Question

i have a problem. When i test this. and i ask for the showCurrentLocation function it always returns null. It works in the emulator when i send the location after. But i need this to work on the phone, and there you can’t send the location like in de DDNS window.

Here’s my code

public class LbsGeocodingActivity extends Activity {

private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 1; // in Meters
private static final long MINIMUM_TIME_BETWEEN_UPDATES = 1; // in Milliseconds

protected LocationManager locationManager;

protected Button retrieveLocationButton;
protected Button stopLocationButton;


@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    retrieveLocationButton = (Button) findViewById(R.id.retrieve_location_button);
    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

    locationManager.requestLocationUpdates(
            LocationManager.GPS_PROVIDER, 
            MINIMUM_TIME_BETWEEN_UPDATES, 
            MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
            new MyLocationListener()
    );

    retrieveLocationButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            showCurrentLocation();
        }
    });  
    /*stopLocationButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            //locationManager.removeUpdates(MyLocationListener)  ;          
        }
    }); */ 

}    

public String getMyPhoneNumber(){
    TelephonyManager mTelephonyMgr;
    mTelephonyMgr = (TelephonyManager)
    getSystemService(Context.TELEPHONY_SERVICE); 
    return mTelephonyMgr.getLine1Number();
}

protected void showCurrentLocation() {

    Criteria crit = new Criteria();
    crit.setAccuracy(Criteria.ACCURACY_FINE);
    String provider = locationManager.getBestProvider(crit, true);
    Location loc = locationManager.getLastKnownLocation(provider);


    if (loc != null) {
        String longi = "" + loc.getLongitude();
        String lat = "" + loc.getLatitude();
        String num = getMyPhoneNumber();
        String message = String.format(
                "Current Location \n  Longitude: %1$s \n Latitude: %2$s \n %3$s ",
                longi,
                lat,
                num         );
        Toast.makeText(LbsGeocodingActivity.this, message,
                Toast.LENGTH_LONG).show();
    }
    if (loc == null)Toast.makeText(LbsGeocodingActivity.this, "Null ",
            Toast.LENGTH_LONG).show();
}   

private class MyLocationListener implements LocationListener {



    public void onLocationChanged(Location loc) {
        String longi = "" + loc.getLongitude();
        String lat = "" + loc.getLatitude();
        String num = getMyPhoneNumber();
        String message = String.format(
                "New Location \n Longitude: %1$s \n Latitude: %2$s \n %3$s ",
                longi,
                lat,
                num                 );
        Toast.makeText(LbsGeocodingActivity.this, message, Toast.LENGTH_LONG).show();
    }

    public void onStatusChanged(String s, int i, Bundle b) {
        Toast.makeText(LbsGeocodingActivity.this, "Provider status changed",
                Toast.LENGTH_LONG).show();
    }

    public void onProviderDisabled(String s) {
        Toast.makeText(LbsGeocodingActivity.this,
                "Provider disabled by the user. GPS turned off",
                Toast.LENGTH_LONG).show();
    }

    public void onProviderEnabled(String s) {
        Toast.makeText(LbsGeocodingActivity.this,
                "Provider enabled by the user. GPS turned on",
                Toast.LENGTH_LONG).show();
    }

}

}

My permissions are: FINE_LOCATION COURSE_LOCATION.

I really just want it that it tracks the users location, even on the background..

Answer 1

You can sent mock locations also to your Android device see
Android mock location on device?

Then besides that I had this problem too it seems it maybe never had a location before on your device try to open google maps and make sure you get located and then try again. Also I suspected something like first time you use the application you don’t have access to a last know location yet because you never used it so you first need to get located and next time you startup the application it will work. If you want a quick location try to get located by wifi or cell towers

And make sure the permissions are set!