Android - Google Maps - LocationListener - adding the onLocationChanged marker causes the app to crash
I want the marker to show my current location. All required permissions are added. When I comment out mMap.addMarker and mMap.moveCamera the app is running and Googlemaps is displayed. If I allow one of these two in my code, the app crashes before the card even opens.
I tried to remove the marker if it is not null, but that doesn't solve the problem.
Do you guys know how I can get the application to work?
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, LocationListener {
private GoogleMap mMap;
private List<LatLng> fountain = null;
private LocationManager locationManager;
private double posLat;
private double posLng;
private LatLng position;
private Marker mPosition;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
startGPS();
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// Add a marker in Sydney and move the camera
LatLng sydney = new LatLng(48.16786112327462, 16.383984438313828);
mPosition = mMap.addMarker(new MarkerOptions().position(sydney).title("Your Position").icon(BitmapDescriptorFactory.fromResource(R.drawable.location)));
mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}
//--------------------------------------------GPS Listener---------------------------------------
public void startGPS() {
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED
&& ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, 5);
}
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 3000, 5, this);
onLocationChanged(locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER));
}
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case 5: {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
} else {
getDialog2("Keine Erlaubnis für GPS").show();
}
}
}
}
@Override
public void onLocationChanged(Location location) {
posLat = location.getLatitude();
posLng = location.getLongitude();
position = new LatLng(posLat, posLng);
if (mPosition != null) {
mPosition.remove();
}
mPosition = mMap.addMarker(new MarkerOptions().position(position).title("Your position").
icon(BitmapDescriptorFactory.fromResource(R.drawable.location)));
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(position, 11));
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
// ---------------------------- Helper methods --------------- --- -----------------------------
public Dialog getDialog2(String string) {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(string);
builder.setPositiveButton("OK",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
finish();
}
});
return builder.create();
}
public Dialog getDialog(String string) {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(string);
builder.setPositiveButton("OK",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
return builder.create();
}
}
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Ok, I have already solved the problem. So I am posting the solution here.
I have implemented the LocationListener interface in MapsActivity and for some reason it doesn't work that way. I can get the geo coordinates, but as soon as I want to move the camera or add a marker, the app crashes when it opens.
I don't know why, but instead of:
locationManager.requestLocationUpdates (LocationManager.GPS_PROVIDER, 3000, 5, this)
I override the implementation of LocationListener and just create a new one at the position, this ::
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 3000, 5, new LocationListener() {
@Override
public void onLocationChanged(Location location) {
posLat = location.getLatitude();
posLng = location.getLongitude();
position = new LatLng(posLat, posLng);
if (mPosition != null) {
mPosition.remove();
}
mPosition = mMap.addMarker(new MarkerOptions().position(position).title("Your position").
icon(BitmapDescriptorFactory.fromResource(R.drawable.location)));
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(position, 11));
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
}
);
and in this way it works without problem.
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