Android：Osmdroid在觸摸上添加標記不准確

Question

我試圖根據此問題在mapview觸摸時添加標記，這是我的代碼

    GeoPoint geoPoint = new GeoPoint(mLatitude, mLongitude);
    IMapController mapController = mMapView.getController();
    mapController.setZoom(5);
    mapController.setCenter(geoPoint);

    Overlay overlay = new Overlay(getActivity()) {

        ItemizedIconOverlay<OverlayItem> items = null;

        @Override
        protected void draw(Canvas c, MapView osmv, boolean shadow) {

        }

        @Override
        public boolean onSingleTapConfirmed(MotionEvent e, MapView mapView) {
            Projection proj = mapView.getProjection();
            GeoPoint loc = (GeoPoint) proj.fromPixels((int)e.getX(), (int)e.getY());
            double longitude = loc.getLongitudeE6()/1000000;
            double latitude = loc.getLatitudeE6()/1000000;

            mLatitude = latitude;
            mLongitude = longitude;

            ArrayList<OverlayItem> markers = new ArrayList<>();
            OverlayItem item = new OverlayItem("", "", new GeoPoint(latitude, longitude));
            item.setMarker(ContextCompat.getDrawable(getActivity(), R.drawable.ic_maps_marker_large));
            markers.add(item);

            if (items == null) {
                items = new ItemizedIconOverlay<>(getActivity(), markers, null);
                mMapView.getOverlays().add(items);
                mMapView.invalidate();
            } else {
                mMapView.getOverlays().remove(items);
                mMapView.invalidate();
                items = new ItemizedIconOverlay<>(getActivity(), markers, null);
                mMapView.getOverlays().add(items);
            }
            return true;
        }

    };

    mMapView.getOverlays().add(overlay);

問題是放大標記添加到隨機位置時不准確。 但是，如果mapview縮小（大約在5縮放級別及以下），效果很好。

Answer 1

（代表OP發布）。

最后，我可以使用以下代碼解決此問題：

    GeoPoint geoPoint = new GeoPoint(mLatitude, mLongitude);
    IMapController mapController = mMapView.getController();
    mapController.setZoom(5);
    mapController.setCenter(geoPoint);

    Overlay overlay = new Overlay(getActivity()) {

        ItemizedIconOverlay<OverlayItem> items = null;

        @Override
        protected void draw(Canvas c, MapView osmv, boolean shadow) {

        }

        @Override
        public boolean onSingleTapConfirmed(MotionEvent e, MapView mapView) {
            Projection proj = mapView.getProjection();
            GeoPoint loc = (GeoPoint) proj.fromPixels((int)e.getX(), (int)e.getY());
            double longitude = loc.getLongitude();
            double latitude = loc.getLatitude();
            mLatitude = latitude;
            mLongitude = longitude;

            ArrayList<OverlayItem> markers = new ArrayList<>();
            OverlayItem item = new OverlayItem("", "", new GeoPoint(latitude, longitude));
            item.setMarker(ContextCompat.getDrawable(getActivity(), R.drawable.ic_maps_marker_large));
            markers.add(item);

            if (items == null) {
                items = new ItemizedIconOverlay<>(getActivity(), markers, null);
                mMapView.getOverlays().add(items);
                mMapView.invalidate();
            } else {
                mMapView.getOverlays().remove(items);
                mMapView.invalidate();
                items = new ItemizedIconOverlay<>(getActivity(), markers, null);
                mMapView.getOverlays().add(items);
            }
            return true;
        }

    };

    mMapView.getOverlays().add(overlay);