更新地图标记位置 onLocationChanged() 不起作用

Question

我正在制作 google 地图，我想在 onLocationChanged() 方法中用户位置发生变化时更改地图标记位置。我在 Stack overflow 上尝试了很多可用的解决方案，但 none 适合我。我试过和许多其他人但都失败了。

我没有找到更新标记的正确代码方法。

非常感谢！

here's my MapsActivity

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, TaskLoadedCallback {

    static Marker now;
    public static GoogleMap mMap;
    private Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_track_order);
        Log.i("map", "create");

        SupportMapFragment mapFragment1 = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
        if (mapFragment1 != null) {
            mapFragment1.getMapAsync(this);
        }

        initViews();
        setToolbar()
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {

 mMap = googleMap;
        if (!runtime_permissions()) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                Intent serviceIntent = new Intent(getApplicationContext(), MyService.class);
                ContextCompat.startForegroundService(getApplicationContext(), serviceIntent);
            } else {
                startService(new Intent(getApplicationContext(), MyService.class));
            }
        }


        mMap.addMarker(place1);
        mMap.addMarker(place2);

        CameraPosition googlePlex = CameraPosition.builder()
                .target(new LatLng(31.527653,74.455632))
                .zoom(7)
                .bearing(0)
                .tilt(45)
                .build();

        mMap.animateCamera(CameraUpdateFactory.newCameraPosition(googlePlex), 5000, null);

}

here's my Service class

public class MyService  extends Service {


    public static LocationListener listener;
    public static LocationManager locationManager;
    private String locationAddress;

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

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
            startMyOwnForeground();
        else
            startForeground(1, new Notification());
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {

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

                double latitude = location.getLatitude();
                double longitude = location.getLongitude();
                String userAddress = address(latitude, longitude);

                 /*not working*/
                Marker myMarker = null;
                if(myMarker == null){
                  //  marker = mMap.addMarker(options);
                }
                else {
                    marker.setPosition(new LatLng(location.getLatitude(),location.getLongitude()));
                }

            }

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

            }

            @Override
            public void onProviderEnabled(String s) {

            }

            @Override
            public void onProviderDisabled(String s) {
                Intent i = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                startActivity(i);
            }

        };

        locationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);

        //noinspection MissingPermission
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        }
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, CommonObjects.DELAY_LOCATION_UPDATE, 0, listener);

        return START_STICKY;
    }
}

Answer 1

请在locationChangedMethod中添加

 MarkerOptions pin_01_markerOptions = new MarkerOptions();
                    pin_01_markerOptions.position(currentLatLng);
                    pin_01_markerOptions.icon(BitmapDescriptorFactory.fromBitmap(pin_01_marker));

                mMap.addMarker(pin_01_markerOptions);




 LatLng currentLatLng = new LatLng(location.getLatitude(),location.getLongitude());

                CameraUpdate update = CameraUpdateFactory.newLatLngZoom(currentLatLng,
                        15);
                mMap.moveCamera(update);

Answer 2

经过深思熟虑，我发现无法在 onLocationChanged() 中更新地图标记。相反，我必须更新我的标记 onMapReady() 方法。

通过从我的 Service class 方法发送广播到 onMapReady() 方法，我得到了问题的解决方案 更新地图标记位置 onLocationChanged()

更新代码：

MyService.java

public class MyService  extends Service {

     ...   

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

      ...
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {

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

                double latitude = location.getLatitude();
                double longitude = location.getLongitude();
                String userAddress = address(latitude, longitude);

                 /*sending broadcast*/
                Intent i = new Intent("location_update");
                i.putExtra("latitude", latitude);
                i.putExtra("longitude", longitude);
                i.putExtra("address", userAddress);
                sendBroadcast(i);

            }

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

            }

            @Override
            public void onProviderEnabled(String s) {

            }

            @Override
            public void onProviderDisabled(String s) {
                ...
            }

        };

      ...
        return START_STICKY;
    }
}

MapsActivity.java

此外，我在 onCreate() 开始 Service 而不是 onMapReady()。

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, TaskLoadedCallback {

    ...

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_track_order);

       ...

       /* staring service from here*/
       if (!runtime_permissions()) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                Intent serviceIntent = new Intent(getApplicationContext(), MyService.class);
                ContextCompat.startForegroundService(getApplicationContext(), serviceIntent);
            } else {
                startService(new Intent(getApplicationContext(), MyService.class));
            }
        }
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {

        mMap = googleMap;
        place2 = new MarkerOptions().position(destination).title("Isl");
        mMap.addMarker(place2);

        /*receiving broadcast*/
        if (broadcastReceiver == null) {
            broadcastReceiver = new BroadcastReceiver() {
                @Override
                public void onReceive(Context context, Intent intent) {

                    lat = (double) intent.getExtras().get("latitude");
                    lng = (double) intent.getExtras().get("longitude");
                    String  userAddress = (String) intent.getExtras().get("address");

                    place1 = new MarkerOptions().position(new LatLng(lat, lng)).title("Lahore");
                    mMap.addMarker(place1);
                }
            };
        }
        registerReceiver(broadcastReceiver, new IntentFilter("location_update"));


        CameraPosition googlePlex = CameraPosition.builder()
                .target(new LatLng(31.527653,74.455632))
                .zoom(7)
                .bearing(0)
                .tilt(45)
                .build();

        mMap.animateCamera(CameraUpdateFactory.newCameraPosition(googlePlex), 5000, null);
      }
}

更新地图标记位置 onLocationChanged() 不起作用

update map marker position onLocationChanged() is not working

android

google-maps

google-maps-markers