Android菜谱APP：如何实现RecyclerView获取用户输入并编辑食材项

1. 修正布局结构 #

确保横向RecyclerView与EditText上下排列，RecyclerView需指定横向布局方向：

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/ingredients_recycler"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

    <EditText
        android:id="@+id/et_ingredient"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="输入食材后按回车添加"/>
</LinearLayout>

2. 处理EditText回车添加逻辑 #

无需使用TextWatcher，直接监听回车键事件，触发食材添加：

EditText etIngredient = findViewById(R.id.et_ingredient);
etIngredient.setOnKeyListener((v, keyCode, event) -> {
    if (keyCode == KeyEvent.KEYCODE_ENTER && event.getAction() == KeyEvent.ACTION_UP) {
        String ingredient = etIngredient.getText().toString().trim();
        if (!ingredient.isEmpty()) {
            ingredientList.add(ingredient);
            adapter.notifyItemInserted(ingredientList.size() - 1);
            etIngredient.setText("");
        }
        return true;
    }
    return false;
});

3. 完善RecyclerView Adapter实现删除功能 #

Adapter需绑定数据集并提供删除回调，每个Item包含食材文本和删除按钮：

public class IngredientAdapter extends RecyclerView.Adapter<IngredientAdapter.ViewHolder> {
    private List<String> ingredientList;
    private OnDeleteListener deleteListener;

    public interface OnDeleteListener {
        void onDelete(int position);
    }

    public IngredientAdapter(List<String> list, OnDeleteListener listener) {
        this.ingredientList = list;
        this.deleteListener = listener;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.item_ingredient, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        holder.tvIngredient.setText(ingredientList.get(position));
        holder.btnDelete.setOnClickListener(v -> deleteListener.onDelete(position));
    }

    @Override
    public int getItemCount() {
        return ingredientList.size();
    }

    static class ViewHolder extends RecyclerView.ViewHolder {
        TextView tvIngredient;
        ImageView btnDelete;

        ViewHolder(@NonNull View itemView) {
            super(itemView);
            tvIngredient = itemView.findViewById(R.id.tv_ingredient);
            btnDelete = itemView.findViewById(R.id.btn_delete);
        }
    }
}

对应的Item布局（item_ingredient.xml）：

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:padding="8dp"
    android:background="#f5f5f5"
    android:layout_marginEnd="8dp">

    <TextView
        android:id="@+id/tv_ingredient"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="16sp"
        android:paddingEnd="8dp"/>

    <ImageView
        android:id="@+id/btn_delete"
        android:layout_width="20dp"
        android:layout_height="20dp"
        android:src="@drawable/ic_delete"/>
</LinearLayout>

4. 初始化RecyclerView与数据集 #

在Activity/Fragment中完成初始化，绑定删除逻辑：

List<String> ingredientList = new ArrayList<>();
IngredientAdapter adapter = new IngredientAdapter(ingredientList, position -> {
    ingredientList.remove(position);
    adapter.notifyItemRemoved(position);
});

RecyclerView recyclerView = findViewById(R.id.ingredients_recycler);
recyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false));
recyclerView.setAdapter(adapter);

常见问题排查 #

• RecyclerView不显示：确认已设置横向LinearLayoutManager
• 回车无响应：检查按键监听中event.getAction() == KeyEvent.ACTION_UP的判断，避免重复触发
• 删除失效：确认Adapter的删除回调已正确实现，且调用了notifyItemRemoved

内容的提问来源于stack exchange，提问作者Emtenan YYC