Android Jetpack分页不显示超过2页的数据

Question

我正在使用android jetpack的分页库。我能够获取数据直到第2页，但我无法获取更多页面的数据，即使我在数据源中的loadAfter（）方法的api调用中传递params.key。我很简单，无法理解问题所在。

继承我的DataSource：

public class ApprovedBillsDataSource extends PageKeyedDataSource<Integer, BillsModel.Bills> {

    static int FIRST_PAGE = 1;

    String sortOrder;
    String searchParam;

    EmptyHandler emptyHandler;

    ApprovedBillsDataSource(String sortOrder, String searchParam, EmptyHandler emptyHandler) {

        this.sortOrder = sortOrder;
        this.searchParam = searchParam;
        this.emptyHandler = emptyHandler;
    }

    @Override
    public void loadInitial(@NonNull LoadInitialParams<Integer> params, @NonNull final LoadInitialCallback<Integer, BillsModel.Bills> callback) {

        RestClient.webServices().getCompletePartnerBills(FIRST_PAGE, 1, sortOrder, searchParam).enqueue(new Callback<ApiResponse<BillsModel>>() {
            @Override
            public void onResponse(Call<ApiResponse<BillsModel>> call, Response<ApiResponse<BillsModel>> response) {

                if (response.code() == 200) {

                    callback.onResult(response.body().getData().getBills(), null, FIRST_PAGE + 1);

                    if (response.body().getData().getBills() == null || response.body().getData().getBills().size() == 0) {

                        emptyHandler.onListEmpty();
                    }
                }
            }

            @Override
            public void onFailure(Call<ApiResponse<BillsModel>> call, Throwable t) {

            }
        });

    }

    @Override
    public void loadBefore(@NonNull LoadParams<Integer> params, @NonNull LoadCallback<Integer, BillsModel.Bills> callback) {


    }

    @Override
    public void loadAfter(@NonNull LoadParams<Integer> params, @NonNull final LoadCallback<Integer, BillsModel.Bills> callback) {


        RestClient.webServices().getCompletePartnerBills(params.key, 1, sortOrder, searchParam).enqueue(new Callback<ApiResponse<BillsModel>>() {
            @Override
            public void onResponse(Call<ApiResponse<BillsModel>> call, Response<ApiResponse<BillsModel>> response) {
                if (response.code() == 200) {
                    callback.onResult(response.body().getData().getBills(), null);

                }

            }

            @Override
            public void onFailure(Call<ApiResponse<BillsModel>> call, Throwable t) {

            }
        });
    }

这是我的适配器：

public class ApprovedBillsAdapter extends PagedListAdapter<BillsModel.Bills, ApprovedBillsAdapter.ItemViewHolder> {

    Context context;

    ApprovedBillsAdapter(Context context) {
        super(DIFF_CALLBACK);
        this.context = context;
    }

    @NonNull
    @Override
    public ApprovedBillsAdapter.ItemViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        return new ApprovedBillsAdapter.ItemViewHolder(LayoutInflater.from(context).inflate(R.layout.row_approved_bills, viewGroup, false));
    }

    @Override
    public void onBindViewHolder(@NonNull ApprovedBillsAdapter.ItemViewHolder holder, int i) {

        try {

            final BillsModel.Bills bill = getItem(i);
            holder.tv_bill_id.setText(bill.getBillId());
            Picasso.with(context).load(bill.getCustomer_image()).placeholder(R.drawable.ic_avatar).into(holder.ivUserImage);
            holder.tvCustomerName.setText(bill.getCustomer_name());
            holder.tvAmount.setText("Rs." + bill.getBillAmount());
            holder.tvMobileNumber.setText(bill.getCustomer_mobile());

            holder.itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {


                    Intent intent = new Intent(context, BillDetailsActivity.class);
                    intent.putExtra("id", bill.getId());
                    context.startActivity(intent);

                }
            });


            holder.tvPendingSinceValue.setText(bill.getUpdated_at());

        } catch (Exception e) {

        }
    }

    private static DiffUtil.ItemCallback<BillsModel.Bills> DIFF_CALLBACK =
            new DiffUtil.ItemCallback<BillsModel.Bills>() {
                @Override
                public boolean areItemsTheSame(BillsModel.Bills oldItem, BillsModel.Bills newItem) {
                    return oldItem.getBillId().equals(newItem.getBillId());
                }

                @Override
                public boolean areContentsTheSame(BillsModel.Bills oldItem, BillsModel.Bills newItem) {
                    return oldItem.equals(newItem);
                }
            };

    class ItemViewHolder extends RecyclerView.ViewHolder {

        TextView tv_bill_id;
        @BindView(R.id.iv_user_image)
        ImageView ivUserImage;
        @BindView(R.id.tv_customer_name)
        TextView tvCustomerName;
        @BindView(R.id.tv_mobile_number)
        TextView tvMobileNumber;

        @BindView(R.id.tv_bill_id)
        TextView tvBillId;

        @BindView(R.id.tv_amount)
        TextView tvAmount;
        @BindView(R.id.tv_pending_since_value)
        TextView tvPendingSinceValue;

        public ItemViewHolder(View itemView) {
            super(itemView);
            ButterKnife.bind(this, itemView);

            tv_bill_id = itemView.findViewById(R.id.tv_bill_id);

        }
    }

}

Answer 1

它解决了，我需要补充

 Integer key = params.key + 1;

  callback.onResult(response.body().getData().getOffers(), key);

到我的代码。每次加载时增加params.key后调用是关键。然后将其作为相邻键传递给onResult函数。