Android 在Recyclerview中使用滑动刷新方法加载上一页注释

我想知道如何在recyclerview上使用swipe to refresh方法加载上一页的项目。似乎在任何地方都找不到解决办法。我创建了一个应用程序，其中包含一个无休止的Recyclerview，其中包含来自在线论坛的数据。当用户一直向下滚动到底部时，它将加载下一页并填充recyclerview上的下一条注释。它工作得很好

现在我想实现同样的目标，但是当用户滚动到顶部时，加载上一页。我希望用户执行一次滑动，这将加载上一页，并使用顶部的上一条注释填充recyclerview。我该怎么做

MainActivity.java

private ArrayList<CommentItem> commentsList = new ArrayList<CommentItem>();
private RecyclerAdapter adapter_thread;
private int pageNumber = 1;

//recyclerview initialization have been done here

adapter_replies.setOnLoadMoreListener(new OnLoadMoreListener() {
        @Override
        public void onLoadMore() {

            commentsList.add(null); //to show progressbar at the bottom while loading the next page
            adapter_thread.notifyItemInserted(commentsList.size() - 1);
            ++pageNumber;
            getComments(); //async task load next page comments

        }
    });

private boolean loading;
private OnLoadMoreListener onLoadMoreListener;
private int visibleThreshold = 1;

public RecyclerAdapter(Context context, final ArrayList<CommentItem> commentsList, RecyclerView recyclerView) {
this.commentsList= commentsList;
this.context = context;

if (recyclerView.getLayoutManager() instanceof LinearLayoutManager) {

    final LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView
            .getLayoutManager();


    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
                @Override
                public void onScrolled(RecyclerView recyclerView,
                                       int dx, int dy) {
                    super.onScrolled(recyclerView, dx, dy);

                    totalItemCount = linearLayoutManager.getItemCount();
                    lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition();
                    firstVisibleItem = linearLayoutManager.findFirstVisibleItemPosition();
                    verylastVisibleItem = linearLayoutManager.findLastCompletelyVisibleItemPosition();

                    if (!loading && totalItemCount <= (lastVisibleItem + visibleThreshold)) {

                        if (onLoadMoreListener != null) {
                            onLoadMoreListener.onLoadMore();

                        }

                        loading = true;

                    }

                }
            });

}

private ArrayList commentsList=new ArrayList（）；
专用回收适配器\u线程；
私有int pageNumber=1；
//recyclerview初始化已在此处完成
adapter_responses.setOnLoadMoreListener（新的OnLoadMoreListener（）{
@凌驾
public void onLoadMore（）{
commentsList.add（null）；//加载下一页时在底部显示progressbar
适配器\u thread.notifyItemInserted（commentsList.size（）-1）；
++页码；
getComments（）；//异步任务加载下一页注释
}
});

RecyclerAdapter.java

private ArrayList<CommentItem> commentsList = new ArrayList<CommentItem>();
private RecyclerAdapter adapter_thread;
private int pageNumber = 1;

//recyclerview initialization have been done here

adapter_replies.setOnLoadMoreListener(new OnLoadMoreListener() {
        @Override
        public void onLoadMore() {

            commentsList.add(null); //to show progressbar at the bottom while loading the next page
            adapter_thread.notifyItemInserted(commentsList.size() - 1);
            ++pageNumber;
            getComments(); //async task load next page comments

        }
    });

private boolean loading;
private OnLoadMoreListener onLoadMoreListener;
private int visibleThreshold = 1;

public RecyclerAdapter(Context context, final ArrayList<CommentItem> commentsList, RecyclerView recyclerView) {
this.commentsList= commentsList;
this.context = context;

if (recyclerView.getLayoutManager() instanceof LinearLayoutManager) {

    final LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView
            .getLayoutManager();


    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
                @Override
                public void onScrolled(RecyclerView recyclerView,
                                       int dx, int dy) {
                    super.onScrolled(recyclerView, dx, dy);

                    totalItemCount = linearLayoutManager.getItemCount();
                    lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition();
                    firstVisibleItem = linearLayoutManager.findFirstVisibleItemPosition();
                    verylastVisibleItem = linearLayoutManager.findLastCompletelyVisibleItemPosition();

                    if (!loading && totalItemCount <= (lastVisibleItem + visibleThreshold)) {

                        if (onLoadMoreListener != null) {
                            onLoadMoreListener.onLoadMore();

                        }

                        loading = true;

                    }

                }
            });

}

私有布尔加载；
私有OnLoadMoreListener OnLoadMoreListener；
私有int visibleThreshold=1；
公共RecyclerAdapter（上下文上下文、最终ArrayList注释列表、RecyclerView RecyclerView）{
this.commentsList=commentsList；
this.context=上下文；
if（recyclerView.getLayoutManager（）实例的LinearLayoutManager）{
最终LinearLayoutManager LinearLayoutManager=（LinearLayoutManager）回收视图
.getLayoutManager（）；
recyclerView.addOnScrollListener（新的recyclerView.OnScrollListener（）{
@凌驾
已填空的公共空间（RecyclerView RecyclerView，
整数dx，整数dy）{
super.onScrolled（recyclerView、dx、dy）；
totalItemCount=linearLayoutManager.getItemCount（）；
lastVisibleItem=linearLayoutManager.findLastVisibleItemPosition（）；
firstVisibleItem=linearLayoutManager.findFirstVisibleItemPosition（）；
verylastVisibleItem=linearLayoutManager.findLastCompletelyVisibleItemPosition（）；
如果（！loading&&totalItemCount您可以使用Hi，谢谢我正在使用它。实际上，我关心的是我不确定如何将上一页的注释添加到当前列表的顶部。以及如何在加载适配器后通知适配器。创建数组列表将其传递给适配器，然后将注释列表添加到ar中您已传递给适配器并调用适配器的raylit.notifyDatasetChanged（）若要按相反顺序显示它们，您可以反转arraylist或将LinearLayoutManager反向布局设置为true，给定的链接将帮助您