從firebase獲取數據，在android中執行后屏幕顯示空白

Question

主要活動：

public class MainActivity extends AppCompatActivity {
   private RecyclerView mRecyclerView;
   private FirebaseAdapter mAdapter;
    private static final String TAG = "MainActivity";

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

        mRecyclerView = (RecyclerView)findViewById(R.id.recyclerview);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));

        FirebaseRecyclerOptions<DataClass> options =
                new FirebaseRecyclerOptions.Builder<DataClass>()
                        .setQuery(FirebaseDatabase.getInstance().getReference().child("Users"), DataClass.class)
                        .build();
        mAdapter = new FirebaseAdapter(options);
        mRecyclerView.setAdapter(mAdapter);
        mRecyclerView.addItemDecoration(new DividerItemDecoration(this,DividerItemDecoration.VERTICAL));
    }
    @Override
    protected void onStart() {
        super.onStart();
        mAdapter.startListening();
    }
    @Override
    protected void onStop() {
        super.onStop();
        mAdapter.stopListening();
    }
}

Firebase 適配器

public class FirebaseAdapter extends FirebaseRecyclerAdapter<DataClass,FirebaseAdapter.MyviewHolder> {
    private static final String TAG = "FirebaseAdapter";
    public FirebaseAdapter(@NonNull FirebaseRecyclerOptions<DataClass> options) {
        super(options);
    }

    @Override
    protected void onBindViewHolder(@NonNull MyviewHolder holder, int position, @NonNull DataClass model) {
      holder.name.setText(model.getName());
      holder.age.setText(model.getAge());
        Log.d(TAG, "onBindViewHolder: Now Bind method executing");
    }

    @NonNull
    @Override
    public MyviewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
        View v=  layoutInflater.inflate(R.layout.row_represent,parent,false);
        MyviewHolder v1 = new MyviewHolder(v);
        Log.d(TAG, "onCreateViewHolder: Now on create method executing");
        return v1;
    }
    
    public static class MyviewHolder extends RecyclerView.ViewHolder{
        TextView name;
        TextView age;
        public MyviewHolder(@NonNull View itemView) {
            super(itemView);
            name = (TextView)itemView.findViewById(R.id.names);
            age = (TextView) itemView.findViewById(R.id.age);
        }
    }
}

數據類

public class DataClass {

    private  String name;
       private String age;

       public DataClass(){

       }

    public DataClass(String name, String age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public String getAge() {
        return age;
    }
}



 doubt in this parts
     public DataClass(String name, String age) {
                this.name = name;
                this.age = age;
            }
          protected void onBindViewHolder(@NonNull MyviewHolder holder, int position, @NonNull DataClass model) {
              holder.name.setText(model.getName());
              holder.age.setText(model.getAge());
                Log.d(TAG, "onBindViewHolder: Now Bind method executing");
            }
because showing me that constructor never used 

我沒有收到任何錯誤，但我的屏幕仍然顯示為空，實際上它顯示的是空數據如何找到它，伙計們告訴我如何解決這個問題我知道我在這段代碼的某個地方犯了一個小錯誤，幫助我糾正它謝謝……………………………………………………………………………………………………………………………………………………………………

Answer 1

替換此代碼

從

mRecyclerView.setLayoutManager(new LinearLayoutManager(this));

到

RecyclerView.LayoutManager layoutManager;
layoutManager = new LinearLayoutManager(this, RecyclerView.VERTICAL, false);
mRecyclerView.setLayoutManager(layoutManager);

希望這項工作。

Answer 2

你在 firebase 數據庫中有任何消息還是空的？

你可以通過firebase添加一些消息，這樣你就可以檢查它