How to get location from service

问题

Somewhat new to android, need some help with services. I have a service which polls for current location at interval X. I want to bind to that service and pass getLastKnownLocation from the service to my Activity A. I am not sure exactly how the information is passed from the bound service to the activity, if its through the binder or what. Anyways, here is my code where I am at thus far.

Service:

public class LocationService extends Service implements LocationListener {


    LocationManager myLocationManager;
    public Location myLocation;
    LocationListener myLocationListener;
    public static final String TAG = LocationService.class.getSimpleName();
    MyDB db;
    double latitude,longitude;
    Cursor c;

    @Override
    public void onCreate() {
        // TODO Auto-generated method stub
        super.onCreate();
        Log.d(TAG, "service started (onCreate)");
        db = new MyDB(getApplicationContext());
        myLocationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);

        Criteria criteria = new Criteria();
        criteria.setPowerRequirement(Criteria.POWER_LOW);
        criteria.setAccuracy(Criteria.ACCURACY_LOW);
        String locationProvider = myLocationManager.getBestProvider(criteria, true);
        myLocationManager.requestLocationUpdates(locationProvider, 1000*60*2, 100, this);
        myLocation = myLocationManager.getLastKnownLocation(locationProvider);


    }
 public class MyBinder extends Binder {
            LocationService getService() {
                return LocationService.this;
            }
        }

Activity A:

public class myActivity extends Activity {
    LocationManager myLocationManager;
    Location myLocation;

    boolean isBound = false;

    private LocationService mBoundService;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);


        bindLocationService();

}
private void bindLocationService() {
        try {
            isBound = getApplicationContext().bindService( new Intent(getApplicationContext(), LocationService.class), mConnection, BIND_AUTO_CREATE );
            bindService(new Intent(this, LocationService.class), mConnection, BIND_AUTO_CREATE);
        } catch (SecurityException e) {
            // TODO: handle exception
        }
    }
private ServiceConnection mConnection = new ServiceConnection() {
        public void onServiceConnected(ComponentName className, IBinder service) {
            mBoundService = ((LocationService.MyBinder)service).getService();
            Log.d(LocationService.TAG, "activity bound to service");

        }

        public void onServiceDisconnected(ComponentName className) {

            mBoundService = null;
            Log.d(LocationService.TAG, "activity unbound to service");
        }
    };
}

回答1:

Send a Broadcast from your service like this:

Intent i = new Intent(NEW_MESSAGE);  
Bundle bundle = new Bundle();
bundle.putString("yourvalue", value);
i.putExtras(bundle);
sendBroadcast(i);

and register for receiver in your activity like this:

newMessage messageReceiver = new newMessage();
registerReceiver(messageReceiver, new IntentFilter(NEW_MESSAGE));

This is your receiver in your activity class:

public class newMessage extends BroadcastReceiver 
{
    @Override
    public void onReceive(Context context, Intent intent) 
    {    
        String action = intent.getAction();
        if(action.equalsIgnoreCase(IMService.NEW_MESSAGE)){    
        Bundle extra = intent.getExtras();
        String username = extra.getString("yourvalue");
    }
}

回答2:

For Communicate between Service and your Activity Create Custom BroadcastReceiver and broadcast it from Service every time when you want to update your Activity with Intent which content new location info.like

    Intent i = new Intent();
    i.setAction(CUSTOM_INTENT);
    context.sendBroadcast(i);

see this example for custom Broadcast

回答3:

You have to "subscribe" your Activity to the Service it binds. The Service can receive an object of type Messenger via the Intent data it receives from the Activity. So you can define a simple Handler inside your Activity and a Messenger that uses it. This way the Service can send objects of type Message to the Activity, shipping all the info you need inside the Message itself.

来源：https://stackoverflow.com/questions/10179470/how-to-get-location-from-service

标签

android

service

location