具有房间数据库的Android分页；RecyclerView：未连接适配器；跳过布局

我正在使用Android寻呼和房间数据库。我将使用改装来获取数据。但我得到的错误是没有连接适配器；跳过布局。我搜索了很多，但没有找到解决方案。基本url正在工作，出于安全原因，我只是隐藏基本url

  private StoreAdapter storeAdapter;
    private Store_ViewModel store_viewModel;
    private RecyclerView recyclerView;


    private static final String URL_DATA="https://xxxx/";
    //insertion
    private Store_Repository store_repository;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        store_repository=new Store_Repository(getApplication());

        //adapter
        storeAdapter=new StoreAdapter(getApplicationContext(), this);


        //recycler
        recyclerView=findViewById(R.id.recycler_store);
        RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getApplicationContext());
        recyclerView.setLayoutManager(layoutManager);
        recyclerView.setHasFixedSize(true);


        store_viewModel=new ViewModelProvider(this).get(Store_ViewModel.class);


        store_viewModel.pagedListLiveData.observe(this, new Observer<PagedList<StoreModel>>() {
            @Override
            public void onChanged(PagedList<StoreModel> storeModels) {
                storeAdapter.submitList(storeModels);
                recyclerView.setAdapter(storeAdapter);
            }
        });

        getAllProducts();


    }

    private void getAllProducts() {
        Retrofit retrofit=new Retrofit.Builder()
                .baseUrl(URL_DATA)
                .addConverterFactory(GsonConverterFactory.create())
                .build();
        
//calling api
        Api api=retrofit.create(Api.class);
        Call<List<StoreModel>>call=api.getAllProducts();
        call.enqueue(new Callback<List<StoreModel>>() {
            @Override
            public void onResponse(Call<List<StoreModel>> call, Response<List<StoreModel>> response) {
                    if (response.isSuccessful())
                    {
                        store_repository.insert(response.body());
                    }
            }

            @Override
            public void onFailure(Call<List<StoreModel>> call, Throwable t) {
                Toast.makeText(MainActivity.this, "Something get Wrong", Toast.LENGTH_SHORT).show();
            }
        });

    }

ApiInterface

 public interface Api {
    @GET("/get-products")
    Call<List<StoreModel>>getAllProducts();
}

下面是Dao类

    @Dao
public interface StoreDao {
    
    @Insert(onConflict = OnConflictStrategy.REPLACE)
    void insert(List<StoreModel> storeModels);

    @Query("DELETE FROM store")
    void deleteAll();

    @Query("SELECT * FROM store ORDER BY database_id ASC")
    DataSource.Factory<Integer,StoreModel>getAllItems();

}

@Dao
公共接口StoreDao{
@插入（onConflict=OnConflictStrategy.REPLACE）
无效插入（列出存储模型）；
@查询（“从存储中删除”）
void deleteAll（）；
@查询（“按数据库_id ASC从门店订单中选择*）
DataSource.FactorygetAllItems（）；
}

Set

recyclerView.setAdapter（storeAdapter）在观察者之外，因为每次观察数据时，它都会设置适配器。因此，
adapter
仅连接到
recyclerView
一次。像

recyclerView.setAdapter(storeAdapter);
store_viewModel.pagedListLiveData.observe(this, new Observer<PagedList<StoreModel>>() {
        @Override
        public void onChanged(PagedList<StoreModel> storeModels) {
            storeAdapter.submitList(storeModels);
            //recyclerView.setAdapter(storeAdapter); 
        }
    });

然后，您的
界面应如您所期望的那样如下所示
ResponseObject
此处

    public interface Api {
    @GET("/get-products")
    Call<ResponseObject> getAllProducts();
}

公共接口Api{
@获取（“/获取产品”）
调用getAllProducts（）；
}
通过在observeronCreateViewHolder（）外部设置recyclerView调用失败时，返回null，为什么要这样做？我忘了提到-返回新的StoreViewHolder（LayoutFlater.from（parent.getContext（））。充气（R.layout.store\u card，parent，false））；但是仍然没有得到数据你从API得到的响应数据正确吗？@是的-我也在邮递员那里查过了
   @Entity(tableName = "store",indices = @Index(value="product_id",unique = true))
public class StoreModel {

    @PrimaryKey(autoGenerate = true)
    private int database_id;

    @SerializedName("product_id")
    private int product_id;

    @SerializedName("product_brand_id")
    private int product_brand_id;

    @SerializedName("product_name")
    private String product_name;

    @SerializedName("product_code")
    private int product_code;

    @SerializedName("mrp")
    private int mrp;

    @SerializedName("price")
    private int price;

    @SerializedName("product_weight")
    private int product_weight;

    @SerializedName("product_weight_unit")
    private String product_weight_unit;

    public StoreModel() {
    }

    public StoreModel(int product_id, int product_brand_id, String product_name, int product_code, int mrp, int price, int product_weight, String product_weight_unit) {
        this.product_id = product_id;
        this.product_brand_id = product_brand_id;
        this.product_name = product_name;
        this.product_code = product_code;
        this.mrp = mrp;
        this.price = price;
        this.product_weight = product_weight;
        this.product_weight_unit = product_weight_unit;
    }

    public int getProduct_id() {
        return product_id;
    }

    public void setProduct_id(int product_id) {
        this.product_id = product_id;
    }

    public int getProduct_brand_id() {
        return product_brand_id;
    }

    public void setProduct_brand_id(int product_brand_id) {
        this.product_brand_id = product_brand_id;
    }

    public String getProduct_name() {
        return product_name;
    }

    public void setProduct_name(String product_name) {
        this.product_name = product_name;
    }

    public int getProduct_code() {
        return product_code;
    }

    public void setProduct_code(int product_code) {
        this.product_code = product_code;
    }

    public int getMrp() {
        return mrp;
    }

    public void setMrp(int mrp) {
        this.mrp = mrp;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public int getProduct_weight() {
        return product_weight;
    }

    public void setProduct_weight(int product_weight) {
        this.product_weight = product_weight;
    }

    public String getProduct_weight_unit() {
        return product_weight_unit;
    }

    public void setProduct_weight_unit(String product_weight_unit) {
        this.product_weight_unit = product_weight_unit;
    }

    public int getDatabase_id() {
        return database_id;
    }

    public void setDatabase_id(int database_id) {
        this.database_id = database_id;
    }



}

    @Dao
public interface StoreDao {
    
    @Insert(onConflict = OnConflictStrategy.REPLACE)
    void insert(List<StoreModel> storeModels);

    @Query("DELETE FROM store")
    void deleteAll();

    @Query("SELECT * FROM store ORDER BY database_id ASC")
    DataSource.Factory<Integer,StoreModel>getAllItems();

}

recyclerView.setAdapter(storeAdapter);
store_viewModel.pagedListLiveData.observe(this, new Observer<PagedList<StoreModel>>() {
        @Override
        public void onChanged(PagedList<StoreModel> storeModels) {
            storeAdapter.submitList(storeModels);
            //recyclerView.setAdapter(storeAdapter); 
        }
    });

    public class ResponseObject{
    //@SerializedName("status")
    //private int status;


    @SerializedName("data")
    private List<StoreModel> storeModelList;

    //getters and setters goes here
}

    public interface Api {
    @GET("/get-products")
    Call<ResponseObject> getAllProducts();
}