationClient(getApplicationContext(), this,this);
 }

replace your onStart with:

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
mLocationClient.connect();
}

and:

@Override
public void onConnected(Bundle arg0) {
mLocationRequest = LocationRequest.create();
mLocationRequest.setInterval(5*1000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
mLocationClient.requestLocationUpdates(mLocationRequest, this);
}

Invoke your service:

startService(yourServiceIntent);

You can also check my code here

回答2:

Is it working fine in background? Service does not stops after 45 mins while running in the background ? – Noman Nov 3 '15 at 6:18

It's a good comment. I had some proglem with the location update long continious in my project. And it really stopped after 45 minutes.

My service is foreground. I using

StartForeground(ServicesId.Push, notification);

And I every 45 minutes wake up location update

_timer = new Timer(); _timer.Schedule(new TimerTaskTrek(this), 45 * 60 * 1000 + 10 * 1000, 45 * 60 * 1000 + 10 * 1000);

And In timerTask

try {

Looper.Prepare();

} catch (Exception e) {

}

_client = new >GoogleApiClient.Builder(this).AddApi(LocationServices.API) .AddConnectionCallbacks(this) .AddOnConnectionFailedListener(this) .Build();

_client.Connect();

It's very simple and it's work very good. Enjoy

来源：https://stackoverflow.com/questions/21726670/continuous-location-updates-in-background