android - 使用回收视图从 Firebase 检索实时数据

Question

我想检索在回收视图中具有 request_type “received” 的唯一孩子，但我有一个问题打击代码检索当前用户的所有孩子，它们都具有 request_type “sent” 和 “received”

这是我的代码

public class RequestFragment extends Fragment {
    private  View requestview;
    private RecyclerView requestlist;
    private DatabaseReference requestref,userref;
    private FirebaseAuth mAuth;
    private String currentuserID;


    public RequestFragment() {

    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        requestview = inflater.inflate(R.layout.fragment_request, container, false);

        requestlist = requestview.findViewById(R.id.requestlist);
        requestlist.setLayoutManager(new LinearLayoutManager(getContext()));

        mAuth = FirebaseAuth.getInstance();
        currentuserID = mAuth.getCurrentUser().getUid();
        requestref = FirebaseDatabase.getInstance().getReference().child("chat request");

        userref = FirebaseDatabase.getInstance().getReference().child("users");


        return requestview;
    }

    @Override
    public void onStart() {
        super.onStart();

        FirebaseRecyclerOptions options =
                new FirebaseRecyclerOptions.Builder<contact>()
                        .setQuery(requestref.child(currentuserID),contact.class)
                        .build();

        FirebaseRecyclerAdapter<contact,RequestViewHolder> adapter =
                new FirebaseRecyclerAdapter<contact, RequestViewHolder>(options) {
                    @Override
                    protected void onBindViewHolder(@NonNull final RequestViewHolder holder, int position, @NonNull contact model)
                    {
                        holder.itemView.findViewById(R.id.request_accept_btn).setVisibility(View.VISIBLE);
                        holder.itemView.findViewById(R.id.request_cancle_btn).setVisibility(View.VISIBLE);

                        final  String list_user_id = getRef(position).getKey();

                        DatabaseReference getTypeRef = getRef(position).child("request_type").getRef();

                        getTypeRef.addValueEventListener(new ValueEventListener() {
                            @Override
                            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                                if (dataSnapshot.exists()){

                                    String type = dataSnapshot.getValue().toString();

                                    if (type.equals("received"))
                                    {
                                        userref.child(list_user_id).addValueEventListener(new ValueEventListener() {
                                            @Override
                                            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                                                if (dataSnapshot.hasChild("image")){

                                                    String profile = dataSnapshot.child("image").getValue().toString();
                                                    String userstatus = dataSnapshot.child("status").getValue().toString();
                                                    String username = dataSnapshot.child("name").getValue().toString();

                                                    holder.username.setText(username);
                                                    holder.userstatus.setText(userstatus);
                                                    Picasso.get().load(profile).placeholder(R.drawable.defaultprofile).into(holder.userimage);

                                                }
                                                else {

                                                    String userstatus = dataSnapshot.child("status").getValue().toString();
                                                    String username = dataSnapshot.child("name").getValue().toString();

                                                    holder.username.setText(username);
                                                    holder.userstatus.setText(userstatus);


                                                }

                                            }

                                            @Override
                                            public void onCancelled(@NonNull DatabaseError databaseError) {

                                            }
                                        });


                                    }



                                }

                            }

                            @Override
                            public void onCancelled(@NonNull DatabaseError databaseError) {

                            }
                        });

                    }

                    @NonNull
                    @Override
                    public RequestViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int viewType) {
                        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.user_display_layout,viewGroup,false);
                        RequestViewHolder requestViewHolder = new RequestViewHolder(view);
                        return requestViewHolder;
                    }
                };
        requestlist.setAdapter(adapter);
        adapter.startListening();




    }


    public  static class RequestViewHolder extends RecyclerView.ViewHolder
    {
        TextView username,userstatus;
        CircleImageView userimage;
        Button accept,cancle;

        public RequestViewHolder(@NonNull View itemView)
        {
            super(itemView);
            username = itemView.findViewById(R.id.user_profile_name);
            userstatus = itemView.findViewById(R.id.user_status);
            userimage = itemView.findViewById(R.id.user_profile_image);
            accept = itemView.findViewById(R.id.request_accept_btn);
            cancle = itemView.findViewById(R.id.request_cancle_btn);



        }
    }


} 

这段代码给了我当前用户的所有三个孩子，但我只想要在回收视图中请求类型为“received”的孩子

标签： androidfirebase-realtime-database

Answer 1

您可以在早期设置查询，即FirebaseRecyclerOptions. 像这样的东西。

//Creating query for specific condition
Query queryRequestType = requestref.orderByChild("request_type").equalTo("received");

FirebaseRecyclerOptions options = new FirebaseRecyclerOptions.Builder<contact>()
    .setQuery(queryRequestType, contact.class)
    .build();