android - 通过 Android Google API 获取经纬度

Question

我想创建一个可以在每个时间段内为我提供纬度和经度的 android 应用程序。我了解了新的 Android API 以及如何获取最后一个位置，但我仍然不知道如何使用它。我尝试使用 Google API 来获取最后一个位置，但它不起作用。这是我的代码：

import android.location.Location;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.GoogleApiClient.ConnectionCallbacks;
import com.google.android.gms.common.api.GoogleApiClient.OnConnectionFailedListener;
import com.google.android.gms.location.LocationServices;


 public class MainActivity extends ActionBarActivity
 implements ConnectionCallbacks, OnConnectionFailedListener {

 private GoogleApiClient mGoogleApiClient;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

protected synchronized void buildGoogleApiClient() {
    mGoogleApiClient = new GoogleApiClient.Builder(this)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .addApi(LocationServices.API)
            .build();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@Override
public void onConnected(Bundle bundle) {
    Location mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
            mGoogleApiClient);
    if (mLastLocation != null) {
        Log.d("mLatitudeText", String.valueOf(mLastLocation.getLatitude()));
        Log.d("mLatitudeText", String.valueOf(mLastLocation.getLongitude()));

    }
}




@Override
public void onConnectionSuspended(int i) {

}

@Override
public void onConnectionFailed(ConnectionResult connectionResult) {

}

您能告诉我使用 google api 的最佳方式是什么吗？是否有任何其他 API 可以为我提供位置。提前致谢，

Answer 1

首先将其包含在您的 gradle 应用程序中的依赖项下

    compile 'com.google.android.gms:play-services:7.8.0'

然后导入如下

import android.bluetooth.BluetoothAdapter;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.design.widget.Snackbar;
import android.support.v4.app.Fragment;
import android.support.v4.content.ContextCompat;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.widget.RecyclerView;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;
public class OffersFragment extends Fragment {
  GoogleMap map;
    LatLngBounds visibleLatLngBounds;
    LatLng coordinate;
    int distanceAway = 5000;
public OffersFragment(){}
@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_offers, container, false);


        MapsInitializer.initialize(getActivity());

        realm = Realm.getInstance(getActivity());

        setupMap(savedInstanceState);

        recyclerView.setLayoutManager(new WrappingLinearLayoutManager(getActivity()));
        recyclerView.setNestedScrollingEnabled(false);
        recyclerView.setHasFixedSize(false);

        swipeRefreshLayout.setColorSchemeResources(R.color.color_primary, R.color.color_accent);

        swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                refreshOffers();
            }
        });

        ArrayAdapter<CharSequence> kmArrayAdapter = ArrayAdapter
                .createFromResource(this.getContext(), R.array.string_array_kilometers_away,
                        android.R.layout.simple_spinner_item);

        kmArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        kmRangeSpinner.setAdapter(kmArrayAdapter);

        kmRangeSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                map.clear();
                if (coordinate != null) {
                    if (id == 0) setDistanceAway(5000);
                    else if (id == 1) setDistanceAway(10000);
                    else if (id == 2) setDistanceAway(20000);
                    else if (id == 3) setDistanceAway(50000);
                    else if (id == 4) setDistanceAway(200000);
                }
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                int id = parent.getId();

                if (id == 0) setDistanceAway(5000);
                else if (id == 1) setDistanceAway(10000);
                else if (id == 2) setDistanceAway(20000);
                else if (id == 3) setDistanceAway(50000);
                else if (id == 4) setDistanceAway(200000);
            }
        });

        ArrayAdapter<CharSequence> categoriesAdapter = ArrayAdapter
                .createFromResource(this.getContext(), R.array.string_array_offer_categories,
                        android.R.layout.simple_spinner_item);

        categoriesAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        categoriesSpinner.setAdapter(categoriesAdapter);

        categoriesSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                if(visibleLatLngBounds!=null){
                    try {
                        map.clear();
                        loadOffers();
                    } catch (ParseException e) {
                        e.printStackTrace();
                    }
                }
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });

        return view;
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        // Check if device supports Bluetooth Low Energy.
        if (!beaconManager.hasBluetooth()) {
            Toast.makeText(getActivity(), "Device does not have Bluetooth Low Energy", Toast.LENGTH_LONG).show();
            return;
        }

        // If Bluetooth is not enabled, let user enable it.
        if (!beaconManager.isBluetoothEnabled()) {
            Snackbar.make(view, "Open Bluetooth Low Energy to discover exclusive offers", Snackbar.LENGTH_LONG).setAction("Discover", new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                    startActivity(enableBtIntent);
                }
            }).show();
        }
    }

    private void setupMap(Bundle savedInstanceState){
        mapView.onCreate(savedInstanceState);

