Question

我不知道如何通过GPS服务跟踪用户的位置。

Answer 1

1。。您必须使用Google Maps Activity创建项目：

2。。您必须在注释中的链接之后创建Google API密钥，并将其插入此处：

3。。确保在您的Manifest.xml中添加这些权限：

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET"/>

4。。这是“地图活动”代码示例，用于获取用户的当前位置：

公共类MapsActivity扩展FragmentActivity实现OnMapReadyCallback {

private GoogleMap mMap;
LocationManager locationManager;
private static final int REQUEST_LOCATION_PERMISSION = 1;
Marker marker;
LocationListener locationListener;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps);
    // Obtain the SupportMapFragment and get notified when the map is ready to be used.
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);
    locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
    if (ActivityCompat.checkSelfPermission(this,
            Manifest.permission.ACCESS_FINE_LOCATION)
            != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this, new String[]
                        {Manifest.permission.ACCESS_FINE_LOCATION},
                REQUEST_LOCATION_PERMISSION);
    }
    locationListener = new LocationListener() {
        @Override
        public void onLocationChanged(Location location) {
            double latitude = location.getLatitude();
            double longitude = location.getLongitude();
            //get the location name from latitude and longitude
            Geocoder geocoder = new Geocoder(getApplicationContext());
            try {
                List<Address> addresses =
                        geocoder.getFromLocation(latitude, longitude, 1);
                String result = addresses.get(0).getLocality() + ":";
                result += addresses.get(0).getCountryName();
                LatLng latLng = new LatLng(latitude, longitude);
                if (marker != null) {
                    marker.remove();
                    marker = mMap.addMarker(new MarkerOptions().position(latLng).title(result));
                    mMap.setMaxZoomPreference(20);
                    mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, 12.0f));
                } else {
                    marker = mMap.addMarker(new MarkerOptions().position(latLng).title(result));
                    mMap.setMaxZoomPreference(20);
                    mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, 21.0f));
                }


            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {

        }

        @Override
        public void onProviderEnabled(String provider) {

        }

        @Override
        public void onProviderDisabled(String provider) {

        }
    };
    locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
}


/**
 * Manipulates the map once available.
 * This callback is triggered when the map is ready to be used.
 * This is where we can add markers or lines, add listeners or move the camera. In this case,
 * we just add a marker near Sydney, Australia.
 * If Google Play services is not installed on the device, the user will be prompted to install
 * it inside the SupportMapFragment. This method will only be triggered once the user has
 * installed Google Play services and returned to the app.
 */
@Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;
}

@Override
protected void onStop() {
    super.onStop();
    locationManager.removeUpdates(locationListener);
}}

我如何使用gps提供跟随用户位置的服务？

1 个答案: