Моё базовое c приложение определения местоположения до сих пор работает на моем Galaxy A20, работающем с API 29, но отлично работает на всех моих эмуляторах, использующих один и тот же API. Я не уверен, что проблема может быть, так как я не испытывал с LOGCAT, но ошибка выглядит следующим образом:
Попытка вызвать виртуальный метод 'double android .location.Location.getLatitude ()' для нулевого объекта ссылка.
ОШИБКА НА ЛИНИИ 117 в моем проекте (в конце). Но я выделил это здесь
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
LocationManager locationManager;
LocationListener locationListener;
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == 1){
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
if (ContextCompat.checkSelfPermission(this , Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED)
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER ,0 ,0 , locationListener);
}
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
locationListener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
LatLng userLocation = new LatLng(location.getLatitude(), location.getLongitude());
mMap.clear();
mMap.addMarker(new MarkerOptions().position(userLocation).title("Marker in user house"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(userLocation));
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
@Override
public void onProviderEnabled(String s) {
}
@Override
public void onProviderDisabled(String s) {
}
};
if (ContextCompat.checkSelfPermission(this , Manifest.permission.ACCESS_FINE_LOCATION ) != PackageManager.PERMISSION_GRANTED){
ActivityCompat.requestPermissions(this , new String[]{Manifest.permission.ACCESS_FINE_LOCATION} , 1);
}
else{
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER , 0 , 0 , locationListener);
Location lastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
LatLng userLocation = new LatLng(lastKnownLocation.getLatitude(), lastKnownLocation.getLongitude()); // ◅ THE ERROR OCCOURS HERE********
mMap.clear();
mMap.addMarker(new MarkerOptions().position(userLocation).title("Marker in user house"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(userLocation));
}
}
}