Android Google Maps onLocationChanged 未调用

Question

我知道有很多关于这个问题的线索，但没有什么能给我很好的答案。永远不会调用函数 onLocationChanged 接缝。

 @Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED &&
            ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        return;
    }
    mMap.setMyLocationEnabled(true);
    LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    Criteria criteria = new Criteria();
    String provider = locationManager.getBestProvider(criteria, true);

    LocationListener locationListener = new LocationListener() {
        @Override
        public void onLocationChanged(Location location) {
            Toast.makeText(getApplicationContext(), "New Location", Toast.LENGTH_SHORT).show();
            LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
            mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
            mMap.animateCamera(CameraUpdateFactory.zoomTo(20));
            mMap.addMarker(new MarkerOptions().position(latLng).title("Jesteś tutaj!"));
        }

        /* ... */
    };
    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 3000, 2, locationListener);
    locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 3000, 2, locationListener);
}

我做错了什么？

Answer 1

首先，您需要在真实设备而非虚拟设备中运行您的应用，并通过设置保持 GPS 开启。然后，您可以使用以下为我完成工作的方法。

    private void createMap()
    {
        TotalDistance.setText("Distance:");
        SupportMapFragment supportMapFragment=(SupportMapFragment)getChildFragmentManager().findFragmentById(R.id.map);
        //SupportMapFragment fm = (SupportMapFragment) getActivity().getSupportFragmentManager().findFragmentById(R.id.map);
        googleMap=supportMapFragment.getMap();

 /*       googleMap = ((SupportMapFragment) MainActivity.fragmentManager
                .findFragmentById(R.id.map)).getMap();*/
        locationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);
        // Creating a criteria object to retrieve provider
        Criteria criteria = new Criteria();

        // Getting the name of the best provider
        provider = locationManager.getBestProvider(criteria, true);

        // Getting Current Location
        if (ActivityCompat.checkSelfPermission(getActivity(), android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getContext(), android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }

        location = locationManager.getLastKnownLocation(LocationManager.PASSIVE_PROVIDER);

        googleMap.getUiSettings().setRotateGesturesEnabled(false);

        marker = new MarkerOptions().position(new LatLng(location.getLatitude(), location.getLongitude())).title(location.getLatitude() + " " + location.getLongitude());
        googleMap.addMarker(marker);
        CameraPosition cameraPosition = new CameraPosition.Builder().target(new LatLng(location.getLatitude(), location.getLongitude())).zoom(15).build();
        googleMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));

        googleMap.setMapType(GoogleMap.MAP_TYPE_TERRAIN);
        origin_latLng = new LatLng(location.getLatitude(), location.getLongitude());
    }

    private void intializeMap(Context context) {
        int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getActivity());

        // Showing status
        if (status != ConnectionResult.SUCCESS) { // Google Play Services are not available

            int requestCode = 10;
            Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, getActivity(), requestCode);
            dialog.show();

        } else { // Google Play Services are available

            // Getting reference to the SupportMapFragment of activity_main.xml

            if (ActivityCompat.checkSelfPermission(getActivity(), android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getActivity(), android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                // TODO: Consider calling
                //    ActivityCompat#requestPermissions
                // here to request the missing permissions, and then overriding
                //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                //                                          int[] grantResults)
                // to handle the case where the user grants the permission. See the documentation
                // for ActivityCompat#requestPermissions for more details.
                return;
            }
            googleMap.setMyLocationEnabled(true);
            googleMap.clear();

            if (location != null) {
                onLocationChanged(location);
            }

            locationManager.requestLocationUpdates(provider, 2000, 1, YOUR ACTIVITY REFERENCE);
            googleMap.stopAnimation();

        }
    }

    @Override
    public void onLocationChanged(Location location) {

        // Getting latitude of the current location
        double latitude = location.getLatitude();
        double longitude = location.getLongitude();
        finalLatlang=new LatLng(latitude,longitude);
        //  userlatLang.add(finalLatlang);

        CameraPosition cameraPosition = new CameraPosition.Builder().target(finalLatlang).zoom(15).build();
        googleMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
        Log.d("Latitude", " " + latitude);
        Log.d("Longitude", " " + longitude);

        // Showing the current location in Google Map
        googleMap.moveCamera(CameraUpdateFactory.newLatLng(finalLatlang));

        if(flag==1) {

            // Zoom in the Google Map
            googleMap.animateCamera(CameraUpdateFactory.zoomTo(15));
            flag++;
        }

    }

还请在您的 Activity 或 Fragment 中实现 LocationListener

Answer 2

 Criteria crit = new Criteria();
 crit.setAccuracy(Criteria.ACCURACY_FINE);
 String best = mgr.getBestProvider(crit, false);

以上是为了获得最好的位置提供者。

你可以在 onResume() 中给出你的 locationManager 请求；

 @Override public void onResume() {
super.onResume();
locationManager.requestLocationUpdates(, 10000, 1, locationListener);}

希望对你有所帮助。