我正在研究在线租车搜索apk。我希望这个程序从服务器获取数据库并根据位置（与用户当前租车车库位置的距离）对其进行排序。 但我在这里混淆如何根据距离对列表视图进行排序？我的意思是，我知道如何计算距离，但我对于如何在不打开mapActivity的情况下获取用户当前的经度和经度感到空白？ 这是我现在的状况： 1.我的结果列表在ResultListFragment.java中，我的谷歌地图活动在MapActivity.java上。 2.我必须尝试使用我在MapActivity.java上创建的getLatitude和getLongitude方法获取经度，纬度，但它只返回零（非空）。 3.我试图在GPStracker类上分离gps监听器，但它仍无效。
请帮助我，我如何获得当前用户位置的纬度和经度。
NB。这是我的ResultListFragment.java
public class ResultListFragment extends Fragment implements InternetConnectionListener,
LocationChangeListener {
public static String catId;
public static String titleId;
public static String searchTerm;
public static LocationChangeListener locationChangeListener;
private final int RESULT_ACTION = 1;
private final int RESULT_LIMIT = 100;
private ArrayList<Item> searchResultList;
private ResultListCallbacks mCallbacks;
private InternetConnectionListener internetConnectionListener;
private ArrayList<Item> resultList;
private ListView resultListView;
private LatLng itemLocation;
GPSTrackStandAlone gTrack = new GPSTrackStandAlone(getContext());
MapActivity mAct = new MapActivity();
public HomeActivity hAct = new HomeActivity();
public ResultListFragment() {
}
public static ResultListFragment newInstance(String id, String title) {
ResultListFragment fragment = new ResultListFragment();
catId = id;
titleId = title;
searchTerm = "";
locationChangeListener = fragment;
return fragment;
}
public static ResultListFragment newInstance(String id, String title,String term) {
ResultListFragment fragment = new ResultListFragment();
catId = id;
titleId = title;
searchTerm = term;
locationChangeListener = fragment;
return fragment;
}
public void getGPSLoc(){
double latitude = mAct.getLatitudeSend();
double longitude = mAct.getLongitudeSend();
Log.d("LatitudeCurrGPSLoc",String.valueOf(latitude));
Log.d("LongCur",String.valueOf(longitude));
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mCallbacks = (ResultListCallbacks) activity;
} catch (ClassCastException e) {
throw new ClassCastException("Activity must implement ResultListCallbacks.");
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_result_list, container, false);
resultListView = (ListView) rootView.findViewById(R.id.resultListView);
setHasOptionsMenu(true);
return rootView;
}
@Override
public void onResume() {
super.onResume();
isHomeOpened = false;
isResultListFragmentOpened = true;
if (UtilMethods.isConnectedToInternet(getActivity())) {
if (!TextUtils.isEmpty(catId))
initResultList();
else if (!TextUtils.isEmpty(searchTerm))
getSearchResults(searchTerm);
} else {
internetConnectionListener = (InternetConnectionListener) ResultListFragment.this;
showNoInternetDialog(getActivity(), internetConnectionListener, getResources().getString(R.string.no_internet),
getResources().getString(R.string.no_internet_text),
getResources().getString(R.string.retry_string),
getResources().getString(R.string.exit_string), RESULT_ACTION);
}
}
private void initResultList() {
Log.d("Pembuktian", catId);
if(Integer.parseInt(catId)>100 && Integer.parseInt(catId)<200 ){
new getCarRent().execute();
}else if(Integer.parseInt(catId)>199 && Integer.parseInt(catId)<300){
new getCarBrand().execute();
}else if(Integer.parseInt(catId)>299 && Integer.parseInt(catId)<400){
new getCarType().execute();
}
/**
* json is populating from text file. To make api call use ApiHandler class
* pass parameter using ContentValues (values)
*
* <CODE> ApiHandler handler = new ApiHandler(this, URL_GET_RESULT_LIST_WITH_AD, values);</CODE> <BR>
* <CODE> handler.doApiRequest(ApiHandler.REQUEST_POST);</CODE> <BR>
*
* You will get the response in onSuccessResponse(String tag, String jsonString) method
* if successful api call has done.
*/
// String jsonString = loadJSONFromAsset(getActivity(), "get_result_list");
//parseJson(jsonString);
}
private void getSearchResults(String query) {
/**
* json is populating from text file. To make api call use ApiHandler class
* pass parameter using ContentValues (values)
*
* <CODE> ApiHandler handler = new ApiHandler(this, URL_GET_SEARCH_LIST_AD, values);</CODE> <BR>
* <CODE> handler.doApiRequest(ApiHandler.REQUEST_POST);</CODE> <BR>
*
* You will get the response in onSuccessResponse(String tag, String jsonString) method
* if successful api call has done.