        // Gets to GoogleMap from the MapView and does initialization stuff
        map = mapView.getMap();
        map.getUiSettings().setMyLocationButtonEnabled(false);
        map.setMyLocationEnabled(true);
        map.getUiSettings().setScrollGesturesEnabled(false);
        map.getUiSettings().setTiltGesturesEnabled(false);
        map.getUiSettings().setRotateGesturesEnabled(false);
        map.getUiSettings().setZoomGesturesEnabled(false);

        map.setOnMapLoadedCallback(new GoogleMap.OnMapLoadedCallback() {
            @Override
            public void onMapLoaded() {
                visibleLatLngBounds = map.getProjection()
                        .getVisibleRegion().latLngBounds;
                if (visibleLatLngBounds != null) {
                    try {
                        loadOffers();
                    } catch (ParseException e) {
                        e.printStackTrace();
                    }
                }
            }
        });

        map.setOnCameraChangeListener(new GoogleMap.OnCameraChangeListener() {
            @Override
            public void onCameraChange(CameraPosition cameraPosition) {
                visibleLatLngBounds = map.getProjection()
                        .getVisibleRegion().latLngBounds;
                if (visibleLatLngBounds != null) {
                    try {
                        loadOffers();
                    } catch (ParseException e) {
                        e.printStackTrace();
                    }
                }
            }
        });

        map.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
            @Override
            public void onMyLocationChange(Location location) {
                double lat =  location.getLatitude();
                double lng = location.getLongitude();
                coordinate = new LatLng(lat, lng);

                // Updates the location and zoom of the MapView
                animateToLocation(coordinate, getDistanceAway());
                map.setOnMyLocationChangeListener(null);
            }
        });

        // Needs to call MapsInitializer before doing any CameraUpdateFactory calls
        MapsInitializer.initialize(this.getActivity());

        Criteria criteria = new Criteria();
        LocationManager locationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);
        String provider = locationManager.getBestProvider(criteria, false);

        if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

            requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION},MY_LOCATION_REQUEST_CODE);

        }
        else{
            map.setMyLocationEnabled(true);
        }

        if (locationManager.getLastKnownLocation(provider)!=null){
            Location location = locationManager.getLastKnownLocation(provider);
            double lat =  location.getLatitude();
            double lng = location.getLongitude();
            coordinate = new LatLng(lat, lng);

            // Updates the location and zoom of the MapView
            animateToLocation(coordinate, getDistanceAway());
        }

        else{
            //Zoom in to Nairobi
            coordinate = new LatLng(-1.277001, 36.816498);
            animateToLocation(coordinate, getDistanceAway());
        }


//        Marker galleria = map.addMarker(new MarkerOptions().position(GALLERIA)
//                .title("Safaricom Shop, Galleria"));
//
//        Marker westgate = map.addMarker(new MarkerOptions().position(WESTGATE)
//                .title("Safaricom Shop, Westgate"));


    }

    public void loadOffers() throws ParseException {

        RealmResults<Offer> offers;

        if(categoriesSpinner.getSelectedItemId()==0){
            offers = realm.where(Offer.class).between(Offer.VARIABLE_LATITUDE,visibleLatLngBounds.southwest.latitude,visibleLatLngBounds.northeast.latitude).between(Offer.VARIABLE_LONGITUDE, visibleLatLngBounds.southwest.longitude, visibleLatLngBounds.northeast.longitude).findAll();
        }
        else {
            offers = realm.where(Offer.class).between(Offer.VARIABLE_LATITUDE,visibleLatLngBounds.southwest.latitude,visibleLatLngBounds.northeast.latitude).between(Offer.VARIABLE_LONGITUDE, visibleLatLngBounds.southwest.longitude, visibleLatLngBounds.northeast.longitude).equalTo(Offer.VARIABLE_CATEGORY,categoriesSpinner.getSelectedItemId()).findAll();
        }

        Log.d(LOG_TAG, "NorthEast latlng:"+visibleLatLngBounds.northeast.latitude+" "+visibleLatLngBounds.northeast.longitude+"SouthWest latlng:"+visibleLatLngBounds.southwest.latitude+" "+visibleLatLngBounds.southwest.longitude);
        offersAdapter = new OffersAdapter(getActivity(), offers);
        recyclerView.setAdapter(offersAdapter);

        for(Offer offer: offers){
            map.addMarker(new MarkerOptions().position(new LatLng(offer.getStore().getLatitude(), offer.getStore().getLongitude())).title(offer.getStore().getName()));
        }

