Firebase，如何在键上更新数据

Question

我在更新存储桶（键）上的对象时遇到了一些困难。在持久性时，我将对象列表（在本例中为 Trip）push()到节点。后来，我检索了它，并在点击按钮时进行了更新（在本例中为更新出价信息）。我似乎找不到一种简单的方法来做到这一点，除非我之前推送行程时，我必须手动调用getkey()然后将自动生成的 uid 更新为对象 Trip 本身。有什么想法可以轻松完成吗？谢谢

mFirebaseAdapter = new FirebaseRecyclerAdapter<Trip,
            TripViewHolder>(
            Trip.class,
            R.layout.item_message,
            TripViewHolder.class,
            mFirebaseDatabaseReference.child(CHILD_TRIPS)) {
        @Override
        protected void populateViewHolder(TripViewHolder viewHolder, final Trip model, int position) {
            viewHolder.btnTakeNow.setOnClickListener(new View.OnClickListener() {
                 @Override
                 public void onClick(View v) {
                     Bid bidAtReserved = new Bid(mDriverCarInfo, model, MY_PRICE);
                     mFirebaseDatabaseReference.child(CHILD_TRIPS)
                             //here, I want to update the bidding to this trip, but 
                             //I can't get the uid of the trip, unless I had 
                             //manually recorded at the time of pushing the trip
                             .child(model.getUid()) 
                              .child("bids").push().setValue(bidAtReserved);

                 }
            });
        }
    };

Answer 1

我不太确定您要完成什么（相关 JSON 的片段 - 作为文本，而不是屏幕截图 - 会有所帮助）。但我最好的猜测是你正在寻找getRef().

protected void populateViewHolder(TripViewHolder viewHolder, final Trip model, final int position) {
    viewHolder.btnTakeNow.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            mFirebaseAdapter.getRef(position).child("price").setValue(MY_PRICE);
        }
    });
}

Answer 2

FirebaseRecylerAdapter 有一个名为 parseSnapShot 的覆盖，你可以像这样挂上它。我不知道更好的解决方案 - 所以希望有人能提供更好的解决方案。

mFirebaseAdapter = new FirebaseRecyclerAdapter<Trip,
                TripViewHolder>(
                Trip.class,
                R.layout.item_message,
                TripViewHolder.class,
                mFirebaseDatabaseReference.child(CHILD_TRIPS)) {
        @Override
        protected Trip parseSnapshot(DataSnapshot snapshot) {
            Trip trip = super.parseSnapshot(snapshot);
            trip.setDbKey(snapshot.getKey());
            return trip;
        }
        @Override
        protected void populateViewHolder(TripViewHolder viewHolder, final Trip model, int position) {
            viewHolder.btnTakeNow.setOnClickListener(new View.OnClickListener() {
                 @Override
                 public void onClick(View v) {
                     Bid bidAtReserved = new Bid(mDriverCarInfo, model, MY_PRICE);
                     mFirebaseDatabaseReference.child(CHILD_TRIPS)
                             //here, I want to update the bidding to this trip, but I can't get the uid of the trip, unless I had manually recorded at the time of pushing the trip
                             .child(model.getUid()) 
                              .child("bids").push().setValue(bidAtReserved);

                 }
            });
        }
    };