Question

我有一个片段，可以加载谷歌地图上的所有商店位置。但现在我只想加载距离当前位置5英里范围内的商店。

这是我的代码：

public class NearMeFragment extends Fragment implements GooglePlayServicesClient.ConnectionCallbacks,
    GooglePlayServicesClient.OnConnectionFailedListener, LocationListener {

        GoogleMap map;
        LatLng latlng;
        private LocationRequest lr;
        private LocationClient lc;
        MapFragment mapFragment;
        //ImageView iv;
        private static View view;
        Response response;

    public NearMeFragment() {
    }

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

        if (view != null) {
            ViewGroup parent = (ViewGroup) view.getParent();
            if (parent != null)
                parent.removeView(view);
        }


        File file = new File( Environment.getExternalStorageDirectory() + "/json.txt");
            if(file.exists()) {
                try{
                       Reader inputStreamReader = new InputStreamReader(new FileInputStream(file));

                       Gson gson = new Gson();
                       this.response = gson.fromJson(inputStreamReader, Response.class);
                    } catch (FileNotFoundException e) {
                       e.printStackTrace();
                    } catch (@SuppressWarnings("hiding") IOException e){
                       e.printStackTrace();
                    }
            }else{
                System.out.println("Error");
            }

        try {
            view = inflater.inflate(R.layout.map_near_me, container,
                    false);

            mapFragment = ((MapFragment) this.getActivity()
                    .getFragmentManager().findFragmentById(R.id.map));

            map = mapFragment.getMap();
            map.getUiSettings().setAllGesturesEnabled(true);
            map.getUiSettings().setMyLocationButtonEnabled(true);
            map.setMyLocationEnabled(true);
            map.getUiSettings().setZoomControlsEnabled(true);

            for(Shop shop : this.response.shops){
                for(int i = 0; i < shop.getShopLat().size(); i++){

                    map.addMarker(new MarkerOptions().position(new LatLng(Double.parseDouble(shop.getShopLat().get(i)), Double.parseDouble(shop.getShopLng().get(i)))).title(shop.getName()));
                }
            }
            MapsInitializer.initialize(this.getActivity());
        } catch (GooglePlayServicesNotAvailableException e) {
            Toast.makeText(getActivity(), "Google Play Services missing !",
                    Toast.LENGTH_LONG).show();
        } catch (InflateException e) {
            Toast.makeText(getActivity(), "Problems inflating the view !",
                    Toast.LENGTH_LONG).show();
        } catch (NullPointerException e) {
            Toast.makeText(getActivity(), "Google Play Services missing !",
                    Toast.LENGTH_LONG).show();
        }

        return view;
        }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        lr = LocationRequest.create();
        lr.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        lc = new LocationClient(this.getActivity().getApplicationContext(), this, this);
        lc.connect();
    }

    @Override
    public void onLocationChanged(Location l2) {
        CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(new LatLng(l2.getLatitude(), l2.getLongitude()), 15);
        map.animateCamera(cameraUpdate);
    }

    @Override
    public void onConnectionFailed(ConnectionResult arg0) {

    }

    @Override
    public void onConnected(Bundle connectionHint) {
        lc.requestLocationUpdates(lr, this);

    }

    @Override
    public void onDisconnected() {

    }
}

此代码运行良好，但需要时间加载。我认为我的问题可以通过使用一些if语句来解决。但无法弄清楚如何。有人可以帮我解决吗？此外，当我发布这个活动/片段时，我看到非洲的其他一些国家。如何更改为英国默认设置？

Answer 1

这可能会对您有所帮助：

http://mobile.tutsplus.com/tutorials/android/android-sdk-working-with-google-maps-displaying-places-of-interest/

从教程的第3页开始。另外，查看该人已经实现的查询字符串：

String placesSearchStr = "https://maps.googleapis.com/maps/api/place/nearbysearch/" +
                "json?location="+lat+","+lng+
                "&radius=1000&sensor=true" +
                "&key=AIzaSyAXxxoI2aDYyXTUdu3eOTXayrOcWB6F-_I";//ADD KEY

根据您的需要更改半径。请注意，半径值以METERS表示。所以你5英里的价值就像8046.72（根据谷歌，不确定小数位是否有效）。

我希望这可以提供帮助。

Answer 2

我认为您可以使用Location类的distanceTo（）或distanceBetween（）方法来查找每个商店与当前位置之间的距离。在Shop循环中的if语句中使用它。

如何在距离当前位置5英里范围内的json的谷歌地图（纬度和长度）上加载位置

2 个答案: