Question

所以我的FireBase数据库中有多个位置： Database Structure

写下这个循环遍历所有这些节点，提取经度和纬度，然后将它们显示为标记。

    final DatabaseReference ref = FirebaseDatabase.getInstance().getReference("locations");
    final GeoFire geoFire = new GeoFire(ref);

    //Add a location
    //geoFire.setLocation("meetFar2", new GeoLocation(26.173027, -80.252871));

    final GeoQuery geoQuery = geoFire.queryAtLocation(new GeoLocation(userLocation.latitude, userLocation.longitude), 5.7);
    geoQuery.addGeoQueryEventListener(new GeoQueryEventListener() {
      @Override
      public void onKeyEntered(String key, GeoLocation location) {
        System.out.println(String.format("Key %s entered the search area at [%f,%f]", key, location.latitude, location.longitude));
        Query locationQuery = FirebaseDatabase.getInstance().getReference().child("locations");
        locationQuery.addValueEventListener(new ValueEventListener() {
          @Override
          public void onDataChange(DataSnapshot dataSnapshot) {
            for (DataSnapshot snap : dataSnapshot.getChildren()){
              Double latitude = (Double) snap.child("l/0").getValue();
              Double longitude = (Double) snap.child("l/1").getValue();
              LatLng meetLatLng = new LatLng(latitude, longitude);
              googleMap.addMarker(new MarkerOptions().position(meetLatLng));
            }
          }

          @Override
          public void onCancelled(DatabaseError databaseError) {

          }
        });
      }

      @Override
      public void onKeyExited(String key) {
        System.out.println(String.format("Key %s is no longer in the search area", key));
      }

      @Override
      public void onKeyMoved(String key, GeoLocation location) {
        System.out.println(String.format("Key %s moved within the search area to [%f,%f]", key, location.latitude, location.longitude));
      }

      @Override
      public void onGeoQueryReady() {
      }

      @Override
      public void onGeoQueryError(DatabaseError error) {
        Toast.makeText(MainActivity.this, "There was an error with this query " + error, Toast.LENGTH_SHORT).show();
      }
    });

在我获得用户的最后一个已知位置（设置为userLocation）之后，这一切都在onMapReady中完成。但是，当我运行程序时，如果查询的半径中至少有一个键，则地图会显示所有标记。如何仅将半径内的查询结果显示为标记？

Answer 1

意识到初始queryAtLocation查询从我的数据库返回正确数量的点，所以我删除了其中的第二个查询。代码现在看起来像这样：

final GeoQuery geoQuery = geoFire.queryAtLocation(new GeoLocation(userLocation.latitude, userLocation.longitude), 7.0);
    geoQuery.addGeoQueryEventListener(new GeoQueryEventListener() {
      @Override
      public void onKeyEntered(String key, GeoLocation location) {
        System.out.println(String.format("Key %s entered the search area at [%f,%f]", key, location.latitude, location.longitude));

        LatLng meetLatLng = new LatLng(location.latitude, location.longitude);
        googleMap.addMarker(new MarkerOptions().position(meetLatLng));
      }

显示所有标记的GeoFire查询

1 个答案: