Android中的当前位置

Question

我已完成以下操作以获取当前位置。但有时getAddressLine（）方法给我null值。这种情况非常罕见。但我想永久地解决它。任何人都可以给我一个解决方案！

LocationManager locationManager;
    String provider;
    Location location;

    double lat;
    double lng;

    String address;
    String city;

    // How many Geocoder should return our GPSTracker
    int geocoderMaxResults = 1;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        view = inflater.inflate(R.layout.fragment_home, container, false);

        getActivity().getWindow().getDecorView().setSystemUiVisibility(
                View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                        | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                        | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                        | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);


        toolbar = (Toolbar) getActivity().findViewById(R.id.toolbar);
        statusBar = (FrameLayout) getActivity().findViewById(R.id.statusBar);
        ((MainActivity) getActivity()).getSupportActionBar().setDisplayShowTitleEnabled(true);

 locationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);
        // Define the criteria how to select the locatioin provider -> use
        // default
        Criteria criteria = new Criteria();
        provider = locationManager.getBestProvider(criteria, false);
        location = locationManager.getLastKnownLocation(provider);

        // Initialize the location fields
        if (location != null) {
            System.out.println("Provider " + provider + " has been selected.");
            onLocationChanged(location);

            address = getAddressLine(getActivity());
            city = getLocality(getActivity());


            ((MainActivity) getActivity()).getSupportActionBar().setTitle(address + ", " + city);

        } else {
            Toast.makeText(getActivity(), "Impossible to connect to Geocoder !!",
                    Toast.LENGTH_LONG).show();
        }
}


    @Override
    public void onLocationChanged(Location location) {

        lat = (double) location.getLatitude();
        lng = (double) location.getLongitude();
    }

    @Override
    public void onStatusChanged(String s, int i, Bundle bundle) {
        //To change body of implemented methods use File | Settings | File Templates.
    }

    @Override
    public void onProviderEnabled(String s) {
        //To change body of implemented methods use File | Settings | File Templates.
    }

    @Override
    public void onProviderDisabled(String s) {
        //To change body of implemented methods use File | Settings | File Templates.
    }

    /**
     * Get list of address by latitude and longitude
     * @return null or List<Address>
     */
    public List<Address> getGeocoderAddress(Context context) {
        if (location != null) {

            Geocoder geocoder = new Geocoder(context, Locale.ENGLISH);

            try {
                /**
                 * Geocoder.getFromLocation - Returns an array of Addresses
                 * that are known to describe the area immediately surrounding the given latitude and longitude.
                 */
                List<Address> addresses = geocoder.getFromLocation(lat, lng, this.geocoderMaxResults);

                return addresses;
            } catch (IOException e) {
                e.printStackTrace();
             //   Log.e(TAG, "Impossible to connect to Geocoder", e);
            }
        }

        return null;
    }

    /**
     * Try to get AddressLine
     * @return null or addressLine
     */
    public String getAddressLine(Context context) {
        List<Address> addresses = getGeocoderAddress(context);

        if (addresses != null && addresses.size() > 0) {
            Address address = addresses.get(0);
            String addressLine = address.getAddressLine(geocoderMaxResults);

            return addressLine;
        } else {
            return null;
        }
    }

    public String getLocality(Context context) {
        List<Address> addresses = getGeocoderAddress(context);

        if (addresses != null && addresses.size() > 0) {
            Address address = addresses.get(0);
            String locality = address.getLocality();

            return locality;
        }
        else {
            return null;
        }
    }

Answer 1

每个地点可能没有地址。如果您确定您的位置有地址且您的地理编码器无法提供，请重新启动手机并重试（我发现此解决方案没有真正的解决方案，尽管如您所说，这种情况非常罕见）。您必须提供“else”块才能在这些特殊情况下执行某些操作。

Answer 2

使用下面的代码获取用户的当前位置。这是Google最新的API（日期：2016年1月28日）。

confirm('...');