Question

当我（使用Google邮件）登录时，LoginFragment被包含DrinkCategoryFragment的{{1}}取代。

可以从Firebase数据库正确获取项目，但是布局不存在，我不知道为什么。

RecyclerView在RecyclerView内部初始化：

DrinkCategoriesViewMvcImpl.java

这是适配器类：

public class DrinkCategoriesViewMvcImpl implements DrinkCategoriesViewMvc {

    private View rootView;
    private RecyclerView recyclerView;
    private FloatingActionButton shareButton;

    private DrinkCategoriesAdapter adapter;

    public DrinkCategoriesViewMvcImpl(LayoutInflater inflater, ViewGroup parent) {
        initializeViews(inflater, parent);
    }

    @Override
    public View getRootView() {
        return rootView;
    }

    @Override
    public void setOnDrinkCategoryClickListener(OnDrinkCategoryClickListener listener) {

    }

    @Override
    public void bindDrinkCategories(List<DrinkCategory> drinkCategories) {
        adapter.addDrinkCategories(drinkCategories);
        adapter.notifyDataSetChanged();
    }

    private void initializeViews(LayoutInflater inflater, ViewGroup parent) {
        rootView = inflater.inflate(R.layout.activity_main_list, parent, false);
        shareButton = rootView.findViewById(R.id.fab_share);
        setupRecyclerView();
    }

    private void setupRecyclerView() {
        recyclerView = rootView.findViewById(R.id.recyclerView);
        LinearLayoutManager layoutManager = new LinearLayoutManager(rootView.getContext(),LinearLayoutManager.VERTICAL,false);
        recyclerView.setLayoutManager(layoutManager);
        recyclerView.setHasFixedSize(true);
        adapter = new DrinkCategoriesAdapter(rootView.getContext());
        recyclerView.setAdapter(adapter);
    }

还有布局文件：

public class DrinkCategoriesAdapter extends RecyclerView.Adapter<DrinkCategoriesAdapter.CategoryItemHolder> {

    private Context context;
    private List<DrinkCategory> drinkCategories;

    public DrinkCategoriesAdapter(Context context) {
        this.context = context;
    }

    public void addDrinkCategories(List<DrinkCategory> drinkCategories) {
        this.drinkCategories = drinkCategories;
    }

    @NonNull
    @Override
    public CategoryItemHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(context).inflate(R.layout.activity_main_list_item, parent, false);
        return new CategoryItemHolder(itemView);
    }

    @Override
    public void onBindViewHolder(@NonNull CategoryItemHolder holder, int position) {
        if (drinkCategories != null && drinkCategories.size() > 0) {
            holder.bindViews(drinkCategories.get(position));
        }
    }

    @Override
    public int getItemCount() {
        if (drinkCategories != null) {
            return drinkCategories.size();
        }
        return 0;
    }

    class CategoryItemHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

        private TextView title, subtitle;
        private ImageView_3_2 poster;

        public CategoryItemHolder(View itemView) {
            super(itemView);
            itemView.setOnClickListener(this);
            title = itemView.findViewById(R.id.textview_title);
            subtitle = itemView.findViewById(R.id.textview_subtitle);
            poster = itemView.findViewById(R.id.imageview_background);
        }

        @Override
        public void onClick(View v) {

        }

        public void bindViews(DrinkCategory drinkCategory) {
            title.setText(drinkCategory.getTitle());
            //  TODO: subtitle will be set from sharedpreferences
        }
    }
}

为什么会这样？（project on Github）

Answer 1

您需要检查您的 DrinkCategoryFragment 类。

由于您没有返回要放大的视图

 @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        viewMvc = new DrinkCategoriesViewMvcImpl(inflater, container);
        // Not return the view you want to inflate
        return super.onCreateView(inflater, container, savedInstanceState);
    }

尝试它对您有用

 @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        viewMvc = new DrinkCategoriesViewMvcImpl(inflater, container);
        return viewMvc.getRootView();
    }

Android的RecyclerView Adapter方法未调用

1 个答案: