我有一张 map ，我想在上面显示用户的当前位置，并且在获取用户的位置后调用 api 来获取附近的商家。
我正在获取用户的当前位置，所有商家也都通过 map 上的标记来获取位置。
但是我在LocationListener的onLocationChanged()方法中调用了setMap方法。该方法会被连续调用。
我想获取一次位置并显示在标记上，当下次用户访问此 fragment 时，我只想获取更新的位置。
但现在它会连续循环调用 onLocation 方法，因此会调用 accessMerchants。
为了阻止这个问题，我尝试从位置管理器中删除更新，我还尝试设置一个 boolean 变量，如果它第一次进入 onLocationChanged() 方法，它将是 false，但它也会再次进入循环。
删除更新也不起作用，如果删除更新起作用，那么 onLocationChanged 方法不应该再次被调用，对吗？
public class SearchMerchantFragment extends Fragment implements GetSearchedMerchantsAsyncTask.GetSearchedMerchantsCallBack, OnMapReadyCallback, GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener {
LocationListener[] mLocationListeners = new LocationListener[]{
new LocationListener(LocationManager.GPS_PROVIDER),
new LocationListener(LocationManager.NETWORK_PROVIDER)
};
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_search_merchant, container, false);
setUpUI(view);
return view;
}
public void setUpUI(View view) {
initializeLocationManager();
requestLocation();
setUpMapIfNeeded();
mLocationsList = new ArrayList<>();
markers = new ArrayList<>();
edtSearch = (EditText) view.findViewById(R.id.edtSearch);
rv_fetch_merchants = (RecyclerView) view.findViewById(R.id.rv_fetch_merchants);
merchantsList = new ArrayList<Merchants>();
merchantsAdapter = new SearchedMerchantsAdapter(this.getContext(), merchantsList);
rv_fetch_merchants.setLayoutManager(new LinearLayoutManager(getActivity()));
rv_fetch_merchants.setAdapter(merchantsAdapter);
rv_fetch_merchants.setHasFixedSize(true);
rv_fetch_merchants.setItemViewCacheSize(30);
rv_fetch_merchants.setDrawingCacheEnabled(true);
rv_fetch_merchants.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);
}
//get searched merchants
public void accessMerchants() {
if (CommonUtils.isConnectedToInternet(getContext())) {
new GetSearchedMerchantsAsyncTask(getActivity(), SearchMerchantFragment.this).execute(access_token, sessionUserId, String.valueOf(mLastLocation.getLatitude()), String.valueOf(mLastLocation.getLongitude()));
} else {
showAlert(String.valueOf(R.string.check_network));
}
}
@Override
public void doPostExecute(ArrayList<Merchants> merchantsArrayList) {
merchantsList.clear();
merchantsList.addAll(merchantsArrayList);
merchantsAdapter.notifyDataSetChanged();
for (Merchants merchants : merchantsList) {
LatLng latLng = new LatLng(merchants.getLatitude(), merchants.getLongitude());
MarkerOptions marker = new MarkerOptions().position(latLng).icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED)).title(merchants.getKirana_name());
Marker m = mGoogleMap.addMarker(marker);
markers.add(m);
}
}
private void setUpMapIfNeeded() {
if (mGoogleMap == null) {
mapFragment = (SupportMapFragment) getChildFragmentManager().findFragmentById(R.id.map_fragment);
mapFragment.getMapAsync(this);
// getLocation();
}
}
//setup map
@Override
public void onMapReady(GoogleMap googleMap) {
mGoogleMap = googleMap;
buildGoogleApiClient();
mGoogleApiClient.connect();
}
protected synchronized void buildGoogleApiClient() {
// Toast.makeText(getActivity(),"buildGoogleApiClient",Toast.LENGTH_SHORT).show();
mGoogleApiClient = new GoogleApiClient.Builder(getActivity())
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
}
@Override
public void onConnected(Bundle bundle) {
// Toast.makeText(getActivity(),"onConnected",Toast.LENGTH_SHORT).show();
}
@Override
public void onConnectionSuspended(int i) {
// Toast.makeText(getActivity(),"onConnectionSuspended",Toast.LENGTH_SHORT).show();
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
// Toast.makeText(getActivity(),"onConnectionFailed",Toast.LENGTH_SHORT).show();
}
private void removeMarkers() {
if (mGoogleMap != null) {
for (Marker marker : markers) {
marker.remove();
}
mGoogleMap.clear();
markers.clear();
}
}
@Override
public void onDetach() {
super.onDetach();
mapConnected = false;
}
return true;
}