*/
String jsonString = loadJSONFromAsset(getActivity(), "get_search_list");
parseJson(jsonString);
}
public class getCarRent extends AsyncTask<Void, Void, Void>{
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected Void doInBackground(Void... params) {
URL hp = null;
try {
hp = new URL(getString(R.string.liveurl)
+ "getCarRent.php?value=" + catId);
// hp = new URL(
// "http://192.168.1.106/restourant/foodtype.php?value="
// + id);
Log.d("URL", "" + hp);
URLConnection hpCon = hp.openConnection();
hpCon.connect();
InputStream input = hpCon.getInputStream();
Log.d("input", "" + input);
BufferedReader r = new BufferedReader(new InputStreamReader(
input));
String x = "";
x = r.readLine();
String total = "";
while (x != null) {
total += x;
x = r.readLine();
}
Log.d("URL", "" + total);
JSONArray j = new JSONArray(total);
Log.d("URL1", "" + j.length());
Item[] itemList = new Item[j.length()];
resultList = new ArrayList<Item>();
for (int i = 0; i < j.length(); i++) {
Item item = new Item();// buat variabel category
//JSONObject Obj;
JSONObject Obj = j.getJSONObject(i); //sama sperti yang lama, cman ini lebih mempersingkat karena getJSONObject cm d tulis sekali aja disini
item.setId(Obj.getString(JF_ID));
//item.setTitle(Obj.getString(JF_TITLE));
item.setAddress(Obj.getString(JF_ADDRESS));
item.setTelephoneNumber(Obj.optString(JF_TELEPHONE, NO_DATA_FOUND));
item.setEmailAddress(Obj.optString(JF_EMAIL, NO_DATA_FOUND));
item.setWebUrl(Obj.optString(JF_WEB, NO_DATA_FOUND));
item.setFacebookUrl(Obj.optString(JF_FACEBOOK, NO_DATA_FOUND));
item.setLatitude(Obj.optDouble(JF_LATITUDE, NULL_LOCATION));
item.setLongitude(Obj.optDouble(JF_LONGITUDE, NULL_LOCATION));
try {
item.setRating(Float.parseFloat(Obj.optString(JF_RATING, NO_DATA_FOUND)));
} catch (NumberFormatException e) {
item.setRating(0.0f);
}
try {
item.setRatingCount(Integer.parseInt(Obj.optString(JF_RATING_COUNT, NO_DATA_FOUND)));
} catch (NumberFormatException e) {
item.setRatingCount(0);
}
try {
item.setRatingCount(Integer.parseInt(Obj.optString(JF_RATINGSCORE, NO_DATA_FOUND)));
} catch (NumberFormatException e) {
item.setRatingCount(0);
}
item.setTagLine(Obj.optString(JF_TAG_LINE, NO_DATA_FOUND));
item.setDescription(Obj.optString(JF_DESCRIPTION, NO_DATA_FOUND));
item.setVerification(Obj.optString(JF_VERIFICATION, NO_DATA_FOUND).equals("1") ? true : false);
item.setCarId(Obj.optString(JF_CARID, NO_DATA_FOUND));
item.setTitle(Obj.optString(JF_CARTITLE, NO_DATA_FOUND));
item.setCarRentalId(Obj.optString(JF_CARRENTALID, NO_DATA_FOUND));
item.setCarPrice(Obj.optString(JF_CARPRICE, NO_DATA_FOUND));
item.setCarYear(Obj.optString(JF_CARYEAR, NO_DATA_FOUND));
JSONArray imgArr = Obj.getJSONArray("thumbImage");
String[] imageThumb = new String[imgArr.length()];
// String[] imageLarge = new String[imgArr.length()];
for (int k = 0; k < imgArr.length(); k++) {
imageThumb[k] = imgArr.getString(k);
// imageLarge[k] = imgArr.getJSONObject(k).getString(JF_TITLE);
}
for(int l = 0; l <imgArr.length(); l++) {
item.setImageLargeUrls(imageThumb);
}
item.setImageThumbUrls(imageThumb);
// item.setImageLargeUrls(imageLarge);
// JSONArray imgArr = Obj.getJSONArray("thumbImage");
/*String[] imgCount = new String[imgArr.length()];
for(int k = 0 ; k < imgCount.length; k++) {
imgCount[k] = imgArr.getString(k);
item.setImageThumbUrls(imgCount);
}*/
Location trgtLocation = new Location("trgtLocation");
trgtLocation.setLatitude(item.getLatitude());
trgtLocation.setLongitude(item.getLongitude());
Location crntLocation = new Location("crntlocation");
crntLocation.setLatitude(gTrack.getLatitude());
crntLocation.setLongitude(gTrack.getLongitude());
Log.d("latitudeCurr", String.valueOf(gTrack.getLatitude()));
Log.d("curLocLong", String.valueOf(gTrack.getLongitude()));
//LatLng currentLatLng = new LatLng(mCurrentLocation.getLatitude(), mCurrentLocation.getLongitude());
item.setDistance(crntLocation.distanceTo(trgtLocation) / 1000);
Log.d("distance", String.valueOf(item.getDistance()));
Log.d("URL1", "" + Obj.getString(JF_TITLE));
resultList.add(item);
itemList[i]=item;
Log.d("itemList",String.valueOf(itemList[i]));
Arrays.sort(itemList, new Comparator<Item>() {
@Override
public int compare(Item lhs, Item rhs) {
return 0;
}
});
}
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
resultListView.setAdapter(new ResultListAdapterRental(getActivity(), mCallbacks, resultList));
}
});
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NullPointerException e) {
// TODO: handle exception
}
return null;
}
}
我尝试从像这样的系统服务中获取Lng和Lat，但它仍然不起作用。这段代码对吗？
GPSTracker.java
public class GPSTrackStandAlone extends Service implements LocationListener {
private LocationRequest mLocationRequest;
private GoogleApiClient mGoogleApiClient;
private Context mContext;
