[Android][Google Maps]: Get the Address of locatio

问题:

I have been googling this for hours but no luck so far.

I want to get the address of the location where the map is touched / tapped.

I understand that in order to get the address i need to reverse geocode the coordinates. But how do i get the coordinates from the map in the first place?

回答1:

All you need to do is set up a OnMapClickListener, and then the onMapClick() override will give you a LatLng object. Then, use a Geocoder object to get the address of the point that was just clicked on.

In this simple example, I've also added a Marker every time the user clicks a new point on the map.

Here is the main piece of functionality that you need:

mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {

        @Override
        public void onMapClick(LatLng point) {
            //save current location
            latLng = point;

            List<Address> addresses = new ArrayList<>();
            try {
                addresses = geocoder.getFromLocation(point.latitude, point.longitude,1);
            } catch (IOException e) {
                e.printStackTrace();
            }

            android.location.Address address = addresses.get(0);

            if (address != null) {
                StringBuilder sb = new StringBuilder();
                for (int i = 0; i < address.getMaxAddressLineIndex(); i++){
                    sb.append(address.getAddressLine(i) + "\n");
                }
                Toast.makeText(MapsActivity.this, sb.toString(), Toast.LENGTH_LONG).show();
            }

            //remove previously placed Marker
            if (marker != null) {
                marker.remove();
            }

            //place marker where user just clicked
            marker = mMap.addMarker(new MarkerOptions().position(point).title("Marker")
                    .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA)));

        }
    });

Here is the full class that I used to test this:

public class MapsActivity extends AppCompatActivity {

    private GoogleMap mMap;
    private LatLng latLng;
    private Marker marker;
    Geocoder geocoder;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);

        geocoder = new Geocoder(this, Locale.getDefault());

        setUpMapIfNeeded();
    }

    @Override
    protected void onResume() {
        super.onResume();
        setUpMapIfNeeded();
    }

    private void setUpMapIfNeeded() {
        // Do a null check to confirm that we have not already instantiated the map.
        if (mMap == null) {
            // Try to obtain the map from the SupportMapFragment.
            mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
                    .getMap();
            // Check if we were successful in obtaining the map.
            if (mMap != null) {
                setUpMap();
            }
        }
    }

    private void setUpMap() {

        mMap.setMyLocationEnabled(true);
        mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
        mMap.getUiSettings().setMapToolbarEnabled(false);

        mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {

            @Override
            public void onMapClick(LatLng point) {
                //save current location
                latLng = point;

                List<Address> addresses = new ArrayList<>();
                try {
                    addresses = geocoder.getFromLocation(point.latitude, point.longitude,1);
                } catch (IOException e) {
                    e.printStackTrace();
                }

                android.location.Address address = addresses.get(0);

                if (address != null) {
                    StringBuilder sb = new StringBuilder();
                    for (int i = 0; i < address.getMaxAddressLineIndex(); i++){
                        sb.append(address.getAddressLine(i) + "\n");
                    }
                    Toast.makeText(MapsActivity.this, sb.toString(), Toast.LENGTH_LONG).show();
                }

                //remove previously placed Marker
                if (marker != null) {
                    marker.remove();
                }

                //place marker where user just clicked
                marker = mMap.addMarker(new MarkerOptions().position(point).title("Marker")
                        .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA)));

            }
        });

    }
}

Result of tapping the map in two different points:

回答2:

Google Map has callbacks to do that like this one or this one.

Just implement them in your code and as soon as they're fired, just make a reverse geocode the coordinates. You actually found the most complicated part (you understood that you need to reverse geocode).