libathos libathos - 3 months ago 27
Android Question

My GPS provider is enabled but I get null location nonetheless

I'm using this code to get the geo-position of the user

public Location getLocation() {

Location location = null;
double lat;
double lng;
try {
LocationManager mLocationManager = (LocationManager) con.getSystemService(LOCATION_SERVICE);

// getting GPS status
boolean isGPSEnabled = mLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);

// getting network status
boolean isNetworkEnabled = mLocationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);


if (!isGPSEnabled && !isNetworkEnabled) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(intent);
} else {
// First get location from Network Provider
if (isNetworkEnabled) {
mLocationManager.requestLocationUpdates( LocationManager.NETWORK_PROVIDER, 0, 0, this);
Log.d("Network", "Network");
if (mLocationManager != null) {
location = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
lat = location.getLatitude();
lng = location.getLongitude();
System.out.println(lat);
}
}
}
//get the location by gps
if (isGPSEnabled) {
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0, this);
Log.d("GPS Enabled", "GPS Enabled");
if (mLocationManager != null) {
location = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
lat = location.getLatitude();
lng = location.getLongitude();
System.out.println(lat);
}
}
}
}

} catch (Exception e) {
e.printStackTrace();
}



return location;
}


An this is what I get:

Network
39.68967
Gps Enabled
(nothing)

I can't understand the reason why Gps is enabled and I still can't get the coordinates from the gps provider

Answer

I just finished creating a sample project for understanding the usage of Location Services. I am just posting my code, feel free to use it for your need and understanding the working of Location Services.

public class DSLVFragmentClicks extends Activity implements LocationListener {
private final int BESTAVAILABLEPROVIDERCODE = 1;
private final int BESTPROVIDERCODE = 2;
LocationManager locationManager;
String bestProvider;
String bestAvailableProvider;

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == BESTPROVIDERCODE) {
        if (resultCode!= Activity.RESULT_OK || locationManager.isProviderEnabled(bestProvider)) {
            Toast.makeText(getActivity(), "Error! Location Service " + bestProvider + " not Enabled", Toast.LENGTH_LONG).show();

        } else {
            getLocation(bestProvider);
        }
    } else {
        if (resultCode!= Activity.RESULT_OK || locationManager.isProviderEnabled(bestAvailableProvider)) {
            Toast.makeText(getActivity(), "Error! Location Service " + bestAvailableProvider + " not Enabled", Toast.LENGTH_LONG).show();

        } else {
            getLocation(bestAvailableProvider);
        }
    }
}

public void getLocation(String usedLocationService) {
    Toast.makeText(getActivity(), "getting Location", Toast.LENGTH_SHORT).show();
    long updateTime = 0;
    float updateDistance = 0;
    // finding the current location 
    locationManager.requestLocationUpdates(usedLocationService, updateTime, updateDistance, this);

}


@Override
public void onCreate(Bundle savedState) {
    super.onCreate(savedState);
    setContentView(R.layout.main);
    // set a Criteria specifying things you want from a particular Location Service
            Criteria criteria = new Criteria();
            criteria.setSpeedRequired(false);
            criteria.setAccuracy(Criteria.ACCURACY_FINE);
            criteria.setCostAllowed(true);
            criteria.setBearingAccuracy(Criteria.ACCURACY_HIGH);
            criteria.setAltitudeRequired(false);

            locationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);
            // finding best provider without fulfilling the criteria
            bestProvider = locationManager.getBestProvider(criteria, false);
            // finding best provider which fulfills the criteria
            bestAvailableProvider = locationManager.getBestProvider(criteria, true);
            String toastMessage = null;
            if (bestProvider == null) {
                toastMessage = "NO best Provider Found";
            } else if (bestAvailableProvider != null && bestAvailableProvider.equals(bestAvailableProvider)) {
                boolean enabled = locationManager.isProviderEnabled(bestAvailableProvider);
                if (!enabled) {
                    Toast.makeText(getActivity(), " Please enable " + bestAvailableProvider + " to find your location", Toast.LENGTH_LONG).show();
                    Intent mainIntent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                    startActivityForResult(mainIntent, BESTAVAILABLEPROVIDERCODE);
                } else {
                    getLocation(bestAvailableProvider);
                }
                toastMessage = bestAvailableProvider + " used for getting your current location";
            } else {
                boolean enabled = locationManager.isProviderEnabled(bestProvider);
                if (!enabled) {
                    Toast.makeText(getActivity(), " Please enable " + bestProvider + " to find your location", Toast.LENGTH_LONG).show();
                    Intent mainIntent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                    startActivityForResult(mainIntent, BESTPROVIDERCODE);
                } else {
                    getLocation(bestProvider);
                }
                toastMessage = bestProvider + " is used to get your current location";

            }
            Toast.makeText(getActivity(), toastMessage, Toast.LENGTH_LONG).show();
            return true;
        }
    });
}

@Override
public void onLocationChanged(Location location) {
    Log.d("Location Found", location.getLatitude() + " " + location.getLongitude());
    // getting the street address from longitute and latitude
    Geocoder geocoder = new Geocoder(getActivity(), Locale.getDefault());
    String addressString = "not found !!";
    try {
        List<Address> addressList = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 1);
        StringBuilder stringBuilder = new StringBuilder();
        if (addressList.size() > 0) {
            Address address = addressList.get(0);
            for (int i = 0; i < address.getMaxAddressLineIndex(); i++) {
                stringBuilder.append(address.getAddressLine(i)).append("\n");
                stringBuilder.append(address.getLocality()).append("\n");
                stringBuilder.append(address.getPostalCode()).append("\n");
                stringBuilder.append(address.getCountryName()).append("\n");
            }

            addressString = stringBuilder.toString();
            locationManager.removeUpdates(this);
        }
    } catch (IOException e) {
        e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
    }
    Toast.makeText(getActivity(), " Your Location is " + addressString, Toast.LENGTH_LONG).show();
}

@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
    //To change body of implemented methods use File | Settings | File Templates.
}

@Override
public void onProviderEnabled(String s) {
    //To change body of implemented methods use File | Settings | File Templates.
}

@Override
public void onProviderDisabled(String s) {
    //To change body of implemented methods use File | Settings | File Templates.
}
}

If you didn't understand any part of it then feel free to ask.