我已经使用 FusedLocation Provider API来获取用户的当前位置。当用户打开位置时，一切正常。
但是如果他关闭了位置，我想向用户提供一条消息。关闭位置时，requestLocationUpdates不调用onLocationChanged方法。可能这是意料之中的，但我想知道关闭位置时会调用什么，以便我可以捕获它以通知用户。下面是我正在使用的代码（选自 Stackoverflow 中的一个示例，我丢失了该链接）。
public class FusedLocationService implements
LocationListener,
GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener {
private static final String TAG = "FusedLocationService";
private static final long INTERVAL = 1000 * 30;
private static final long FASTEST_INTERVAL = 1000 * 5;
private static final long ONE_MIN = 1000 * 60;
private static final long REFRESH_TIME = ONE_MIN * 5;
private static final float MINIMUM_ACCURACY = 50.0f;
Activity locationActivity;
private LocationRequest locationRequest;
private GoogleApiClient googleApiClient;
private Location location;
private FusedLocationProviderApi fusedLocationProviderApi = LocationServices.FusedLocationApi;
FusedLocationReceiver locationReceiver = null;
public FusedLocationService(Activity locationActivity, FusedLocationReceiver locationReceiver) {
this.locationReceiver = locationReceiver;
locationRequest = LocationRequest.create();
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
locationRequest.setInterval(INTERVAL);
locationRequest.setFastestInterval(FASTEST_INTERVAL);
this.locationActivity = locationActivity;
googleApiClient = new GoogleApiClient.Builder(locationActivity)
.addApi(LocationServices.API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
if (googleApiClient != null) {
googleApiClient.connect();
}
}
@Override
public void onConnected(Bundle connectionHint) {
Log.i(TAG, "I'm connected now");
Location currentLocation = fusedLocationProviderApi.getLastLocation(googleApiClient);
if (currentLocation != null && currentLocation.getTime() > REFRESH_TIME) {
location = currentLocation;
} else {
fusedLocationProviderApi.requestLocationUpdates(googleApiClient, locationRequest, this);
// Schedule a Thread to unregister location listeners
Executors.newScheduledThreadPool(1).schedule(new Runnable() {
@Override
public void run() {
fusedLocationProviderApi.removeLocationUpdates(googleApiClient,
FusedLocationService.this);
}
}, ONE_MIN, TimeUnit.MILLISECONDS);
}
}
@Override
public void onLocationChanged(Location location) {
Log.i(TAG, "Location is changed!");
//if the existing location is empty or
//the current location accuracy is greater than existing accuracy
//then store the current location
if (null == this.location || location.getAccuracy() < this.location.getAccuracy()) {
this.location = location;
// let's inform my client class through the receiver
locationReceiver.onLocationChanged();
//if the accuracy is not better, remove all location updates for this listener
if (this.location.getAccuracy() < MINIMUM_ACCURACY) {
fusedLocationProviderApi.removeLocationUpdates(googleApiClient, this);
}
}
}
public Location getLocation() {
return this.location;
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
}
}