问如何利用firebase数据库开发回收视图中的新活动

EN

RecyclerView recyclerView;
MainAdapter mainAdapter;


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

    recyclerView = (RecyclerView)findViewById(R.id.recView);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));

    FirebaseRecyclerOptions<MainModel> options =
            new FirebaseRecyclerOptions.Builder<MainModel>()
                    .setQuery(FirebaseDatabase.getInstance().getReference().child("category"), MainModel.class)
                    .build();

    mainAdapter = new MainAdapter(options);
    recyclerView.setAdapter(mainAdapter);
}

@Override
protected void onStart() {
    super.onStart();
    mainAdapter.startListening();
}

@Override
protected void onStop() {
    super.onStop();
    mainAdapter.stopListening();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

    getMenuInflater().inflate(R.menu.search,menu);
    MenuItem item = menu.findItem(R.id.search);
    SearchView searchView = (SearchView)item.getActionView();

    searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
        @Override
        public boolean onQueryTextSubmit(String query) {
            txtSearch(query);
            return false;
        }

        @Override
        public boolean onQueryTextChange(String query) {
            txtSearch(query);
            return false;
        }
    });

    return super.onCreateOptionsMenu(menu);
}

private void txtSearch(String str)
{
    FirebaseRecyclerOptions<MainModel> options =
            new FirebaseRecyclerOptions.Builder<MainModel>()
                    .setQuery(FirebaseDatabase.getInstance().getReference().child("category").orderByChild("name").startAt(str).endAt(str+"~"), MainModel.class)
                    .build();

    mainAdapter = new MainAdapter(options);
    mainAdapter.startListening();
    recyclerView.setAdapter(mainAdapter);
}

/**
 * Initialize a {@link RecyclerView.Adapter} that listens to a Firebase query. See
 * {@link FirebaseRecyclerOptions} for configuration options.
 *
 * @param options
 */
public MainAdapter(@NonNull FirebaseRecyclerOptions<MainModel> options) {
    super(options);
}

@Override
protected void onBindViewHolder(@NonNull MainAdapter.myViewHolder holder, int position, @NonNull MainModel model) {

    holder.categoryName.setText(model.getName());
    holder.categoryDesc.setText(model.getDescription());

    Glide.with(holder.categoryImage.getContext())
            .load(model.getImage())
            .placeholder(R.drawable.common_google_signin_btn_icon_dark)
            .error(R.drawable.common_google_signin_btn_icon_dark_normal)
            .into(holder.categoryImage);
}

@NonNull

@Override
public myViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.main_item,parent,false);
    return new myViewHolder(view);
}

class myViewHolder extends RecyclerView.ViewHolder{

    ImageView categoryImage;
    TextView categoryName, categoryDesc;


    public myViewHolder(@NonNull View itemView) {
        super(itemView);

        categoryImage = (ImageView)itemView.findViewById(R.id.categoryImage);
        categoryName = (TextView)itemView.findViewById(R.id.categoryName);
        categoryDesc = (TextView)itemView.findViewById(R.id.categoryDesc);

    }
}

String name,description,image;

MainModel()
{

}

public MainModel(String name, String description, String image) {
    this.name = name;
    this.description = description;
    this.image = image;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getDescription() {
    return description;
}

public void setDescription(String description) {
    this.description = description;
}

public String getImage() {
    return image;
}

public void setImage(String image) {
    this.image = image;
}