How to add marker on google maps android?

Question

I am a beginner in Android programming. I already looked at similar questions and answers but I still can\'t figure out why this doesn\'t work. When I try this on the emulat

Answer 1

This code in MapsActivity works for me :

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, GoogleMap.OnMapLongClickListener {

private GoogleMap mMap;
LocationManager locationManager;
LocationListener locationListener;

public void centreMapOnLocation(Location location, String title){

    LatLng userLocation = new LatLng(location.getLatitude(),location.getLongitude());
    mMap.clear();
    mMap.addMarker(new MarkerOptions().position(userLocation).title(title));
    mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(userLocation,12));

}

@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);
            centreMapOnLocation(lastKnownLocation,"Your Location");
        }
    }
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps2);
    // 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("Place Number",0) == 0 ){

        // Zoom into users location
        locationManager = (LocationManager)this.getSystemService(Context.LOCATION_SERVICE);
        locationListener = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                centreMapOnLocation(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 (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);
                centreMapOnLocation(lastKnownLocation,"Your Location");
        } else {

            ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.ACCESS_FINE_LOCATION},1);
        }
    } else {

        Location placeLocation = new Location(LocationManager.GPS_PROVIDER);
        placeLocation.setLatitude(MainActivity.location.get(intent.getIntExtra("Place Number",0)).latitude);
        placeLocation.setLongitude(MainActivity.location.get(intent.getIntExtra("Place Number",0)).longitude);

        centreMapOnLocation(placeLocation,MainActivity.places.get(intent.getIntExtra("Place Number",0)));
    }


}


@Override
public void onMapLongClick(LatLng latLng) {
    Geocoder geocoder = new Geocoder(getApplicationContext(), Locale.getDefault());
    String adress ="";
    try {
        List
 listaddress = geocoder.getFromLocation(latLng.latitude,latLng.longitude,1);

        if (listaddress != null && listaddress.size()>0){
            if (listaddress.get(0).getThoroughfare() != null){

                if (listaddress.get(0).getSubThoroughfare() != null){
                    adress += listaddress.get(0).getSubThoroughfare() + "";

                }
                adress += listaddress.get(0).getThoroughfare();
            }

        }

    }catch (Exception e){
        e.printStackTrace();
    }

    mMap.addMarker(new MarkerOptions().position(latLng).title(adress));

    MainActivity.places.add(adress);
    MainActivity.location.add(latLng);
    MainActivity.arrayAdapter.notifyDataSetChanged();

    Toast.makeText(this, "Location Saved..!", Toast.LENGTH_SHORT).show();

}

}