Android在Google Maps Android API V2中获得当前位置作为起点

Question

我正在尝试创建从当前位置到方向的路由，现在我可以使用固定的纬度和经度，但如何使用我当前的位置。这是我的文件:

public class DirectionActivity3 extends FragmentActivity {

TextView textProgress;
Button buttonAnimate, buttonRequest;
double mLatitude=0;
double mLongitude=0;
GoogleMap mMap;
GoogleDirection gd;
Document mDoc;

LatLng start = new LatLng(mLatitude,mLongitude);
LatLng end = new LatLng(3.158847, 101.713837);

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_direction_1);
    mMap = ((SupportMapFragment)getSupportFragmentManager()
            .findFragmentById(R.id.map)).getMap();
    mMap.setMyLocationEnabled(true);

    mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(start, 15));
    gd = new GoogleDirection(this);
    gd.setOnDirectionResponseListener(new OnDirectionResponseListener() {
        public void onResponse(String status, Document doc, GoogleDirection gd) {
            mDoc = doc;
            mMap.addPolyline(gd.getPolyline(doc, 3, Color.RED));    
            buttonAnimate.setVisibility(View.VISIBLE);
        }
    });
    gd.setOnAnimateListener(new OnAnimateListener() {
        public void onStart() {
            textProgress.setVisibility(View.VISIBLE);
        }
        public void onProgress(int progress, int total) {
            textProgress.setText((int)((float)progress / total * 100) + "% / 100%");
        }
        public void onFinish() {
            buttonAnimate.setVisibility(View.VISIBLE);
            textProgress.setVisibility(View.GONE);
        }
    });
    textProgress = (TextView)findViewById(R.id.textProgress);
    textProgress.setVisibility(View.GONE);
    buttonRequest = (Button)findViewById(R.id.buttonRequest);
    buttonRequest.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            v.setVisibility(View.GONE);
            gd.setLogging(true);
            gd.request(start, end, GoogleDirection.MODE_DRIVING);
        }
    });
    buttonAnimate = (Button)findViewById(R.id.buttonAnimate);
    buttonAnimate.setVisibility(View.GONE);
    buttonAnimate.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            v.setVisibility(View.GONE);
            gd.animateDirection(mMap, gd.getDirection(mDoc), GoogleDirection.SPEED_VERY_SLOW
                    , true, false, true, true
                    , new MarkerOptions().icon(BitmapDescriptorFactory.fromResource(R.drawable.car))
                    , true, false, null);
        }
    });
}
public void onPause() {
    super.onPause();
    gd.cancelAnimated();
}

}

还有一个问题，我想使用Google Place API获取某地的经纬度作为方向，并使用我当前的位置来创建路由。

这是我的方向文件:

public class PlaceActivity3 extends Activity {
final String ApiKey = "AIzaSyDQ6mA6vUHD3cMNqDoblES6q3dFHzNLqs4";
double latitude = 3.158847;
double longitude = 101.713837;
int radius = 1000;
String type = PlaceType.FOOD;
String language = "en";
String keyword = "japan restaurant food";
TextView textStatus;
ListView listView;
GooglePlaceSearch gp;
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_place_1);
    textStatus = (TextView)findViewById(R.id.textStatus);
    listView = (ListView)findViewById(R.id.listView);
    gp = new GooglePlaceSearch(ApiKey);
    gp.setOnPlaceResponseListener(new OnPlaceResponseListener() {
        public void onResponse(String status, ArrayList<ContentValues> arr_data,
                Document doc) {
            textStatus.setText("Status : " + status);
            if(status.equals(GooglePlaceSearch.STATUS_OK)) {
                ArrayList<String> array = new ArrayList<String>();
                final ArrayList<String> array_photo = new ArrayList<String>();
                for(int i = 0 ; i < arr_data.size() ; i++) {
                    array.add("Name : " + arr_data.get(i).getAsString(GooglePlaceSearch.PLACE_NAME) + "n"
                            + "Address : " + arr_data.get(i).getAsString(GooglePlaceSearch.PLACE_ADDRESS) + "n"
                            + "Latitude : " + arr_data.get(i).getAsString(GooglePlaceSearch.PLACE_LATITUDE) + "n"
                            + "Longitude : " + arr_data.get(i).getAsString(GooglePlaceSearch.PLACE_LONGITUDE) + "n"
                            + "Phone Number : " + arr_data.get(i).getAsString(GooglePlaceSearch.PLACE_PHONENUMBER));
                    array_photo.add(arr_data.get(i).getAsString(GooglePlaceSearch.PLACE_PHOTO));
                }
                ArrayAdapter<String> adapter = new ArrayAdapter<String>(PlaceActivity3.this
                        , R.layout.listview_text, array);
                listView.setAdapter(adapter);
                listView.setOnItemClickListener(new OnItemClickListener() {
                    public void onItemClick(AdapterView<?> arg0, View arg1,
                            int arg2, long arg3) {
                        Dialog dialog = new Dialog(PlaceActivity3.this);
                        dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
                        dialog.setContentView(R.layout.dialog_photo);
                        dialog.setCancelable(true);
                        final ImageView imgPhoto = (ImageView)dialog.findViewById(R.id.imgPhoto);
                        dialog.show();
                        gp.getPhotoBitmapByWidth(array_photo.get(arg2), 600, ""
                                , new OnBitmapResponseListener() {
                            public void onResponse(Bitmap bm, String tag) {
                                imgPhoto.setImageBitmap(bm);
                            }
                        });
                    }
                });
            }
        }
    });
    gp.getNearby(latitude, longitude, radius, type, language, keyword);
}

}

Answer 1

对于当前位置，可以使用LocationServices的getLastLocation()函数:它应该看起来像这样:

public class MainActivity extends ActionBarActivity implements
        ConnectionCallbacks, OnConnectionFailedListener {
    ...
    @Override
    public void onConnected(Bundle connectionHint) {
        mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
                mGoogleApiClient);
        if (mLastLocation != null) {
            mLatitudeText.setText(String.valueOf(mLastLocation.getLatitude()));
            mLongitudeText.setText(String.valueOf(mLastLocation.getLongitude()));
        }
    }
}

https://developer.android.com/training/location/retrieve-current.html最后为人所知

或者，你可以使用谷歌地图的位置数据API:https://developers.google.com/maps/documentation/android/location

对于你的目的地的lat/lng，你应该使用Google Geocoding API:https://developers.google.com/maps/documentation/geocoding/GeocodingResponses