I am trying to get the current position of the phone, for this I use the GPSTracker tutorial, the problem is always use the method getLastKnownLocation and return older position.
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
You can see the tutorial use getLastKnownLocation when use Network or GPS provider, but I realy realy need the current position.
I dont know how get it!
Use Fused Location Provider APIs in conjunction with GoogleApiClient. You can find the apis here. They are designed to give locations with high accuracy. Use it using GoogleApiClient.
new GoogleApiClient.Builder(context)
.addApi(LocationServices.API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build()
There are other approaches to using location providers. You should not restrict yourself to locations obtained using GPS and Mobile Network. Rather iterate over all the location providers and depending on your accuracy requirement choose those which give you high accuracy. The following code does this:
Location bestResult = null;
float bestAccuracy = Float.MAX_VALUE;
long bestAge = Long.MIN_VALUE;
List<String> matchingProviders = mLocationManager.getAllProviders();
for (String provider : matchingProviders) {
Location location = mLocationManager.getLastKnownLocation(provider);
if (location != null) {
float accuracy = location.getAccuracy();
long time = location.getTime();
if (accuracy < bestAccuracy) {
bestResult = location;
bestAccuracy = accuracy;
bestAge = time;
}
}
}
// Return best reading or null
if (bestAccuracy > minAccuracy
|| (System.currentTimeMillis() - bestAge) > maxAge) {
return null;
} else {
return bestResult;
}
You can also use the location object directly after checking them for accuracy. You should take advantage of the locations accessed by other apps and not just rely on the locations obtained by GPS/Mobile Networks.
If you want to continuously listen to location updates implement the Locationlistener callbacks to continuously get location updates.
Create this class:
public class MyLocation{
Timer timer1;
LocationManager lm;
LocationResult locationResult;
boolean gps_enabled=false;
boolean network_enabled=false;
public boolean getLocation(Context context, LocationResult result)
{
//I use LocationResult callback class to pass location value from MyLocation to user code.
locationResult=result;
if(lm==null)
lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
//exceptions will be thrown if provider is not permitted.
try{gps_enabled=lm.isProviderEnabled(LocationManager.GPS_PROVIDER);}catch(Exception ex){}
try{network_enabled=lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);}catch(Exception ex){}
//don't start listeners if no provider is enabled
if(!gps_enabled && !network_enabled)
return false;
if(gps_enabled)
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps);
if(network_enabled)
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
timer1=new Timer();
timer1.schedule(new GetLastLocation(), 20000);
return true;
}
LocationListener locationListenerGps = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerNetwork);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerGps);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
class GetLastLocation extends TimerTask {
@Override
public void run() {
lm.removeUpdates(locationListenerGps);
lm.removeUpdates(locationListenerNetwork);
Location net_loc=null, gps_loc=null;
if(gps_enabled)
gps_loc=lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(network_enabled)
net_loc=lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
//if there are both values use the latest one
if(gps_loc!=null && net_loc!=null){
if(gps_loc.getTime()>net_loc.getTime())
locationResult.gotLocation(gps_loc);
else
locationResult.gotLocation(net_loc);
return;
}
if(gps_loc!=null){
locationResult.gotLocation(gps_loc);
return;
}
if(net_loc!=null){
locationResult.gotLocation(net_loc);
return;
}
locationResult.gotLocation(null);
}
}
public static abstract class LocationResult{
public abstract void gotLocation(Location location);
}
}
Now put this in your activity code
LocationResult locationResult = new LocationResult() {
@Override
public void gotLocation(Location location) {
Log.d(tag, "lon: "+location.getLongitude()+" ----- lat: "+location.getLatitude());
}
};
At last call it
MyLocation myLocation = new MyLocation();
myLocation.getLocation(context, locationResult);
And you are done.
If I recall correctly, that tutorial is rather old and do not use fused locations. In case you develop in Android Studio, consider trying this library: https://github.com/mcharmas/Android-ReactiveLocation
Way less code and fused location using the latest API.
To get the last known location simply:
ReactiveLocationProvider locationProvider = new ReactiveLocationProvider(context);
locationProvider.getLastKnownLocation()
.subscribe(new Action1<Location>() {
@Override
public void call(Location location) {
// doSthImportantWithObtainedLocation(location);
}
});
Thats it!
