Android get location from GPS

Question

My situation is like that the user has their tablet with them all day and its gps or location can be turned off whole time to save battery, and then wanna post something using my application which requires them to turn on the location and then upon posting I wanna get the latitude and longitude of the device. Using LocationManager when I get the location its null. Any help would be appreciated.

I'm using the below code to get the location:

LocationManager lm = (LocationManager)ctx.getSystemService(Context.LOCATION_SERVICE); 
Location location = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);

As I've checked around, it seems I have to put a listenere to update the device location so when I get the last known location it wouldn't be null, but how can I do that if the device's location is off before using the application? I wanna get the location where the user is posting using the application.

EDIT: I've changed my code to below, but loc is always null and loc2 always returns location. why is that?

locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
Location loc = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
Location loc2 = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

and this is the listener:

LocationListener locationListener = new LocationListener() {
    public void onLocationChanged(Location location) {

    }

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

    }

    public void onProviderEnabled(String provider) {

    }

    public void onProviderDisabled(String provider) {

    }
};

score 1 · Accepted Answer · edited May 23 '17 at 10:27

1

You might want to consider using Network Location as well as GPS Location, as many users just keep the GPS radio off to conserve battery. With Location Services set in "Battery Saving" mode, the device can get accurate geo-location data using Wi-Fi if available.
If you use Network Location data as well as GPS radio data, you would have a much better chance of getting location data when you need it.

However, if Location Services were disabled completely prior to being turned on in order to post something using your app, then you would need to register a Location Listener to get the first instance of location data.

Take a look at this post to see how to use both Network and GPS Location: Android Location Manager, Get GPS location ,if no GPS then get to Network Provider location

edited May 23 '17 at 10:27

Community

1
1

answered Mar 14 '15 at 19:44

Daniel Nugent

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Thanks Daniel, in my case the user is a visitor, visiting shops so they know how the system works, the device is used for this situation and they use 3G to send data, so basically the wi-fi is off the table but 3g should be available upon posting. – arash moeen Mar 15 '15 at 09:34
Daniel please check my Edit – arash moeen Mar 15 '15 at 10:18

score 0 · Answer 2 · answered Mar 20 '15 at 05:30

GPS rarely works indoors. If your users are "visiting shops" then it makes sense the GPS provider will never return a valid location as there is no GPS signal available indoors.

The network provider uses both Wifi and cell towers, so as long as they at least have cell service, you should return a location. That explains why you are always able to retrieve a location update with the network provider.

I would recommend you look into the Fused Provider which is the newest Location API released by Google. This API will automatically handle switching between GPS, network, and passive location listeners for you based on both what settings the user has enabled and which provider gives the best data given the users situation.

Well thanks ori-k, I already implemented the system using both GPS and NETWORK though most of the times only network works properly. — arash moeen, Mar 20 '15 at 21:29

Android get location from GPS

2 Answers2