    }
    public void refreshOffers(){

        String urlJsonArray = "************/viewjsonshopoffers.php";
        request = new JsonArrayRequest(urlJsonArray,
                new Response.Listener<JSONArray>() {
                    @Override
                    public void onResponse(JSONArray response) {
                        Log.d(LOG_TAG, response.toString());
                        swipeRefreshLayout.setRefreshing(false);
                        try {

                            realm.beginTransaction();

                            realm.clear(Offer.class);

                            realm.commitTransaction();

                            for (int i = 0; i < response.length(); i++) {

                                JSONObject jsonResponse = (JSONObject) response.get(i);

                                int storeId = jsonResponse.getInt("shop_id");
                                String storeName = jsonResponse.getString("shop_name");
                                String storeStreetName = jsonResponse.getString("shop_streetname");
                                String storeStreetDesc = jsonResponse.getString("shop_streetdesc");
                                String storeCity = jsonResponse.getString("shop_city");
                                double storeLatitude = jsonResponse.getDouble("shop_latitude");
                                double storeLongitude = jsonResponse.getDouble("shop_longitude");

                                Store store = new Store(storeId, storeName, storeStreetName, storeStreetDesc, storeCity, storeLatitude, storeLongitude);

                                int offerId = jsonResponse.getInt("offer_id");
                                String offerName = jsonResponse.getString("offer_name");
                                String offerPriceDescription = jsonResponse.getString("offer_string_price_description");
                                int offerPrice = jsonResponse.getInt("offer_int_price");
                                String offerDescription = jsonResponse.getString("offer_description");
                                String offerNotificationMessage = jsonResponse.getString("offer_notification_message");
                                Date offerDateDue = DateUtils.getDateInMillis(jsonResponse.getString("offer_datedue"));
                                int offerKeyword = jsonResponse.getInt("offer_keyword");
                                int offerBeaconMajor = jsonResponse.getInt("offer_beacon_major");
                                String offerImageUrl = jsonResponse.getString("offer_url");

                                Offer offer = new Offer(offerId, offerName, offerPriceDescription, offerPrice, offerDescription, offerNotificationMessage, offerDateDue, store, offerKeyword, offerBeaconMajor, offerImageUrl);

                                realm.beginTransaction();

                                realm.copyToRealmOrUpdate(offer);

                                realm.commitTransaction();

                                map.clear();

                                loadOffers();

                            }

                        } catch (JSONException e) {
                            e.printStackTrace();
                        } catch (ParseException e) {
                            e.printStackTrace();
                        }
                    }

                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                VolleyLog.d(LOG_TAG, "Error: " + error.getMessage());
                swipeRefreshLayout.setRefreshing(false);
                error.printStackTrace();
            }

        });

        AppController.getInstance().addToRequestQueue(request, LOG_TAG);
    }

    private void animateToLocation(LatLng coordinate, int meters) {
        DisplayMetrics displaymetrics = new DisplayMetrics();
        if(getActivity().getWindowManager()!=null){
            getActivity().getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
            int width = displaymetrics.widthPixels;
            int metersRecalculate = meters *10;

            double equatorLength = 40075004; // in meters
            double widthInPixels = width;
            double metersPerPixel = equatorLength / 256;
            int zoomLevel = 1;
            while ((metersPerPixel * widthInPixels) > metersRecalculate) {
                metersPerPixel /= 2;
                ++zoomLevel;
            }

            CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(coordinate, zoomLevel);
            map.animateCamera(cameraUpdate);
        }


    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == MY_LOCATION_REQUEST_CODE) {
            if (permissions.length == 1 &&
                    permissions[0] == Manifest.permission.ACCESS_FINE_LOCATION &&
                    grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                map.setMyLocationEnabled(true);
            } else {
                // Permission was denied. Display an error message.
            }

        }
    }

    public int getDistanceAway() {
        return distanceAway;
    }

    public void setDistanceAway(int distanceAway) {
        this.distanceAway = distanceAway;
        animateToLocation(coordinate, this.distanceAway);
    }

    @Override
    public void onResume() {
        mapView.onResume();
        super.onResume();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mapView.onDestroy();
        if(request!=null){
            request.cancel();
        }
    }

    @Override
    public void onLowMemory() {
        super.onLowMemory();
        mapView.onLowMemory();
    }

}

我没有编辑太多，因为这个项目有一个场景 f 找到当前位置，并要求用户在获取用户的最后一个位置时更新他的位置。

对于那些使用 Realm 的人也可以从这个项目中受益，其中 Realm 与地图一起使用