分段回收视图答案

【问题标题】：Sectioned recyclerview分段回收视图
【发布时间】：2016-04-09 08:00:22
【问题描述】：

我正在尝试使用部分和子标题来实现 recyclerview。我在 Github 上通过Gabriele Mariotti 找到了一个不错的课程，但我在实现它时遇到了一些问题。基本上，当我使用常规的 recyclerview 适配器而不是示例时，每个部分标题都会替换我的 recyclerview 的一个元素。

例如。假设我的 recyclerview 中有 5 张卡片（5 种成分，因为它是一个烹饪应用程序），但是在添加 2 个标题后，现在我剩下 3 张卡片，其中第一个和第四个被子标题替换。我希望这是有道理的。我的卡片位置也乱七八糟了，当我滚动到回收站视图的底部时，它会使应用程序崩溃。我附上了几行代码，希望有人能指出我正确的方向。与 Mariotti 的示例相比，我基本上只是使用自己的适配器而不是“simpleadapter.java”类：

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.RecyclerViewHolders> {

private List<Ingredient> itemList;
private final String TAG = OrderFragment.class.getSimpleName();
private Context context;

public RecyclerViewAdapter(Context context,  List<Ingredient> itemList) {
    this.itemList = itemList;
    this.context = context;
}

public class RecyclerViewHolders extends RecyclerView.ViewHolder{
    public RecyclerViewHolders(View itemView) {
        super(itemView);
    }
}

public class ingredientViewHolder extends RecyclerViewHolders{

    public TextView ingredientName;
    public ImageView ingredientPhoto;
    public ImageButton infoBtn;
    public Button regularBtn;
    public Button extraBtn;
    public ImageView soldOutPhoto;
    public ImageView grayOutPhoto;
    private Context context;

    public ingredientViewHolder(View itemView) {
        super(itemView);
        ingredientName = (TextView)itemView.findViewById(R.id.ingredient_name);
        ingredientPhoto = (ImageView)itemView.findViewById(R.id.ingredient_photo);
        infoBtn = (ImageButton) itemView.findViewById(R.id.info);
        regularBtn = (Button) itemView.findViewById(R.id.regular);
        extraBtn = (Button) itemView.findViewById(R.id.extra);
        soldOutPhoto = (ImageView) itemView.findViewById(R.id.sold_out);
        grayOutPhoto = (ImageView) itemView.findViewById(R.id.gray_out);
    }
}

@Override
public RecyclerViewHolders onCreateViewHolder(ViewGroup parent, int viewType) {
    View layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.ingredient, null);
    return new ingredientViewHolder(fragment, layoutView);
}

@Override
public void onBindViewHolder(RecyclerViewHolders viewHolder, final int pos) {
    ingredientViewHolder holder = (ingredientViewHolder) viewHolder;

    final int position = holder.getAdapterPosition();
    final String name = itemList.get(position).getName();

    if (MainActivity.order.get(position ) == 1) {
        holder.regularBtn.setSelected(true);
        holder.extraBtn.setSelected(false);
    } else if (MainActivity.order.get(position ) == 2) {
        holder.regularBtn.setSelected(false);
        holder.extraBtn.setSelected(true);
    } else {
        holder.regularBtn.setSelected(false);
        holder.extraBtn.setSelected(false);
    }

    holder.ingredientName.setText(itemList.get(position).getName());

}

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

这就是我在片段中如何调用这个 recyclerview：

        final RecyclerView rView = (RecyclerView) v.findViewById(R.id.recycler_view);
    rView.setHasFixedSize(true);
    rView.setLayoutManager(new GridLayoutManager(getActivity(), 3));

    //Your RecyclerView.Adapter
    RecyclerView.Adapter rcAdapter = new RecyclerViewAdapter(getActivity(),  visibleIngredients);
    //This is the code to provide a sectioned grid
    List<SectionedGridRecyclerViewAdapter.Section> sections =
            new ArrayList<SectionedGridRecyclerViewAdapter.Section>();

    //Sections
    sections.add(new SectionedGridRecyclerViewAdapter.Section(0,"Spreads"));
    sections.add(new SectionedGridRecyclerViewAdapter.Section(2,"Liquid"));

    //Add your adapter to the sectionAdapter
    SectionedGridRecyclerViewAdapter.Section[] dummy = new SectionedGridRecyclerViewAdapter.Section[sections.size()];
    SectionedGridRecyclerViewAdapter mSectionedAdapter = new
            SectionedGridRecyclerViewAdapter(getActivity(),R.layout.section,R.id.section_text,rView,rcAdapter);
    mSectionedAdapter.setSections(sections.toArray(dummy));

    //Apply this adapter to the RecyclerView
    rView.setAdapter(mSectionedAdapter);

【问题讨论】：

发布您的堆栈跟踪

标签： android android-recyclerview adapter

【解决方案1】：

找出问题所在。看起来该位置已关闭，因为在 onBindViewHolder 内部我使用了以下行：

final int position = holder.getAdapterPosition();

一旦我忽略了这一点并使用函数返回的位置，一切都很好。

【讨论】：