I have the following code in my Service:
LocationManager locationManager =
(LocationManager) getSystemService(Context.LOCATION_SERVICE);
String provider =
locationManager.getProvider(LocationManager.GPS_PROVIDER).getName();
Location location = locationManager.getLastKnownLocation(provider);
while(true)
{
if(...)//every 5 seconds it gets into
{
....//control if the location is not null
lat = location.getLatitude();
lon = location.getLongitude();
alt = location.getAltitude();
Log.i(TAG, "Latitude: "+lat+"\nLongitude: "+lon+"\nAltitude: "+alt);
}
else {
Log.i(TAG, "Error!");
}
}
This code kind of works in my emulator (GPS are inserted into the Log), but in my Mobile device, this code gets to the else branch. Could somebody tell me where is the problem? In my code or in my Mobile device? Thanks in advance.
P.S.: The GPS is turned on, in another apps it works.
getLastKnownLocation() will not fetch subsequent location from the GPS provider. It will return (as the name may suggest) the last known location requested by some code. I assume that you check location being not null in the condition, which is not shown in your code. The location is null if the device "decided" that the last known location is too old or unreliable by other means. You need to request location updates and provide a location listener to get locations repeatetly.
There are lots of tutorials available. Here ist one. of them.
Related
Is it possible to get the current location of user without using GPS or the internet? I mean with the help of mobile network provider.
What you are looking to do is get the position using the LocationManager.NETWORK_PROVIDER instead of LocationManager.GPS_PROVIDER. The NETWORK_PROVIDER will resolve on the GSM or wifi, which ever available. Obviously with wifi off, GSM will be used. Keep in mind that using the cell network is accurate to basically 500m.
http://developer.android.com/guide/topics/location/obtaining-user-location.html has some really great information and sample code.
After you get done with most of the code in OnCreate(), add this:
// Acquire a reference to the system Location Manager
LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
// Define a listener that responds to location updates
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
// Called when a new location is found by the network location provider.
makeUseOfNewLocation(location);
}
public void onStatusChanged(String provider, int status, Bundle extras) {}
public void onProviderEnabled(String provider) {}
public void onProviderDisabled(String provider) {}
};
// Register the listener with the Location Manager to receive location updates
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
You could also have your activity implement the LocationListener class and thus implement onLocationChanged() in your activity.
By getting the getLastKnownLocation you do not actually initiate a fix yourself.
Be aware that this could start the provider, but if the user has ever gotten a location before, I don't think it will. The docs aren't really too clear on this.
According to the docs getLastKnownLocation:
Returns a Location indicating the data from the last known location
fix obtained from the given provider. This can be done without
starting the provider.
Here is a quick snippet:
import android.content.Context;
import android.location.Location;
import android.location.LocationManager;
import java.util.List;
public class UtilLocation {
public static Location getLastKnownLoaction(boolean enabledProvidersOnly, Context context){
LocationManager manager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
Location utilLocation = null;
List<String> providers = manager.getProviders(enabledProvidersOnly);
for(String provider : providers){
utilLocation = manager.getLastKnownLocation(provider);
if(utilLocation != null) return utilLocation;
}
return null;
}
}
You also have to add new permission to AndroidManifest.xml
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
No, you cannot currently get location without using GPS or internet.
Location techniques based on WiFi, Cellular, or Bluetooth work with the help of a large database that is constantly being updated. A device scans for transmitter IDs and then sends these in a query through the internet to a service such as Google, Apple, or Skyhook. That service responds with a location based on previous wireless surveys from known locations. Without internet access, you have to have a local copy of such a database and keep this up to date. For global usage, this is very impractical.
Theoretically, a mobile provider could provide local data service only but no access to the internet, and then answer location queries from mobile devices. Mobile providers don't do this; no one wants to pay for this kind of restricted data access. If you have data service through your mobile provider, then you have internet access.
In short, using LocationManager.NETWORK_PROVIDER or android.hardware.location.network to get location requires use of the internet.
Using the last known position requires you to have had GPS or internet access very recently. If you just had internet, presumably you can adjust your position or settings to get internet again. If your device has not had GPS or internet access, the last known position feature will not help you.
