检查地图上的标记是否已删除-Android[重复]

Question

override fun onMapReady(googleMap: GoogleMap) {
    this.googleMap = googleMap

    val markerOptions = MarkerOptions()
    markerOptions.position(LatLng(31.520959,74.352154))
  markerOptions.icon(BitmapDescriptorFactory.fromResource(R.drawable.curr_loc_grey))
    val marker = googleMap.addMarker(markerOptions)
   /........../
    marker.remove()
}

api'com.google.maps:google-maps-services:0.10.2'

当我调试时，我看到标记。isvisible添加时为true，并且在remove()之后为true。是虫子吗？

Answer 1

无论如何，您可以在将标记添加到map的同时将其添加到HashSet中：

...
HashSet<Makrer> markersOnMap = new HashSet<>();
...

...
// when add marker to map
Marker marker = googleMap.addMarker(markerOptions);
markersOnMap.add(marker);
...

...
// when remove
markersOnMap.remove(marker);
marker.remove();
...

...
// when check is marker on map
if (markersOnMap.contains(marker)) {
    // marker is on map   
} else {
    // marker removed   
}

当然，这只是方法描述，而不是最终代码。

更新：

public class MarkesrMapView extends MapView implements OnMapReadyCallback {

    private OnMapReadyCallback mMapReadyCallback;
    private GoogleMap mGoogleMap;
    private HashSet<Makrer> mMarkersOnMap;

    public MarkersMapView(@NonNull Context context) {
        super(context);
        init();
    }

    public MarkersMapView(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public MarkersMapView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    public MarkersMapView(@NonNull Context context, @Nullable GoogleMapOptions options) {
        super(context, options);
        init();
    }

    private void init() {
        mMarkersOnMap = new HashSet<>();
    }

    @Override
    public void getMapAsync(OnMapReadyCallback callback) {
        mMapReadyCallback = callback;
        super.getMapAsync(this);
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mGoogleMap = googleMap;
        if (mMapReadyCallback != null) {
            mMapReadyCallback.onMapReady(googleMap);
        }
    }

    public Marker addMarker(MarkerOptions markerOptions) {
        Marker marker = mGoogleMap.addMarker(markerOptions);
        mMarkersOnMap.add(marker);
        return marker;
    }

    public void removeMarker(Marker marker) {
        if (marker == null) return;
        mMarkersOnMap.remove(marker);
        marker.remove();
    }

    public boolean isOnMap(Marker marker) {
        if (marker == null) return false;
        return mMarkersOnMap.contains(marker);
    }
}

...
private markersMapView mMapView;
...

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

    Bundle mapViewBundle = null;
    if (savedInstanceState != null) {
        mapViewBundle = savedInstanceState.getBundle(MAP_VIEW_BUNDLE_KEY);
    }

    mMapView = (MarkersMapView) findViewById(R.id.mapview);
    mMapView.onCreate(mapViewBundle);
    mMapView.getMapAsync(new OnMapReadyCallback() {
        @Override
        public void onMapReady(GoogleMap googleMap) {
            mGoogleMap = googleMap;
            mMapView.addMarker(new MarkerOptions().position(...).title("Marker"));
        }
    });

   ...
   if (mMapView.isOnMap(myMarker)) {
      ...
   }