onMapLongClick () неправильно добавляет маркер. Он добавляет его, а затем удаляет.
Я следую руководству по включению карт Google в Android Studio. В целях отладки я поместил Toast в метод onMapLongClick для отображения «Местоположение сохранено», которое работает, но не сохраняет маркер. Также я использую эмулятор Nexus 4 API 23.
Вот код из MapsActivity.java:
public class MapsActivity extends FragmentActivity implements
OnMapReadyCallback, OnMapLongClickListener {
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 (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);
Location lastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
centerMapOnLocation(lastKnownLocation, "Your location");
}
}
}
public void centerMapOnLocation(Location location, String title){
LatLng userLocation = new LatLng(location.getLatitude(), location.getLongitude());
mMap.clear();
if(title != "Your location") {
mMap.addMarker(new MarkerOptions().position(userLocation).title(title));
}
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(userLocation, 10));
}
@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);
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mMap.setOnMapLongClickListener(this);
Intent intent = getIntent();
if(intent.getIntExtra("placeNumber", 0) == 0){
//zoom in on user's location
locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
locationListener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
centerMapOnLocation(location, "Your location");
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
@Override
public void onProviderEnabled(String s) {
}
@Override
public void onProviderDisabled(String s) {
}};
//If device is running SDK < 23
if(Build.VERSION.SDK_INT < 23){
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
}
else {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
Location lastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
centerMapOnLocation(lastKnownLocation, "Your location");
}else{
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
}
}
}
}
@Override
public void onMapLongClick(LatLng latLng) {
mMap.addMarker(new MarkerOptions().position(latLng).title("Your new memorable place"));
Toast.makeText(this, "Location saved", Toast.LENGTH_LONG).show();
}
}
Общая цель состоит в том, чтобы при длительном щелчке он добавлял маркер и сохранял это местоположение в ArrayList, который отображается в MainActivity.