Android位置更新作为后台服务

Question

i am new to android and working on an app to achieve the functionality of getting my location updates even if the application is quit.ie it should keep updating my current location in the server irrespective of the state of my application- active of terminated.

can you guys suggest me as to what approach should i follow for the same ?? Would really appreciate your help...

Answer 1

Here is the code to get user's location every X mins or every X meters using a handler.

Location gpslocation = null;

    private static final int GPS_TIME_INTERVAL = 60000; // get gps location every 1 min
    private static final int GPS_DISTANCE= 1000; // set the distance value in meter

    /*
       for frequently getting current position then above object value set to 0 for both you will get continues location but it drown the battery
    */

    private void obtainLocation(){
    if(locMan==null)
        locMan = (LocationManager) getSystemService(LOCATION_SERVICE);

        if(locMan.isProviderEnabled(LocationManager.GPS_PROVIDER)){
            gpslocation = locMan.getLastKnownLocation(LocationManager.GPS_PROVIDER);
            if(isLocationListener){
                 locMan.requestLocationUpdates(LocationManager.GPS_PROVIDER, 
                            GPS_TIME_INTERVAL, GPS_DISTANCE, GPSListener);
                    }
                }
            }
    }

Handler

    private static final int HANDLER_DELAY = 1000*60*5;

    Handler handler = new Handler();
    handler.postDelayed(new Runnable() {
            public void run() {
                myLocation = obtainLocation();
                handler.postDelayed(this, HANDLER_DELAY);
            }
        }, START_HANDLER_DELAY);

GPS LocationListener

private LocationListener GPSListener = new LocationListener(){
    public void onLocationChanged(Location location) {
        // update your location

    }

    public void onProviderDisabled(String provider) {
    }

    public void onProviderEnabled(String provider) {
    }

    public void onStatusChanged(String provider, int status, Bundle extras) {
    }
};

Answer 2

This is the code for updating the latitude and longitude of device in a background service and will always work in a background. The service will never stops if stopped by someone(mannually or system) it will restart automatically.

    public class LocationService extends Service implements LocationListener {

        LocationManager m_locationManager;

        @Override
        public void onCreate() {

            this.m_locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);

              Toast.makeText(getApplicationContext(), "Location Service starts", Toast.LENGTH_SHORT).show();

        }



        @Override
        public int onStartCommand(Intent intent, int flags, int startId) {
            //TODO do something useful
            Toast.makeText(getApplicationContext(), "Service starts", Toast.LENGTH_SHORT).show();



            //  Here I offer two options: either you are using satellites or the Wi-Fi services to get user's location
            //  this.m_locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 3000, 0, this); //  User's location is retrieve every 3 seconds
            this.m_locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);

            this.m_locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 1, this);
        return START_STICKY;
        }


        @Override
        public IBinder onBind(Intent intent) {
            //TODO for communication return IBinder implementation
            return null;
        }


        @Override
        public void onDestroy() {
            super.onDestroy();
            Toast.makeText(getApplicationContext(), "Service Task destroyed", Toast.LENGTH_LONG).show();
            Intent myIntent = new Intent(getApplicationContext(), LocationService.class);

            PendingIntent pendingIntent = PendingIntent.getService(getApplicationContext(), 0, myIntent, 0);

            AlarmManager alarmManager1 = (AlarmManager) getSystemService(ALARM_SERVICE);

            Calendar calendar = Calendar.getInstance();

            calendar.setTimeInMillis(System.currentTimeMillis());

            calendar.add(Calendar.SECOND, 10);

            alarmManager1.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);

            Toast.makeText(getApplicationContext(), "Start Alarm", Toast.LENGTH_SHORT).show();
        }



        @Override
        public void onTaskRemoved(Intent rootIntent) {
            super.onTaskRemoved(rootIntent);
                Intent myIntent = new Intent(getApplicationContext(), LocationService.class);

                PendingIntent pendingIntent = PendingIntent.getService(getApplicationContext(), 0, myIntent, 0);

                AlarmManager alarmManager1 = (AlarmManager) getSystemService(ALARM_SERVICE);

                Calendar calendar = Calendar.getInstance();

                calendar.setTimeInMillis(System.currentTimeMillis());

                calendar.add(Calendar.SECOND, 10);

                alarmManager1.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);

                Toast.makeText(getApplicationContext(), "Start Alarm", Toast.LENGTH_SHORT).show();



        }


        @Override
        public void onLocationChanged(Location loc) {
            if (loc == null)    //  Filtering out null values
                return ;

            Double lat = loc.getLatitude();
            Double lon = loc.getLongitude();
    //        Toast.makeText(getApplicationContext(),"Latitude = "+lat+ "\nLongitude = "+lon, Toast.LENGTH_SHORT).show();

        //    new UpdateLatitudeLongitude(LocationService.this, lat, lon,).execute();

//Calling AsyncTask for upload latitude and longitude
        }

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {

        }

        @Override
        public void onProviderEnabled(String provider) {

        }

        @Override
        public void onProviderDisabled(String provider) {

        }






        }