Question

我发现在StackOverflow上只有一些与此问题相关的文章尝试了各种组合的所有解决方案，但无法让RecyclerView显示我的RecyclerView.Adapter填充了我可以验证的数据，并在调试模式下查看列表，但它只是不会显示信息。

我的代码（我很难粘贴XML布局文件）：

public class RecipeDetailActivity extends AppCompatActivity {
    private RecipeModel mRecipe;
    private ArrayList<IngredientModel> mIngredientList = new ArrayList<>();
    private IngredientListAdapter ingredientListAdapter;
    private RecyclerView rvIngredientList;
    private boolean mTwoPane;
    private ListView listView;

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

        rvIngredientList = (RecyclerView)findViewById(R.id.rv_ingredient_list);
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        rvIngredientList.setLayoutManager(layoutManager);
        SampleRecycler sampleRecycler = new SampleRecycler(); // empty RecyclerView.Adapter
        rvIngredientList.setAdapter(sampleRecycler);

        mRecipe = getIntent().getParcelableExtra("com.wernerraubenheimer.bakingapp.data.RecipeModel");

        mIngredientList = mRecipe.getIngredients();
        ingredientListAdapter = new IngredientListAdapter(mIngredientList);
        ingredientListAdapter.notifyDataSetChanged();
        // Up until this point the RecyclerVie.Adapter is populated with data - debug mode I can see the list
        rvIngredientList.swapAdapter(ingredientListAdapter, false);
    }
}

public class IngredientListAdapter extends RecyclerView.Adapter<IngredientListAdapter.IngredientViewHolder> {
    private ArrayList<IngredientModel> mIngredientList;
    private Context mContext;
    private boolean mTwoPane;

    public IngredientListAdapter(ArrayList<IngredientModel> ingredientList) {
        mIngredientList = ingredientList;
    }

    @Override
    public IngredientViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        mContext = parent.getContext();
        int layoutIdForListItem = R.layout.ingredient_list_item;
        LayoutInflater inflater = LayoutInflater.from(mContext);
        boolean attachImmediatelyToParent = false;

        View view = inflater.inflate(layoutIdForListItem, parent, attachImmediatelyToParent);
        IngredientViewHolder viewHolder = new IngredientViewHolder(view);

        return viewHolder;
    }

    @Override
    public void onBindViewHolder(IngredientViewHolder holder, int position) {
        IngredientModel ingredient = mIngredientList.get(position);
        holder.bind(mContext, ingredient);
    }

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

    static class IngredientViewHolder extends RecyclerView.ViewHolder {
        private CardView cardviewContainer;
        private TextView tvIngredientName;
        private TextView tvIngredientQuantity;
        private TextView tvIngredientMeasure;
        private Context mContext;
        private IngredientModel mIngredient;

        IngredientViewHolder(View itemView) {
            super(itemView);

            //cardviewContainer = (CardView)itemView.findViewById(R.id.card_view_ingredient);
            tvIngredientName = (TextView)itemView.findViewById(R.id.text_view_ingredient_name);
            tvIngredientQuantity =(TextView)itemView.findViewById(R.id.text_view_quantity);
            tvIngredientMeasure = (TextView)itemView.findViewById(R.id.text_view_measure);
        }

        void bind(Context context, IngredientModel ingredientModel) {
            mContext = context;
            mIngredient = ingredientModel;

            tvIngredientName.setText(mIngredient.getIngredient());
            tvIngredientQuantity.setText(mIngredient.getQuantity());
            tvIngredientMeasure.setText(mIngredient.getMeasure());
        }
    }
}

Answer 1

虽然很难从您粘贴的代码中解读，看起来问题在于以下功能：

@OneOf(values = "12-14m, 16m, 18m")
private String size;

将条件更改为@Override public int getItemCount() { if (mIngredientList != null) { return 0; } else { return mIngredientList.size(); } }可以解决问题。

此外，在if (mIngredientList == null) {方法中，只有以下代码才足以显示列表：

RecipeDetailActivity.onCreate()

Android Studio：E / RecyclerView：没有连接适配器;跳过布局

1 个答案: