Weather App，如何从MapActivity获取经度和纬度

这是我第一次使用stackoverflow，对不起我的问题 . 我一直在学习java和swift只有4-5个月，所以我只是一个初学者 . 我正在编写一个简单的应用程序与谷歌 Map 和一些其他功能，如天气活动 . Map 活动运行完美，还有Wheather活动，但仅限静态纬度和经度：

asyncTask.execute("28.125696","-15.440090" );

如何在asyncTask.execute（...）中的MainActivityWeather中实现get currentLocation.getLatitude（），currentLocation.getLongitude（）; ？我在想吗？这是一个很好的方法来构建一个当前位置数据的天文应用程序？ Map 活动：

public class MapActivity extends AppCompatActivity implements OnMapReadyCallback, GoogleApiClient.OnConnectionFailedListener { 

 @Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

}

@Override
public void onMapReady(GoogleMap googleMap) {
    Toast.makeText(this, "Map is Ready", Toast.LENGTH_SHORT).show();
    Log.d(TAG, "onMapReady: map is ready");
    mMap = googleMap;

    if (mLocationPermissionsGranted) {
        getDeviceLocation();

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        mMap.setMyLocationEnabled(true);
        mMap.getUiSettings().setMyLocationButtonEnabled(false);
        init();
    }
}

private static final String TAG = "MapActivity";

private static final String FINE_LOCATION = Manifest.permission.ACCESS_FINE_LOCATION;
private static final String COURSE_LOCATION = Manifest.permission.ACCESS_COARSE_LOCATION;
private static final int LOCATION_PERMISSION_REQUEST_CODE = 1234;
private static final float DEFAULT_ZOOM = 15f;
public static final LatLngBounds LAT_LNG_BOUNDS = new LatLngBounds(
      new LatLng(-40, -168), new LatLng(71, 136)
);
//widgets

private AutoCompleteTextView mSearchText;
private ImageView mGps;

//vars
private Boolean mLocationPermissionsGranted = false;
private GoogleMap mMap;
private FusedLocationProviderClient mFusedLocationProviderClient;
private PlaceAutoCompleteAdapter mPlaceAutoCompleteAdapter;
private GoogleApiClient mGoogleApiClient;
private PlaceInfo mPlace;

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_map);
    mSearchText = (AutoCompleteTextView) findViewById(R.id.input_search);
    mGps = (ImageView) findViewById(R.id.ic_gps);

    getLocationPermission();

    BottomNavigationView bottomNav = findViewById(R.id.bottom_nav);
    BottomNavigationViewHelper.removeShiftMode(bottomNav);
    bottomNav.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {
            switch (item.getItemId()){
                case R.id.nav_menu:

                    Intent intent0 = new Intent(MapActivity.this, MainActivity.class);
                    startActivity(intent0);
                    break;

                case R.id.nav_note:
                    Intent intent1 = new Intent(MapActivity.this, MainListActivity.class);
                    startActivity(intent1);
                    break;
                case R.id.nav_map:

                    break;

                case R.id.nav_attraction:
                    Intent intent3 = new Intent(MapActivity.this, MainActivityGrid.class);
                    startActivity(intent3);
                    break;

            }
            return false;
        }
    });

}

private void init(){
    Log.d(TAG, "init: initializing");

    mGoogleApiClient = new GoogleApiClient
            .Builder(this)
            .addApi(Places.GEO_DATA_API)
            .addApi(Places.PLACE_DETECTION_API)
            .enableAutoManage(this, this)
            .build();

    mSearchText.setOnItemClickListener(mAutocompleteClickListener );

    mPlaceAutoCompleteAdapter = new PlaceAutoCompleteAdapter(this, mGoogleApiClient, LAT_LNG_BOUNDS, null);

    mSearchText.setAdapter(mPlaceAutoCompleteAdapter);

    mSearchText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
        @Override
        public boolean onEditorAction(TextView textView, int actionId, KeyEvent keyEvent) {
            if(actionId == EditorInfo.IME_ACTION_SEARCH
                    || actionId == EditorInfo.IME_ACTION_DONE
                    || keyEvent.getAction() == KeyEvent.ACTION_DOWN
                    || keyEvent.getAction() == KeyEvent.KEYCODE_ENTER){

