如何从android google map v2中的给定地址获取经度和经度？

Question

我正在使用谷歌地图v2 android和地图也显示在我的应用程序中.我只想从给定的地址获取纬度和经度.

示例:在文本字段中,如果我键入"Indore",那么我将获得该城市的纬度和经度.

Answer 1

您可以使用此方法

 public void getLatLongFromPlace(String place) {
            try {
                Geocoder selected_place_geocoder = new Geocoder(context);
                List<Address> address;

                address = selected_place_geocoder.getFromLocationName(place, 5);

                if (address == null) {
                    d.dismiss();
                } else {
                    Address location = address.get(0);
                               Latitude lat= location.getLatitude();
                Longitude lng = location.getLongitude();

                }

            } catch (Exception e) {
                e.printStackTrace();
fetchLatLongFromService fetch_latlng_from_service_abc = new fetchLatLongFromService(
                        place.replaceAll("\\s+", ""));
                fetch_latlng_from_service_abc.execute();

            }

        }


//Sometimes happens that device gives location = null

    public class fetchLatLongFromService extends
                AsyncTask<Void, Void, StringBuilder> {
            String place;


            public fetchLatLongFromService(String place) {
                super();
                this.place = place;

            }

            @Override
            protected void onCancelled() {
                // TODO Auto-generated method stub
                super.onCancelled();
                this.cancel(true);
            }

            @Override
            protected StringBuilder doInBackground(Void... params) {
                // TODO Auto-generated method stub
                try {
                    HttpURLConnection conn = null;
                    StringBuilder jsonResults = new StringBuilder();
                    String googleMapUrl = "http://maps.googleapis.com/maps/api/geocode/json?address="
                            + this.place + "&sensor=false";

                    URL url = new URL(googleMapUrl);
                    conn = (HttpURLConnection) url.openConnection();
                    InputStreamReader in = new InputStreamReader(
                            conn.getInputStream());
                    int read;
                    char[] buff = new char[1024];
                    while ((read = in.read(buff)) != -1) {
                        jsonResults.append(buff, 0, read);
                    }
                    String a = "";
                    return jsonResults;
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return null;

            }

        @Override
        protected void onPostExecute(StringBuilder result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            try {
                JSONObject jsonObj = new JSONObject(result.toString());
                JSONArray resultJsonArray = jsonObj.getJSONArray("results");

                // Extract the Place descriptions from the results
                // resultList = new ArrayList<String>(resultJsonArray.length());

                JSONObject before_geometry_jsonObj = resultJsonArray
                        .getJSONObject(0);

                JSONObject geometry_jsonObj = before_geometry_jsonObj
                        .getJSONObject("geometry");

                JSONObject location_jsonObj = geometry_jsonObj
                        .getJSONObject("location");

                String lat_helper = location_jsonObj.getString("lat");
                double lat = Double.valueOf(lat_helper);


                String lng_helper = location_jsonObj.getString("lng");
                double lng = Double.valueOf(lng_helper);


                LatLng point = new LatLng(lat, lng);


            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();

            }
        }
    }

找到位置的常用方法是我之前提到的那个,但有时网络提供商或GPS提供商无法获取位置因此给出空值,它也发生在我身上但是当位置为空并抛出异常时,使用谷歌网络服务来获取lat和long.首先尝试从上面的方法获取,如果它失败,有时会使用第二种方法从Web服务获取它.