public void setMap() {
try {
int locationPermission = ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.ACCESS_FINE_LOCATION);
int coarseLocation = ContextCompat.checkSelfPermission(getActivity(),Manifest.permission.ACCESS_COARSE_LOCATION);
if(locationPermission == PackageManager.PERMISSION_GRANTED && coarseLocation == PackageManager.PERMISSION_GRANTED && GPSTracker.isGPSEnabled) {
if(receivedLocation) {
receivedLocation = false;
mLatLang = new LatLng(mLastLocation.getLatitude(), mLastLocation.getLongitude());
accessMerchants();
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(mLatLang);
markerOptions.title(getString(R.string.position));
markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE));
mMarker = mGoogleMap.addMarker(markerOptions);
CameraPosition cameraPosition = new CameraPosition.Builder().target(mLatLang).zoom(14).build();
mGoogleMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
// mLocationRequest = new LocationRequest();
// mLocationRequest.setInterval(5000); //5 seconds
// mLocationRequest.setFastestInterval(3000); //3 seconds
// mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
mGoogleMap.setMyLocationEnabled(true);
mGoogleMap.getUiSettings().setZoomControlsEnabled(true);
mGoogleMap.getUiSettings().setAllGesturesEnabled(true);
LocationListener locationListener = new LocationListener();
mLocationManager.removeUpdates(locationListener);
}
}
else {
showAlert(getString(R.string.locationAlert));
}
} catch (SecurityException e) {
}
}
private void initializeLocationManager() {
// Log.e(Application.TAG, "initializeLocationManager");
if (mLocationManager == null) {
mLocationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);
}
boolean gps_enabled = false;
boolean network_enabled = false;
try {
gps_enabled = mLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
} catch (Exception ex) {
}
try {
network_enabled = mLocationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
} catch (Exception ex) {
}
if (!gps_enabled && !network_enabled) {
// notify user
showAlert(getString(R.string.locationAlert));
}
}
public class LocationListener implements android.location.LocationListener {
public LocationListener() {
}
public LocationListener(String provider) {
Log.e(Application.TAG, "LocationListener " + provider);
mLastLocation = new Location(provider);
}
@Override
public void onLocationChanged(Location location) {
Log.e(Application.TAG, "onLocationChanged: " + location);
receivedLocation = true;
mLastLocation.set(location);
if (receivedLocation) {
setMap();
}
}
@Override
public void onProviderDisabled(String provider) {
Log.e(Application.TAG, "onProviderDisabled: " + provider);
}
@Override
public void onProviderEnabled(String provider) {
Log.e(Application.TAG, "onProviderEnabled: " + provider);
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
Log.e(Application.TAG, "onStatusChanged: " + provider);
}
}
public void requestLocation() {
try {
mLocationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, 0, 0,
mLocationListeners[1]);
} catch (java.lang.SecurityException ex) {
Log.i(Application.TAG, "fail to request location update, ignore", ex);
} catch (IllegalArgumentException ex) {
Log.d(Application.TAG, "network provider does not exist, " + ex.getMessage());
}
try {
mLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 0, 0,
mLocationListeners[0]);
} catch (java.lang.SecurityException ex) {
Log.i(Application.TAG, "fail to request location update, ignore", ex);
} catch (IllegalArgumentException ex) {
Log.d(Application.TAG, "gps provider does not exist " + ex.getMessage());
}
}
}
出了什么问题？请帮忙..我应该在哪里调用removeUpdates？谢谢..
最佳答案
您注册了 2 个提供商的更新，您是否从这两个提供商处注销了注册？
此外，要使 boolean 标志起作用，您需要进行更改 - 在函数末尾将其设置为 true，并将 if 更改为 if(!receivedLocation) 这将使其生效只运行一次。事实上，它永远不会运行。
关于java - 删除位置管理器不起作用的更新，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/41678531/