                //execute our method for searching
                geoLocate();
            }

            return false;
        }
    });
    mGps.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Log.d(TAG, "onClick: clicked gps icon");
            getDeviceLocation();

        }
    });

    hideSoftKeyboard();
}

private void geoLocate(){
    Log.d(TAG, "geoLocate: geolocating");

    String searchString = mSearchText.getText().toString();

    Geocoder geocoder = new Geocoder(MapActivity.this);
    List<Address> list = new ArrayList<>();
    try{
        list = geocoder.getFromLocationName(searchString,1);

    }catch (IOException e) {
        Log.d(TAG, "geoLocate: IOException " +e.getMessage());
    }
    if(list.size() > 0 ){
        Address address = list.get(0);
        Log.d(TAG, "geoLocate: found a location "+ address.toString());

       moveCamera(new LatLng(address.getLatitude(), address.getLongitude()), DEFAULT_ZOOM, address.getAddressLine(0));
    }
}

private void getDeviceLocation(){
    Log.d(TAG, "getDeviceLocation: getting the devices current location");

    mFusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this);

    try{
        if(mLocationPermissionsGranted){

            final Task location = mFusedLocationProviderClient.getLastLocation();
            location.addOnCompleteListener(new OnCompleteListener() {
                @Override
                public void onComplete(@NonNull Task task) {
                    if(task.isSuccessful()&& task.getResult() != null){
                        Log.d(TAG, "onComplete: found location!");
                        Location currentLocation = (Location) task.getResult();

                        moveCamera(new LatLng(currentLocation.getLatitude(), currentLocation.getLongitude()),
                                DEFAULT_ZOOM, "My location");

                    }else{
                        Log.d(TAG, "onComplete: current location is null");
                        Toast.makeText(MapActivity.this, "unable to get current location", Toast.LENGTH_SHORT).show();
                    }
                }
            });
        }
    }catch (SecurityException e){
        Log.e(TAG, "getDeviceLocation: SecurityException: " + e.getMessage() );
    }
}

private void moveCamera(LatLng latLng, float zoom, String title){
    Log.d(TAG, "moveCamera: moving the camera to: lat: " + latLng.latitude + ", lng: " + latLng.longitude );
    mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, zoom));

    if(!title.equals("My location")){
        MarkerOptions options = new MarkerOptions().position(latLng).title(title);
        mMap.addMarker(options);
    }
    hideSoftKeyboard();

}

private void initMap(){
    Log.d(TAG, "initMap: initializing map");
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);

    mapFragment.getMapAsync(MapActivity.this);
}

private void getLocationPermission(){
    Log.d(TAG, "getLocationPermission: getting location permissions");
    String[] permissions = {Manifest.permission.ACCESS_FINE_LOCATION,
            Manifest.permission.ACCESS_COARSE_LOCATION};

    if(ContextCompat.checkSelfPermission(this.getApplicationContext(),
            FINE_LOCATION) == PackageManager.PERMISSION_GRANTED){
        if(ContextCompat.checkSelfPermission(this.getApplicationContext(),
                COURSE_LOCATION) == PackageManager.PERMISSION_GRANTED){
            mLocationPermissionsGranted = true;
            initMap();
        }else{
            ActivityCompat.requestPermissions(this,
                    permissions,
                    LOCATION_PERMISSION_REQUEST_CODE);
        }
    }else{
        ActivityCompat.requestPermissions(this,
                permissions,
                LOCATION_PERMISSION_REQUEST_CODE);
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    Log.d(TAG, "onRequestPermissionsResult: called.");
    mLocationPermissionsGranted = false;

    switch(requestCode){
        case LOCATION_PERMISSION_REQUEST_CODE:{
            if(grantResults.length > 0){
                for(int i = 0; i < grantResults.length; i++){
                    if(grantResults[i] != PackageManager.PERMISSION_GRANTED){
                        mLocationPermissionsGranted = false;
                        Log.d(TAG, "onRequestPermissionsResult: permission failed");
                        return;
                    }
                }
                Log.d(TAG, "onRequestPermissionsResult: permission granted");
                mLocationPermissionsGranted = true;
                //initialize our map
                initMap();
            }
        }
    }
}
 

 private void hideSoftKeyboard(){
        this.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
} 

 private AdapterView.OnItemClickListener mAutocompleteClickListener = new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
        hideSoftKeyboard();

        final AutocompletePrediction item = mPlaceAutoCompleteAdapter.getItem(i);
        final String placeId = item.getPlaceId();

