如何在谷歌地图上显示当前位置？

Question

there. I am a brand new learner of android and geocoding. And I wonder how I can display the current address rather than showing the "Here you are" message. I know I was supposed to use the getFromLocation() method to accomplish my goal, However. I do not know how I can do that and where to put it.

import android.Manifest;
import android.annotation.SuppressLint;
import android.content.pm.PackageManager;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.os.Bundle;
import android.widget.Toast;

import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.FragmentActivity;

import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.location.LocationCallback;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationResult;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.tasks.OnSuccessListener;

import java.io.IOException;
import java.util.List;
import java.util.Locale;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private final int REQUEST_LOCATION_PERMISSIONS = 0;
    private float mZoomLevel = 15;
    private GoogleMap mMap;
    private FusedLocationProviderClient mClient;
    private LocationRequest mLocationRequest;
    private LocationCallback mLocationCallback;

    @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);

        // Create location request
        mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(5000);
        mLocationRequest.setFastestInterval(3000);
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        mClient = LocationServices.getFusedLocationProviderClient(this);


        // Create location callback
        mLocationCallback = new LocationCallback() {
            @Override
            public void onLocationResult(LocationResult locationResult) {
                if (locationResult != null) {
                    for (Location location : locationResult.getLocations()) {
                        updateMap(location);
                    }
                }
            }
        };

        mClient = LocationServices.getFusedLocationProviderClient(this);
    }

    private void updateMap(Location location) {
        // Get current location


        LatLng myLatLng = new LatLng(location.getLatitude(),
                location.getLongitude());

        // Place a marker at the current location
        MarkerOptions myMarker = new MarkerOptions()
                .title("Here you are!")
                .position(myLatLng);


        // Remove previous marker
        mMap.clear();

        // Add new marker
        mMap.addMarker(myMarker);


        // Move and zoom to current location at the street level
        CameraUpdate update = CameraUpdateFactory.
                newLatLngZoom(myLatLng, mZoomLevel);
        mMap.animateCamera(update);
    }





    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        mMap.setOnCameraMoveListener(new GoogleMap.OnCameraMoveListener() {
            @Override
            public void onCameraMove() {
                CameraPosition cameraPosition = mMap.getCameraPosition();
                mZoomLevel = cameraPosition.zoom;
            }
        });

        mMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
            @Override
            public boolean onMarkerClick(Marker marker) {
                Toast.makeText(MapsActivity.this,"Lat: " + marker.getPosition().latitude +
                        "\nLong: " + marker.getPosition().longitude, Toast.LENGTH_LONG).show();
                return false;
            }
        });
    }


    @Override
    public void onPause() {
        super.onPause();
        mClient.removeLocationUpdates(mLocationCallback);
    }

    @SuppressLint("MissingPermission")
    @Override
    public void onResume() {
        super.onResume();

        if (hasLocationPermission()) {
            mClient.requestLocationUpdates(mLocationRequest, mLocationCallback, null);
        }
    }

    private boolean hasLocationPermission() {

        // Request fine location permission if not already granted
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

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

            return false;
        }

        return true;
    }
}

I was trying to add the following to the code to change the message to a specific location:

    Geocoder geocoder;
    List<Address> addresses;
    geocoder = new Geocoder(this, Locale.getDefault());
    try {
        addresses = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 1);
        updateMap(location);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Answer 1

getFromAddress method return list of possible address.you can get full address like bellow code.

List<Address> fromLocation = geocoder.getFromLocation(location.latitude, location.longitude, 1);
Address address = fromLocation.get(0);


String  zipCode = address.getPostalCode());
String city = address.getLocality();
String subAdmin =  address.getSubAdminArea();
String countryCode  = address.getCountryCode());
String state = address.getAdminArea());

Also you can update your marker as bellow

  MarkerOptions markerOptions = new MarkerOptions();
        markerOptions.draggable(true);
        markerOptions.position(latLng);
        markerOptions.title(city);// your text put here
        map.addMarker(markerOptions);