问题
I have the following code:
public class MyLocationListener implements LocationListener {
@Override
public void onLocationChanged(Location loc) {
// called when the listener is notified with a location update from the GPS
Log.d("Latitude", Double.toString(loc.getLatitude()));
Log.d("Longitude", Double.toString(loc.getLongitude()));
}
@Override
public void onProviderDisabled(String provider) {
// called when the GPS provider is turned off (user turning off the GPS on the phone)
}
@Override
public void onProviderEnabled(String provider) {
// called when the GPS provider is turned on (user turning on the GPS on the phone)
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
and in my MainActivity
LocationListener locationListener = new MyLocationListener();
LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
Now, all I want is to receive the current position of the device ONCE to the MainActivity class (get altitude and longitude variables to use later in the application).
A. how do I stop receiving the location after a single time? The function lm.removeUpdates(listener) can only be called in the MainActivity class.
B. basically the same. How do I connect between the MyLocationListener class and the MainActivity one?
Sorry, I'm a newbie to Android and Java development. And thanks!
回答1:
You may use the following sample code:
public class LocationGetter {
private final Context context;
private Location location = null;
private final Cordinate gotLocationLock = new Cordinate();
private final LocationResult locationResult = new LocationResult() {
@Override
public void gotLocation(Location location) {
synchronized (gotLocationLock) {
LocationGetter.this.location = location;
gotLocationLock.notifyAll();
Looper.myLooper().quit();
}
}
};
public LocationGetter(Context context) {
if (context == null)
throw new IllegalArgumentException("context == null");
this.context = context;
}
public void getLocation(int maxWaitingTime, int updateTimeout) {
try {
final int updateTimeoutPar = updateTimeout;
synchronized (gotLocationLock) {
new Thread() {
public void run() {
Looper.prepare();
LocationResolver locationResolver = new LocationResolver();
locationResolver.prepare();
locationResolver.getLocation(context, locationResult, updateTimeoutPar);
Looper.loop();
}
}.start();
gotLocationLock.wait(maxWaitingTime);
}
} catch (InterruptedException e1) {
e1.printStackTrace();
}
gteAddress ();
}
public double getLatitude() {
return location.getLatitude();
}
public double getLongitude() {
return location.getLongitude();
}
In your activity use:
_locationGetter=new LocationGetter(context);
_locationGetter.getLocation(200000000, 10000000);
_locationGetter.getLongitude();
_locationGetter.getLatitude();
回答2:
You can also use LocationManager.removeUpdates after obtining the coordinates (and possibly checking if the coordinates are sufficient for your needs):
@Override
public void onLocationChanged(Location loc) {
// called when the listener is notified with a location update from the GPS
Log.d("Latitude", Double.toString(loc.getLatitude()));
Log.d("Longitude", Double.toString(loc.getLongitude()));
lm.removeUpdates(this);
}
来源:https://stackoverflow.com/questions/12446742/android-onlocationchanged-and-mainactivity-class