        PendingResult<PlaceBuffer> placeResult = Places.GeoDataApi
                .getPlaceById(mGoogleApiClient, placeId);
        placeResult.setResultCallback(mUpdatePlaceDetailsCallback);
    }
};
private ResultCallback<PlaceBuffer> mUpdatePlaceDetailsCallback = new ResultCallback<PlaceBuffer>() {
    @Override
    public void onResult(@NonNull PlaceBuffer places) {
        if (!places.getStatus().isSuccess()) {
            Log.d(TAG, "onResult: Place query did not mplete successfully" + places.getStatus().toString());
            places.release();
            return;
        }
        final Place place = places.get(0);
        try{
            mPlace = new PlaceInfo();
            mPlace.setName(place.getName().toString());
            Log.d(TAG, "onResult: name: " + place.getName());
            mPlace.setAddress(place.getAddress().toString());
            Log.d(TAG, "onResult: address: " + place.getAddress());
            mPlace.setAttributions(place.getAttributions().toString());
            Log.d(TAG, "onResult: attributions: " + place.getAttributions());
            mPlace.setId(place.getId());
            Log.d(TAG, "onResult: id:" + place.getId());
            mPlace.setLatlng(place.getLatLng());
            Log.d(TAG, "onResult: latlng: " + place.getLatLng());
            mPlace.setRating(place.getRating());
            Log.d(TAG, "onResult: rating: " + place.getRating());
            mPlace.setPhoneNumber(place.getPhoneNumber().toString());
            Log.d(TAG, "onResult: phone number: " + place.getPhoneNumber());
            mPlace.setWebsiteUri(place.getWebsiteUri());
            Log.d(TAG, "onResult: website uri: " + place.getWebsiteUri());

            Log.d(TAG, "onResult: place: " + mPlace.toString());
        }catch (NullPointerException e){
            Log.e(TAG, "onResult: NullPointerException: " + e.getMessage() );
        }

        moveCamera(new LatLng(place.getViewport().getCenter().latitude,
                place.getViewport().getCenter().longitude), DEFAULT_ZOOM, mPlace.getName());

        places.release();
    }

};}
 

 

 Wheather Activities: 

 public class MainActivityWeather extends AppCompatActivity { 

 private static final String TAG = "WeatherActivity";

TextView cityField, detailsField, currentTemperatureField, humidity_field, pressure_field, weatherIcon, updatedField;

Typeface weatherFont;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
 

 //        getSupportActionBar().hide();
        setContentView(R.layout.activity_main_weather); 

    weatherFont = Typeface.createFromAsset(getApplicationContext().getAssets(), "fonts/weathericons-regular-webfont.ttf");

    cityField = (TextView)findViewById(R.id.city_field);
    updatedField = (TextView)findViewById(R.id.updated_field);
    detailsField = (TextView)findViewById(R.id.details_field);
    currentTemperatureField = (TextView)findViewById(R.id.current_temperature_field);
    humidity_field = (TextView)findViewById(R.id.humidity_field);
    pressure_field = (TextView)findViewById(R.id.pressure_field);
    weatherIcon = (TextView)findViewById(R.id.weather_icon);
    weatherIcon.setTypeface(weatherFont);

    Function.placeIdTask asyncTask =new Function.placeIdTask(new Function.AsyncResponse() {
        public void processFinish(String weather_city, String weather_description, String weather_temperature, String weather_humidity, String weather_pressure, String weather_updatedOn, String weather_iconText, String sun_rise) {

            cityField.setText(weather_city);
            updatedField.setText(weather_updatedOn);
            detailsField.setText(weather_description);
            currentTemperatureField.setText(weather_temperature);
            humidity_field.setText("Humidity: "+weather_humidity);
            pressure_field.setText("Pressure: "+weather_pressure);
            weatherIcon.setText(Html.fromHtml(weather_iconText));