Without GPS or internet, you could:
Take pictures of the night sky and use the current time to estimate your location based on a star chart. This would probably require additional equipment to ensure that the angles for your pictures are correctly measured.
Use an accelerometer to track location starting from a known position. The accumulation of error in this kind of approach makes it impractical for most situations.
boolean gps_enabled = false;
boolean network_enabled = false;
LocationManager lm = (LocationManager) mCtx
.getSystemService(Context.LOCATION_SERVICE);
gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
network_enabled = lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
Location net_loc = null, gps_loc = null, finalLoc = null;
if (gps_enabled)
gps_loc = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (network_enabled)
net_loc = lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (gps_loc != null && net_loc != null) {
//smaller the number more accurate result will
if (gps_loc.getAccuracy() > net_loc.getAccuracy())
finalLoc = net_loc;
else
finalLoc = gps_loc;
// I used this just to get an idea (if both avail, its upto you which you want to take as I've taken location with more accuracy)
} else {
if (gps_loc != null) {
finalLoc = gps_loc;
} else if (net_loc != null) {
finalLoc = net_loc;
}
}
Here possible to get the User current location Without the use of GPS and Network Provider.
1 . Convert cellLocation to real location (Latitude and Longitude), using "http://www.google.com/glm/mmap"
2.Click Here For Your Reference
Have you take a look Google Maps Geolocation Api? Google Map Geolocation
This is simple RestApi, you just need POST a request, the the service will return a location with accuracy in meters.
It appears that it is possible to track a smart phone without using GPS.
Sources:
Primary: "PinMe: Tracking a Smartphone User around the World"
Secondary: "How to Track a Cellphone Without GPS—or Consent"
I have not yet found a link to the team's final code. When I do I will post, if another has not done so.
You can use TelephonyManager to do that .
I need a little help with some information about LocationManager in Android. I'm using this code to get user's specific information depending on his location,but in My Device Motorola G I get provider="Passive" and also Location return Null My Motorola G is running on Latest Android Kit Kat(4.4) Android Os.
I also try this code in Other Devices so Provider is either Network Or GPS also find Location properly.
locationManager = (LocationManager) getSherlockActivity().getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setAltitudeRequired(true);
criteria.setBearingRequired(true);
criteria.setCostAllowed(true);
criteria.setPowerRequirement(Criteria.POWER_LOW);
provider = locationManager.getBestProvider(criteria, true);
locationManager.requestLocationUpdates(provider, 1000, 0, this);
Location location = locationManager.getLastKnownLocation(provider);
if (location != null) {
System.out.println("Provider " + provider + " has been selected.");
onLocationChanged(location);
} else {
Toast.makeText(getSherlockActivity(), "Location not available", Toast.LENGTH_SHORT).show();
}
I know that this is somehow an old question. But hope my answer will help others as well.
The issue is not related to the used device, actually the issue is how we use the provided API.
In the following code snippet, you pass true for the enabledOnly flag while you just need to pass it as false and it will work correctly at this time.
Instead of :
provider = locationManager.getBestProvider(criteria, true);
To be:
provider = locationManager.getBestProvider(criteria, false);
To clear this point:
If we set this flag "enabledOnly flag" to true, this means to return the requested best provider based on our criteria from the enabled only providers which will return the Passive provider.
While, if we set it to false, this will mean to return the requested best provider based on our criteria even if it is not enabled, which will return gps.
Btw, I am using Moto G too -but it's 2nd Gen- , and it worked with me this way :)
Hope this helps :)
READ THIS IF YOUR APP SUPPORTS kITKAT(4.4) VERSION OF ANDROID
I was having the same issue and my code was working perfectly in other devices not running kitkat,after a little bit of snooping around i found out that you have to explicitly turn on GPS to get location through wifi/gps. you can read about it here.
https://support.google.com/nexus/answer/3467281
I have a Location Manager:
private LocationManager lm;
I initialize it like this:
lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
Then i need last known location which i achieve this way:
if(gpsEnabled)
{
lastKnownLoc = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
}
else if(networkEnabled)
{
lastKnownLoc = lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
}
Now i just want the gps icon in the status bar to disappear, above all, i want it to stop checking my position.
