嵌套recylerview在开始几个滚动时滞后，然后平稳滚动？

Question

我正在使用嵌套的RecycerView。意思是在一个垂直的回收器视图中，我有多个水平的回收器视图

@Override
public void onBindViewHolder(final MainViewHolder holder, final int position) {
    switch (holder.getItemViewType()) {
        case TYPE_PRODUCT:
            ((ListHolderProduct) holder).itemTitle.setText(browseCategoryHomePageItems.get(position).displayName.toUpperCase());
            ((ListHolderProduct) holder).recyclerView.setAdapter(new CarouselProductsRecyclerAdapter(context
                    , browseCategoryHomePageItems.get(position).products
                    , R.layout.activity_categoryhome_products_grid_item
                    , nestedRecyclerItemClickedListener
                    , position));
            break;
        case TYPE_DEAL:
            ((ListHolderDeal) holder).itemTitle.setText(browseCategoryHomePageItems.get(position).displayName.toUpperCase());
            ((ListHolderDeal) holder).recyclerView.setAdapter(new CarouselDealsRecyclerAdapter(context
                    , browseCategoryHomePageItems.get(position).dealItems
                    , R.layout.activity_categoryhome_deals_grid_item
                    , nestedRecyclerItemClickedListener
                    , position));
            break;
            //few more types like this
    }
}

 layoutManager.setExtraLayoutSpace(2 * this.getResources().getDisplayMetrics().heightPixels);

public class PreCachingLayoutManager extends LinearLayoutManager {
private static final int DEFAULT_EXTRA_LAYOUT_SPACE = 600;
private int extraLayoutSpace = -1;
private Context context;

public PreCachingLayoutManager(Context context) {
    super(context);
    this.context = context;
}

public PreCachingLayoutManager(Context context, int extraLayoutSpace) {
    super(context);
    this.context = context;
    this.extraLayoutSpace = extraLayoutSpace;
}

public PreCachingLayoutManager(Context context, int orientation, boolean reverseLayout) {
    super(context, orientation, reverseLayout);
    this.context = context;
}

public void setExtraLayoutSpace(int extraLayoutSpace) {
    this.extraLayoutSpace = extraLayoutSpace;
}

@Override
protected int getExtraLayoutSpace(RecyclerView.State state) {
    if (extraLayoutSpace > 0) {
        return extraLayoutSpace;
    }
    return DEFAULT_EXTRA_LAYOUT_SPACE;
}

}

Answer 1

不要每次都在onBindViewholder中创建水平的适配器，而是在每个Viewholder类(ListHolderDeal，ListHolderProduct)中创建适当的适配器。然后，在垂直RecycerView的onbindViewholder中，只需替换该适配器的数据，如果水平RecycerView没有适配器，则用viewholder适配器设置该数据。如果是，则替换该适配器的数据集并调用NotifyDataSetChange。通过这种方法，您可以隐式地使用适配器池，这样GC就可以减少您的麻烦。

希望能有所帮助。