Question

我有一个可扩展的Recycler，我从服务器获取数据，我检查日志，我得到的数据是正确的，现在当我尝试设置适配器时，我收到了这个错误

java.lang.NullPointerException：尝试调用接口方法 null对象上的'java.util.Iterator java.util.List.iterator（）' 参考

这是我的片段

  private List<GetInboxByUserNameModel.DATum> messageslist;
  private GetInboxByUserNameModel getInboxByUserNameModel;
  private RecyclerView recyclerView;

  messageslist = new ArrayList<>();
  getInboxByUserNameModel = (GetInboxByUserNameModel) responseObject;
  messageslist = getInboxByUserNameModel.getDATA();
  implementAdapter(messageslist);


  private void implementAdapter(List<GetInboxByUserNameModel.DATum> categoriesList) {
        if (categoriesList == null) {
            AlertView.showOneButtonAlert(getActivity(), getActivity(), "", getString(R.string.no_data), getString(R.string.ok), null);
            return;
        }
        if (categoriesList.size() == 0) {
            AlertView.showOneButtonAlert(getActivity(), getActivity(), "", getString(R.string.no_data), getString(R.string.ok), null);
            return;
        }
        mAdapter = new RecipeAdapterForInbox_Test(getActivity(), categoriesList);
        mAdapter.setExpandCollapseListener(new ExpandableRecyclerAdapter.ExpandCollapseListener() {
            @UiThread
            @Override
            public void onParentExpanded(int parentPosition) {
            }

            @UiThread
            @Override
            public void onParentCollapsed(int parentPosition) {
            }
        });
        recyclerView.setAdapter(mAdapter);
        recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
    }

这是我的ExpandableRecyclerAdapter

 public class RecipeAdapterForInbox_Test extends ExpandableRecyclerAdapter<GetInboxByUserNameModel.DATum, GetInboxByUserNameModel.MESSAGES, ViewHolderParentInbox, ViewHolderChildinbox> {

    private LayoutInflater mInflater;
    private Activity activity;
    private Context context;
    List<GetInboxByUserNameModel.DATum> daTa;

    public RecipeAdapterForInbox_Test(Activity activity, List<GetInboxByUserNameModel.DATum> recipeList) {
        super(recipeList);
        this.daTa = recipeList;
        this.activity = activity;
        this.context = activity;
        mInflater = LayoutInflater.from(context);
    }

    @UiThread
    @Override
    public ViewHolderParentInbox onCreateParentViewHolder(@NonNull ViewGroup parentViewGroup, int viewType) {
        View recipeView = mInflater.inflate(R.layout.new_adapter_available_parent, parentViewGroup, false);
        return new ViewHolderParentInbox(recipeView, context);
    }

    @UiThread
    @Override
    public ViewHolderChildinbox onCreateChildViewHolder(@NonNull ViewGroup childViewGroup, int viewType) {
        View ingredientView = mInflater.inflate(R.layout.new_adapter_available_child, childViewGroup, false);
        return new ViewHolderChildinbox(ingredientView);
    }

    @UiThread
    @Override
    public void onBindParentViewHolder(@NonNull ViewHolderParentInbox holder, int parentPosition, @NonNull GetInboxByUserNameModel.DATum model) {
        holder.headerNameTextView.setText(model.getbILLINGNUMBER());
    }

    @UiThread
    @Override
    public void onBindChildViewHolder(@NonNull ViewHolderChildinbox holder, int parentPosition, int childPosition, final GetInboxByUserNameModel.MESSAGES model) {
        holder.childTextview.setText(model.getbRIEF());
//        holder.activateButton.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View v) {
//                goDialog(model);
//            }
//        });
    }

我使用了调试，问题就在这里

    super(recipeList);

如果有人对此有任何疑问，请帮助我

Answer 1

由于组内的子列表为null，因此您发现此错误。请遍历messageslist并检查该组并获取子列表。

无法设置适配器ExpandableRecyclerAdapter android

1 个答案: