在 Android Studio 中将标记移动到用户位置

Question

我正在尝试制作一个地图活动应用程序，该应用程序在运行时会使用标记在地图上显示用户的 GPS 位置。但是，在运行时，它只会在默认位置（悉尼）显示标记，请帮助。下面是我的代码..我尝试了很多方法，但它们仍然把我带到了悉尼。我想要做的是让应用程序在运行后直接将我带到我的位置。 以下是我的代码；

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_real_time_location);
    // 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);
    ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, PackageManager.PERMISSION_GRANTED);
    ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, PackageManager.PERMISSION_GRANTED);
}



public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;

    LatLng sydney = new LatLng(-34, 151);
    mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
    mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));

    locationListener = new LocationListener() {
        @Override
        public void onLocationChanged(Location location) {

            try {
                latLng = new LatLng(location.getLatitude(), location.getLongitude());

                mMap.addMarker(new MarkerOptions().position(latLng).title("My Current Position"));
                mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
            }
            catch (SecurityException e){
                e.printStackTrace();
            }
        }

        @Override
        public void onStatusChanged(String s, int i, Bundle bundle) {

        }

        @Override
        public void onProviderEnabled(String s) {

        }

        @Override
        public void onProviderDisabled(String s) {

        }
    };

    locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

    try {
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_UPDATE_TIME, MIN_UPDATES_DISTANCE, locationListener);
    }
    catch (SecurityException e){
        e.printStackTrace();
    }
}

Answer 1

使用 LocationCallback 来获取您的最新位置：

LocationCallback mLocationCallback = new LocationCallback() {
    @Override
    public void onLocationResult(LocationResult locationResult) {
        List<Location> locationList = locationResult.getLocations();
        if (locationList.size() > 0) {
            //The last location in the list is the newest
            Location location = locationList.get(locationList.size() - 1);
            Log.i(TAG, "Location " + location.getLatitude() + " " + location.getLongitude());

            mLastLocation = location;
            if (mCurrLocationMarker != null) {
                mCurrLocationMarker.remove();
            }

            //Create instance for current user lat and lng
            LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());

            // Add user position marker
            currentUserPositionMarker(latLng);

            //move map camera
            gMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, CURRENT_MAP_ZOOM));

        }
    }
};

/**
 * Add Marker for user current position
 *
 * @param latLng current lat and lng of user
 */
private void currentUserPositionMarker(LatLng latLng) {
    MarkerOptions markerOptions = new MarkerOptions();
    markerOptions.position(latLng);
    markerOptions.title(CURRENT_POSITION);
    mCurrLocationMarker = gMap.addMarker(markerOptions);

     //move map camera
     gMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, CURRENT_MAP_ZOOM));
}


@Override
public void onPause() {
    super.onPause();

    if (mFusedLocationProviderClient != null) {
        mFusedLocationProviderClient.removeLocationUpdates(mLocationCallback);
    }
}

@SuppressLint("MissingPermission")
@Override
public void onMapReady(GoogleMap googleMap) {
    gMap = googleMap;
    gMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
    gMap.getUiSettings().setMapToolbarEnabled(false);

    mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(SET_INTERVAL_FOR_ACTIVE_LOCATION_UPDATES); // 3 seconds interval
    mLocationRequest.setFastestInterval(SET_INTERVAL_FOR_ACTIVE_LOCATION_UPDATES);
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

    if (isFineLocationPermissionGranted())
        mFusedLocationProviderClient.requestLocationUpdates(mLocationRequest, mLocationCallback, Looper.myLooper());
}

Answer 2

您需要获取设备的最后一个已知位置，使用this 链接获取最后一个已知位置，然后将标记显示在您想要的位置。