Switching between network and GPS provider
I want to implement a locationListener which will switch between network and GPS providers based on availability.
For example if GPS is not enab开发者_如何学JAVAled I want it to use network but as soon as GPS is on then I want it to stop listening for location updates from network and start listening from GPS.
Similarly I want it to start listening for updates from network as soon as GPS is switched off.
Is that possible?
Subquestion
Is GPS as fast as network in providing a location fix?
Sure, you just get the providers for the network and GPS and pass whichever you want to locationManager.requestLocationUpdates()
.
When you want to stop listening to a certain provider, call locationManager.removeUpdates()
with the listener object you specified in locationManager.requestLocationUpdates()
.
Network:
Criteria crit = new Criteria();
crit.setPowerRequirement(Criteria.POWER_LOW);
crit.setAccuracy(Criteria.ACCURACY_COARSE);
String provider = locationManager.getBestProvider(crit, false);
GPS:
Criteria crit2 = new Criteria();
crit2.setAccuracy(Criteria.ACCURACY_FINE);
provider2 = locationManager.getBestProvider(crit2, false);
You can use LocationManager.isProviderEnabled() doc to see if the appropriate provider is enabled/disabled. There's more info available in the LocationManager docs.
GPS is usually much slower than network since you have to find 3+ far-away satellites, etc.
I am using this
LocationManager locationManager;
LocationListener locationListener;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
locationManager = (LocationManager) this
.getSystemService(Context.LOCATION_SERVICE);
String locationProvider = LocationManager.NETWORK_PROVIDER;
Location lastKnownLocation = locationManager
.getLastKnownLocation(locationProvider);
if (lastKnownLocation == null) {
locationProvider = LocationManager.GPS_PROVIDER;
lastKnownLocation = locationManager
.getLastKnownLocation(locationProvider);
}
if (lastKnownLocation != null) {
makeUseOfNewLocation(lastKnownLocation);
}
locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
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
if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 0, 0, locationListener);
} else {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
}
}
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