        }

    });

    asyncTask.execute( ); //  asyncTask.execute("Latitude", "Longitude")

}}
 

 
public class Function { 

private static final String OPEN_WEATHER_MAP_URL =
        "http://api.openweathermap.org/data/2.5/weather?lat=%s&lon=%s&units=metric";

private static final String OPEN_WEATHER_MAP_API = "fdbf72863aba44b6fc7ce9e3324a689f";

public static String setWeatherIcon(int actualId, long sunrise, long sunset){
    int id = actualId / 100;
    String icon = "";
    if(actualId == 800){
        long currentTime = new Date().getTime();
        if(currentTime>=sunrise && currentTime<sunset) {
            icon = "&#xf00d;";
        } else {
            icon = "&#xf02e;";
        }
    } else {
        switch(id) {
            case 2 : icon = "&#xf01e;";
                break;
            case 3 : icon = "&#xf01c;";
                break;
            case 7 : icon = "&#xf014;";
                break;
            case 8 : icon = "&#xf013;";
                break;
            case 6 : icon = "&#xf01b;";
                break;
            case 5 : icon = "&#xf019;";
                break;
        }
    }
    return icon;
}

public interface AsyncResponse {

    void processFinish(String output1, String output2, String output3, String output4, String output5, String output6, String output7, String output8);
}

public static class placeIdTask extends AsyncTask<String, Void, JSONObject> {

    public AsyncResponse delegate = null;//Call back interface

    public placeIdTask(AsyncResponse asyncResponse) {
        delegate = asyncResponse;//Assigning call back interfacethrough constructor
    }

    @Override
    protected JSONObject doInBackground(String... params) {

        JSONObject jsonWeather = null;
        try {
            jsonWeather = getWeatherJSON(params[0], params[1]);
        } catch (Exception e) {
            Log.d("Error", "Cannot process JSON results", e);
        }

        return jsonWeather;
    }

    @Override
    protected void onPostExecute(JSONObject json) {
        try {
            if(json != null){
                JSONObject details = json.getJSONArray("weather").getJSONObject(0);
                JSONObject main = json.getJSONObject("main");
                DateFormat df = DateFormat.getDateTimeInstance();

                String city = json.getString("name").toUpperCase(Locale.US) + ", " + json.getJSONObject("sys").getString("country");
                String description = details.getString("description").toUpperCase(Locale.US);
                String temperature = String.format("%.2f", main.getDouble("temp"))+ "°";
                String humidity = main.getString("humidity") + "%";
                String pressure = main.getString("pressure") + " hPa";
                String updatedOn = df.format(new Date(json.getLong("dt")*1000));
                String iconText = setWeatherIcon(details.getInt("id"),
                        json.getJSONObject("sys").getLong("sunrise") * 1000,
                        json.getJSONObject("sys").getLong("sunset") * 1000);

                delegate.processFinish(city, description, temperature, humidity, pressure, updatedOn, iconText, ""+ (json.getJSONObject("sys").getLong("sunrise") * 1000));

            }
        } catch (JSONException e) {
            //Log.e(LOG_TAG, "Cannot process JSON results", e);
        }

    }
}

public static JSONObject getWeatherJSON(String lat, String lon){
    try {
        URL url = new URL(String.format(OPEN_WEATHER_MAP_URL, lat, lon));
        HttpURLConnection connection =
                (HttpURLConnection)url.openConnection();

        connection.addRequestProperty("x-api-key", OPEN_WEATHER_MAP_API);

        BufferedReader reader = new BufferedReader(
                new InputStreamReader(connection.getInputStream()));

        StringBuffer json = new StringBuffer(1024);
        String tmp="";
        while((tmp=reader.readLine())!=null)
            json.append(tmp).append("\n");
        reader.close();

        JSONObject data = new JSONObject(json.toString());

        // This value will be 404 if the request was not
        // successful
        if(data.getInt("cod") != 200){
            return null;
        }

        return data;
    }catch(Exception e){
        return null;
    }
}}