java - Firebase 数据库从子 android 访问节点

Question

我有一个这样的节点

在本例中我搜索 id 节点 01, 02,...当我找到它时，我将其发送到另一个 Activity ，在该 Activity 中我搜索匹配的 ID 号，如下所示

当 Id 匹配时，我将它们显示在回收器 View 中，现在我想获取我在本例中搜索的节点的父节点 Restaurant--> 01但每当我调用我的database.getKey时，它都会返回Restaurant而不是01

我的问题是如何获取父节点而不是原始节点或(父节点的父节点)？非常感谢

这是我的代码:

RecyclerView recyclerView;
RecyclerView.LayoutManager layoutManager;


FirebaseDatabase database;
DatabaseReference restaurantList;

String restaurantId;
FirebaseRecyclerAdapter<RestaurantModel, RestaurantViewHolder> adapter;

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


    //Firebase
    database = FirebaseDatabase.getInstance();
    restaurantList = database.getReference("Restaurant");

    recyclerView = (RecyclerView) findViewById(R.id.recycler_restaurants);
    layoutManager =  new LinearLayoutManager(this);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(layoutManager);

    if(getIntent() !=null)
        restaurantId = getIntent().getStringExtra("RestaurantId");
    if(!restaurantId.isEmpty() && restaurantId != null)
    {
        loadListRestaurant(restaurantId);

    }

}




private void loadListRestaurant(final String restaurantId) {
    adapter = new FirebaseRecyclerAdapter<RestaurantModel, RestaurantViewHolder>(
            RestaurantModel.class,
            R.layout.restaurant_menu_item,
            RestaurantViewHolder.class,
            restaurantList.orderByChild("RestaurantId").equalTo(restaurantId)
    ) {
        @Override
        protected void populateViewHolder(RestaurantViewHolder viewHolder, RestaurantModel model, int position) {
            viewHolder.restaurantName.setText(model.getName());
            Picasso.get().load(model.getImage())
                    .into(viewHolder.restaurantImage);
            viewHolder.restaurantRate.setRating(Float.parseFloat(model.getRating()));
            viewHolder.restaurantCategory.setText(model.getDescription());
            try {
                if (Integer.parseInt(model.getPrice()) == 0)
                    viewHolder.priceRate.setRating(2);
                else
                    viewHolder.priceRate.setRating(Integer.parseInt(model.getPrice()));
            }
            catch (Exception e){}




            final RestaurantModel local = model;
            viewHolder.setItemClickListener(new ItemClickListener() {
                @Override
                public void onClick(View view, int position, boolean isLongClick) {
                    Intent fragmentintent = new Intent(RestaurantList.this, main_intermediate.class);
                    fragmentintent.putExtra("RestaurantId", restaurantList.getKey());
                    Log.d(TAG, restaurantList.getKey() );
                    startActivity(fragmentintent);
                }
            });
        }
    };
    recyclerView.setAdapter(adapter);

}

}

Answer 1

要获取 key ，您需要在 01 - 02 内部循环，以便在使用 getKey() 时能够检索它们，因此请尝试以下操作:

DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Restaurant");

reference.addListenerForSingleValueEvent(new ValueEventListener() {
 @Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot datas: dataSnapshot.getChildren()){
   String keys=datas.getKey();
    }
 }
@Override
public void onCancelled(DatabaseError databaseError) {
    }
 });