private boolean isGpsEnabled = false;
private boolean isNetworkEnabled = false;
private boolean canGetLocation = false;
private Location mLocation;
private double mLatitude;
private double mLongitude;
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATE = 10;
private static final long MIN_TIME_FOR_UPDATE = 60000;
private LocationManager mLocationManager;
private static final long INTERVAL = 1000 * 10;
private static final long FASTEST_INTERVAL = 1000 * 5;
public GPSTrackStandAlone(Context mContext) {
this.mContext = mContext;
}
/**
* @return location
*/
public Location getLocation() {
try {
mLocationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);
/*getting status of the gps*/
isGpsEnabled = mLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
/*getting status of network provider*/
isNetworkEnabled = mLocationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGpsEnabled && !isNetworkEnabled) {
/*no location provider enabled*/
} else {
this.canGetLocation = true;
/*getting location from network provider*/
if (isNetworkEnabled) {
if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
|| ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
mLocationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_FOR_UPDATE,
MIN_DISTANCE_CHANGE_FOR_UPDATE, this);
Log.d("Perms", "Permission for GPS Granted");
if (mLocationManager != null) {
mLocation = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (mLocation != null) {
mLatitude = mLocation.getLatitude();
mLongitude = mLocation.getLongitude();
}
}
}
/*if gps is enabled then get location using gps*/
if (isGpsEnabled) {
if (mLocation == null) {
mLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_FOR_UPDATE,
MIN_DISTANCE_CHANGE_FOR_UPDATE, this);
Log.d("GPS Enabled", "GPS Enabled");
if (mLocationManager != null) {
mLocation = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (mLocation != null) {
mLatitude = mLocation.getLatitude();
mLongitude = mLocation.getLongitude();
}
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return mLocation;
}
/**
* call this function to stop using gps in your application
*/
public void stopUsingGps() {
if (mLocationManager != null) {
if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
|| ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
mLocationManager.removeUpdates(GPSTrackStandAlone.this);
}
}
}
private boolean isGooglePlayServicesAvailable() {
int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (ConnectionResult.SUCCESS == status) {
return true;
} else {
Toast.makeText(GPSTrackStandAlone.this, "isGooglePlayServiceAvailable = False", Toast.LENGTH_SHORT).show();
return false;
}
}
protected void createLocationRequest() {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(INTERVAL);
mLocationRequest.setFastestInterval(FASTEST_INTERVAL);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}
/**
* @return latitude
* <p/>
* function to get latitude
*/
public double getLatitude() {
getLocation();
if (mLocation != null) {
mLatitude = mLocation.getLatitude();
}
return mLatitude;
}
/**
* @return longitude
* function to get longitude
*/
public double getLongitude() {
getLocation();
if (mLocation != null) {
mLongitude = mLocation.getLongitude();
Log.d("MGPS", String.valueOf(mLocation.getLatitude()));
}
return mLongitude;
}
/**
* @return to check gps or wifi is enabled or not
*/
public boolean canGetLocation() {
return this.canGetLocation;
}
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
}
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
答案 0 :(得分：0)
您是否考虑过使用Google Maps API？有了它，您只需执行以下操作即可获得用户的当前位置：
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
.getMap();
mMap.setMyLocationEnabled(true);
Location myLocation = googleMap.getMyLocation();
答案 1 :(得分：0)
您的意思是您可以getLng和getLat参加活动吗？
尝试使用public static来描述您的值，并在片段中使用MyActivity.value。
答案 2 :(得分：0)
如果要将数据从活动传递到片段，则应使用bundle。 我会举个例子。
public class CompleteJobFragment extends Fragment {
private final static String PICKUP_TIME="pickup time";
public static CompleteJobFragment newInstance(String pickUpTime) {
CompleteJobFragment fragment = new CompleteJobFragment();
Bundle bundle = new Bundle();
bundle.putString(PICKUP_TIME, pickUpTime);
fragment.setArguments(bundle);
return fragment;
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
pickUpTime = getArguments().getString(PICKUP_TIME);
}
}
活动文件
public class ActiveJobActivity extends AppCompatActivity {
String x1;
public void loadData()
{
CompleteJobFragment completeJobFragment = CompleteJobFragment.newInstance(x1);
final FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.activez, completeJobFragment, COMPLETE_FRAGMENT);
fragmentTransaction.addToBackStack(COMPLETE_FRAGMENT);
completeJobFragment.setCommunicator(this);
fragmentTransaction.commit();
}