I think one of the answeres used the locationListner, but here is a simple solution that will return the location even if GPS is not available by calling get getBestProvider,
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
criteria.setCostAllowed(true);
criteria.setPowerRequirement(Criteria.POWER_LOW);
String context = Context.LOCATION_SERVICE;
locationManager = (LocationManager)getSystemService(context);
String provider = locationManager.getBestProvider(criteria, true);
locationManager.requestLocationUpdates(provider, 2000, 0, locationListener);
private final LocationListener locationListener = new LocationListener()
{
public void onLocationChanged(Location location)
{
Double latitude = location.getLatitude();
Double longitude = location.getLongitude();
}
};
The method mentioned above is the deprecated method and Android has asked developers to use the below method.
https://developer.android.com/training/location/retrieve-current.html
Sample Code
onCreate(){
final LocationManager manager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
if (!manager.isProviderEnabled(LocationManager.GPS_PROVIDER) && !manager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)) {
buildAlertMessageNoGps();
}
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(LocationServices.API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
@Override
protected void onStart() {
super.onStart();
// Connect the client.
mGoogleApiClient.connect();
}
@Override
protected void onStop() {
// Disconnecting the client invalidates it.
mGoogleApiClient.disconnect();
super.onStop();
}
@Override
public void onConnected(Bundle bundle) {
mLocationRequest = LocationRequest.create();
mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
mLocationRequest.setInterval(1000 * 60 * 5);
LocationServices.FusedLocationApi.requestLocationUpdates(
mGoogleApiClient, mLocationRequest, this);
}
@Override
public void onLocationChanged(Location location) {
Geocoder geocoder;
List<Address> addresses;
geocoder = new Geocoder(this, Locale.getDefault());
try {
addresses = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 1);
String address = addresses.get(0).getAddressLine(1);
} catch (IOException e) {
e.printStackTrace();
}
editor.commit();
}
Use below code -
private class LocationListener extends Activity implements android.location.LocationListener{
Location mLastLocation;
public LocationListener(String provider){
Log.e(TAG, "LocationListener " + provider);
mLastLocation = new Location(provider);
}
LocationListener[] mLocationListeners = new LocationListener[] {
new LocationListener(LocationManager.GPS_PROVIDER),
new LocationListener(LocationManager.NETWORK_PROVIDER)
};
private void initializeLocationManager() {
Log.e(TAG, "initializeLocationManager");
if (mLocationManager == null) {
mLocationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
}
}
@Override
public void onLocationChanged(Location location) {
Log.e(TAG, "onLocationChanged: " + location);
mLastLocation.set(location);
Toast.makeText(mContext, "Driver location :"+location.getLatitude()+" , "+location.getLongitude(), Toast.LENGTH_SHORT).show();
//TODO call web service to update driver location to server
driverLocationUpdateServerRequest(location);
}
@Override
public void onProviderDisabled(String provider){
Log.e(TAG, "onProviderDisabled: " + provider);
}
@Override
public void onProviderEnabled(String provider){
Log.e(TAG, "onProviderEnabled: " + provider);
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras){
Log.e(TAG, "onStatusChanged: " + provider);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
initializeLocationManager();
try {
mLocationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, LOCATION_INTERVAL, LOCATION_DISTANCE,
mLocationListeners[1]);
} catch (java.lang.SecurityException ex) {
Log.i(TAG, "fail to request location update, ignore", ex);
} catch (IllegalArgumentException ex) {
Log.d(TAG, "network provider does not exist, " + ex.getMessage());
}
try {
mLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, LOCATION_INTERVAL, LOCATION_DISTANCE,
mLocationListeners[0]);
} catch (java.lang.SecurityException ex) {
Log.i(TAG, "fail to request location update, ignore", ex);
} catch (IllegalArgumentException ex) {
Log.d(TAG, "gps provider does not exist " + ex.getMessage());
}
}
}
来源：https://stackoverflow.com/questions/28502513/how-get-the-current-latitud-and-longitud-without-use-getlastknownlocation-method