如何将主单元放在StaggeredGridLayout的顶部(回收器视图)？

Question

我在我的Recycler View中使用StaggeredGridLayout

我需要的是：

​

​

我可以将回收器视图分成两列，但我不知道如何将主单元放在回收器视图的顶部

我不确定，但也许我可以把它放在容器中，并在滚动时尝试隐藏它？就像我们在用户开始向上滚动工具栏时对工具栏所做的那样。

但我不太确定

如何将主单元放在StaggeredGridLayout的顶部(回收器视图)？

提前感谢！

Answer 1

在onBindViewHolder方法中添加以下代码行

if(position == 0){
      StaggeredGridLayoutManager.LayoutParams layoutParams =  (StaggeredGridLayoutManager.LayoutParams) holder.itemView.getLayoutParams();
      layoutParams.setFullSpan(true);
}

Answer 2

最终，我的适配器可能会帮助人们理解它是如何工作的

public class AdapterRecViewMain
    extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

private List<BaseMarkerElement> mainCardList;
private final int HEADER_VIEW = 0;
private final int FOOTER_VIEW = 1;

public AdapterRecViewMain() {
}

public void setData(List<BaseMarkerElement> mainCardList) {
    this.mainCardList = mainCardList;
}

@Override public int getItemViewType(int position) {
    if (position == 0) {
        return HEADER_VIEW;
    }
    return FOOTER_VIEW;
}

@Override public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int type) {
    if (type == FOOTER_VIEW) {
        View v = LayoutInflater.from(viewGroup.getContext())
                .inflate(R.layout.card_main_activity, viewGroup, false);
        return new MainCardViewHolder(v);
    } else {
        View v = LayoutInflater.from(viewGroup.getContext())
                .inflate(R.layout.header_view_main_activity, viewGroup, false);
        return new HeaderViewHolder(v);
    }
}

@Override public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int positionItem) {
    final int position = viewHolder.getAdapterPosition();

    if (viewHolder instanceof HeaderViewHolder) {
        StaggeredGridLayoutManager.LayoutParams layoutParams =
                (StaggeredGridLayoutManager.LayoutParams) viewHolder.itemView.getLayoutParams();
        layoutParams.setFullSpan(true);

        BaseMarkerElement item = mainCardList.get(position);
        if (item instanceof HeaderView) {
            HeaderView header = (HeaderView) mainCardList.get(position);
            // need to add implementation
        }
    } else if (viewHolder instanceof MainCardViewHolder) {
        MainCardViewHolder currentView = (MainCardViewHolder) viewHolder;
        CardMainActivity currentCard = (CardMainActivity) mainCardList.get(position);

        currentView.ivMainCard.setImageResource(currentCard.getIvMainCard());
        currentView.tvBrandName.setText(currentCard.getTvBrandName());
        currentView.tvPrice.setText(currentCard.getTvPrice());
        currentView.tvType.setText(currentCard.getTvType());
    }
}

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

private class MainCardViewHolder extends RecyclerView.ViewHolder {
    ImageView ivMainCard;
    TextView tvBrandName;
    TextView tvType;
    TextView tvPrice;

    MainCardViewHolder(View view) {
        super(view);
        ivMainCard = (ImageView) view.findViewById(R.id.imageViewMainCard);
        tvBrandName = (TextView) view.findViewById(R.id.tvBrandName);
        tvType = (TextView) view.findViewById(R.id.tvType);
        tvPrice = (TextView) view.findViewById(R.id.tvPrice);
    }
}

private class HeaderViewHolder extends RecyclerView.ViewHolder {

    public HeaderViewHolder(View itemView) {
        super(itemView);

    }
}
}