如何在Firebase RecolyerView上设置Adapter？

Question

我有一个电影应用程序，其中一个名为“现在放映”的列表项将打开一个新的活动，以加载从我的firebase电影数据库中提取的电影列表。但是，当我按下“现在显示”时，app就会崩溃。这是我的密码

public class NowShowing extends AppCompatActivity {

    RecyclerView movieRecyclerView;
    FirebaseDatabase movieFirebaseDatabase;
    DatabaseReference moviesRef;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_now_showing);
            //recyclerview
        movieRecyclerView = findViewById(R.id.listnowshowingmovies);
        movieRecyclerView.setAdapter(adapter);
        movieRecyclerView.setLayoutManager(new GridLayoutManager(this, 1));
            //send query to Firebasedatabase
        movieFirebaseDatabase = FirebaseDatabase.getInstance();
        moviesRef = movieFirebaseDatabase.getReference("Data");
    }
    //load data into recyclerview onstart
    FirebaseRecyclerOptions <movies> options =
            new FirebaseRecyclerOptions.Builder<movies>().setQuery(moviesRef, movies.class).build();

    FirebaseRecyclerAdapter adapter = new FirebaseRecyclerAdapter<movies, ViewHolder>( options ) {
        @NonNull
        @Override
        public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

            View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.movies_cardview_all,parent,false);

            return new ViewHolder(view);
        }

        @Override
        protected void onBindViewHolder(@NonNull ViewHolder holder, int position, @NonNull movies model) {

            holder.setDetails(getApplicationContext(), model.getMovieTitle(),model.getMovieThumbnail(),model.getMovieSynopsis(),model.getMovieReleaseDate(),model.getMovieGenre(),
                    model.getMovieCast(),model.getMovieAgeRestriction(),model.getMovieRating());
        }
    };
}

这就是我得到的错误

Answer 1

movieRecyclerView.setAdapter(adapter);

调用时适配器为空。它需要用FirebaseRecyclerAdapter提供的信息进行实例化，但从提供的代码来看，适配器似乎是在尝试调用之后创建的。