Since i never ask for an update, nor i have a LocationListener in my code i don't know how to do it.
getLastKnownLocation() doesn't turn on the Gps, and no ongoing process is started from that call.
As for the GPS status bar icon, it's controlled by the Android system to inform the user that his location has just been obtained, and you can't hide it.
I am unable to getLastKnownLocations on my Android device (Samsung Galaxy Note N7000) as it is always null, towers is detected as network so it is fine, anybody got any idea how to get my location?
d = getResources().getDrawable(R.drawable.songs_gray);
//Placing pinpoint at location
lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria crit = new Criteria();
towers = lm.getBestProvider(crit, false);
Toast.makeText(LocationActivity.this, "Towers: " + towers, Toast.LENGTH_SHORT).show();
Location location = lm.getLastKnownLocation(towers);
Toast.makeText(LocationActivity.this, "Location: " + location, Toast.LENGTH_SHORT).show();
if(location !=null){
lat = (int) (location.getLatitude()*1E6);
longi = (int) (location.getLongitude()*1E6);
GeoPoint ourLocation = new GeoPoint(lat, longi);
OverlayItem overlayItem = new OverlayItem(ourLocation, "What's up", "2nd String");
CustomPinpoint custom = new CustomPinpoint(d, LocationActivity.this);
custom.insertPinPoint(overlayItem);
overlayList.add(custom);
}else{
Toast.makeText(LocationActivity.this, "Couldn't get provider", Toast.LENGTH_SHORT).show();
}
Manifest
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" />
With getLastKnownLocation() you can only get a Location object when the specified location provider is active.
The documentation says:
Returns a Location indicating the data from the last known location
fix obtained from the given provider. This can be done without
starting the provider. Note that this location could be out-of-date,
for example if the device was turned off and moved to another
location.
If the provider is currently disabled, null is returned.
To detect the current position and not the last detected one you need to enable the location provider(s). This tutorial should help you to understand how to work with location providers as GPS and network.
the last known location is only available if the location has been determined by another app prior to your call. start maps or some other app and let it get a location lock. then run your app.
if you really need location in your app, you need to fall back to some other method, because you cannot depend on there being a last known location.
as a side note, ACCESS_MOCK_LOCATION isn't required here. from the docs,
Allows an application to create mock location providers for testing
Nevermind found out my problem! Just needed to on Google's Location Services on my phone
I have this bit of code;
lm = (LocationManager)
getSystemService(Context.LOCATION_SERVICE);
gpslocation = Double.toString(lm.getLastKnownLocation("gps").getLatitude()) +" "
+ Double.toString(lm.getLastKnownLocation("gps").getLongitude());
Which works fine on both the emulator and my hero running android 1.5, but it Force Closes on the emulator of 1.6 and also on my tattoo.
What changed from 1.5 to 1.6?
OK, using this instead;
lm = (LocationManager)
getSystemService(Context.LOCATION_SERVICE);
Double latPoint = null;
Double lngPoint = null;
Location loc = lm.getLastKnownLocation("gps");
if(loc != null) {
latPoint = lm.getLastKnownLocation("gps").getLatitude();
lngPoint = lm.getLastKnownLocation("gps").getLongitude();
} else {
}
Toast.makeText(getBaseContext(),"test lat " + latPoint, Toast.LENGTH_LONG).show();
I get null toast, and null toast if i fire a location at the emulator before running the app.
In general, use adb logcat, DDMS, or the DDMS perspective in Eclipse to look at the Java stack trace associated with the "force close" dialog, to see what the problem is.
In your case specifically, it will not work because you have not turned on GPS in the code snippet.
You cannot reliably call getLastKnownLocation() on a provider unless that provider has been up and running. In your case, GPS is probably not running, and getLastKnownLocation() will return null.
You will need to register for location updates or proximity alerts, to get the GPS radio powered on and seeking fixes, before getLastKnownLocation() will work. Also, with the emulator, you will need to submit a fix (e.g., via DDMS) after registering for location updates or something before getLastKnownLocation() will return a non-null value.