Question

对不起，但仍然是新手。我设法获得AsyncMap并在我的位置显示我的标记。现在，我查询Firebase数据库以检索数据以放置更多标记

    public void addMarkers() {
            if(noUpdateLocation.equals("not_allowed")){
        Query latitudeToAdd = markersNotAllowedToAdd.orderByChild("location_lat").limitToFirst(10).endAt(online_user_id);
        latitudeToAdd.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
               Iterable<DataSnapshot> latitudeIterator = dataSnapshot.getChildren();
               Iterator<DataSnapshot> iterator = latitudeIterator.iterator();
               while(iterator.hasNext()){
                   DataSnapshot foundLatitude = iterator.next();
                   latitudeList.add((Double) foundLatitude.child("location_lat").getValue());
                   Log.d(TAG,"addMarkers :" + latitudeList.toString());
               }

            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

        Query longitudeToAdd = markersNotAllowedToAdd.orderByChild("location_lng").limitToFirst(10).endAt(online_user_id);
        longitudeToAdd.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                Iterable<DataSnapshot> longitudeIterator = dataSnapshot.getChildren();
                Iterator<DataSnapshot> iterator = longitudeIterator.iterator();
                while(iterator.hasNext()){
                    DataSnapshot foundLongitude = iterator.next();
                    longitudeList.add((Double) foundLongitude.child("location_lat").getValue());
                    Log.d(TAG,"addMarkers : " + longitudeList.toString());
                }
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

当我尝试运行它并获得有关结果的日志时，我得到了消息

    W/art: Before Android 4.1, method int android.support.v7.widget.DropDownListView.lookForSelectablePosition(int, boolean) would have incorrectly overridden the package-private method in android.widget.ListView

我在addMarkers方法内部编写的代码的最后一部分是

     mMap.setOnMapLoadedCallback(new GoogleMap.OnMapLoadedCallback() {
            @Override
            public void onMapLoaded() {
                for(int i=0; i<latitudeList.size();i++){
                    LatLng markersLatLng = new LatLng(latitudeList.get(i),longitudeList.get(i));
                    mMap.addMarker(new MarkerOptions()
                    .position(markersLatLng));
                    Log.d(TAG,"add Markers :" + markersLatLng.toString());
                }
            }
        });

未添加或显示任何标记。我在哪里错了？

Googlemaps添加标记时出现问题

0 个答案: