LocationManager不在GoogleMap中显示位置

Question

我正在尝试构建我的第一个跟踪用户位置的Android应用。我试图通过我的Maps Activity Class中的以下java代码实现此目的：

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

private GoogleMap mMap;
LocationManager locationManager;

@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);
    locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        return;
    }
    if(locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)) {
        locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                double latitude = location.getLatitude();
                double longitude = location.getLongitude();

                LatLng latLng = new LatLng(latitude, longitude);
                Geocoder geocoder = new Geocoder(getApplicationContext());
                try {
                    List<Address> addressList = geocoder.getFromLocation(latitude, longitude, 1);
                    String str = addressList.get(0).getLocality();
                    mMap.addMarker(new MarkerOptions().position(latLng).title(str));
                    mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, 10.2f));
                }catch (IOException e){
                    e.printStackTrace();
                }

            }

            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {

            }

            @Override
            public void onProviderEnabled(String provider) {

            }

            @Override
            public void onProviderDisabled(String provider) {

            }
        });
    }else if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)){
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                double latitude = location.getLatitude();
                double longitude = location.getLongitude();

                LatLng latLng = new LatLng(latitude, longitude);
                Geocoder geocoder = new Geocoder(getApplicationContext());
                try {
                    List<Address> addressList = geocoder.getFromLocation(latitude, longitude, 1);
                    String str = addressList.get(0).getLocality();
                    mMap.addMarker(new MarkerOptions().position(latLng).title(str));
                    mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, 10.2f));
                }catch (IOException e){
                    e.printStackTrace();
                }
            }

            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {

            }

            @Override
            public void onProviderEnabled(String provider) {

            }

            @Override
            public void onProviderDisabled(String provider) {

            }
        });
    }
}

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

    // Add a marker in Sydney and move the camera
    //LatLng sydney = new LatLng(-34, 151);
    //mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
    //mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}

以下许可

 <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

但是我的Android手机和模拟器只显示全局地图视图。 应用程序执行API调用并请求它所需的一切，但信息不会显示。

此外，当只在地图上放置标记为onMapReady(GoogleMap googleMap)时，它确实有效。

我正在三星Galaxy S5和模拟Nexus 5X上测试我的应用程序。

编译版本：7.1.1 构建工具版本26.0.2