@kushal @abdulaziz

为什么不使用这个逻辑呢?

public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    int totalItemCount, lastVisibleItemPosition;

    if (dy > 0) {
      totalItemCount = _layoutManager.getItemCount();
      lastVisibleItemPosition = _layoutManager.findLastVisibleItemPosition();

      if (!_isLastItem) {
        if ((totalItemCount - 1) == lastVisibleItemPosition) {
          LogUtil.e("end_of_list");

          _isLastItem = true;
        }
      }
    }
  }

我有一个关于如何使用RecyclerView进行分页的非常详细的示例。在高层次，我有一个设置PAGE_SIZE，让我们说30。所以我请求30个项目，如果我得到30个，我就请求下一页。如果我得到的条目少于30个，我就标记一个变量来指示已经到达最后一页，然后停止请求更多的页面。看看吧，告诉我你的想法。

https://medium.com/@etiennelawlor/pagination-with-recyclerview-1cb7e66a502b

感谢@Kushal，这是我实现它的方式

private boolean loading = true;
int pastVisiblesItems, visibleItemCount, totalItemCount;

mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        if (dy > 0) { //check for scroll down
            visibleItemCount = mLayoutManager.getChildCount();
            totalItemCount = mLayoutManager.getItemCount();
            pastVisiblesItems = mLayoutManager.findFirstVisibleItemPosition();

            if (loading) {
                if ((visibleItemCount + pastVisiblesItems) >= totalItemCount) {
                    loading = false;
                    Log.v("...", "Last Item Wow !");
                    // Do pagination.. i.e. fetch new data

                    loading = true;
                }
            }
        }
    }
});

别忘了加上

LinearLayoutManager mLayoutManager;
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);

没有重复调用，但你滚动。fetchData只会在您位于列表的末尾并且有更多数据要获取时调用

关于我的代码: 1.fetchData()每次调用取10个项。 2.isScrolling是一个类成员变量 3.previousTotalCount也是类成员。它存储以前访问过的最后一个项目

recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
            override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
                super.onScrollStateChanged(recyclerView, newState)
                if (newState == AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL) {
                    isScrolling = true
                }
            }

            override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
                super.onScrolled(recyclerView, dx, dy)

                val visibleItemCount = layoutManager.childCount
                val totalItemCount = layoutManager.itemCount
                val scrolledOutItems = layoutManager.findFirstVisibleItemPosition()


                if (isScrolling && (visibleItemCount + scrolledOutItems == totalItemCount)
                    && (visibleItemCount + scrolledOutItems != previousTotalCount)) {
                    previousTotalCount = totalItemCount              
                    isScrolling = false
                    fetchData()  //fetches 10 new items from Firestore
                    pagingProgressBar.visibility = View.VISIBLE
                }
            }
        })

做这些变量。

private int previousTotal = 0;
private boolean loading = true;
private int visibleThreshold = 5;
int firstVisibleItem, visibleItemCount, totalItemCount;

设置为滚动回收视图。

mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {

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

        visibleItemCount = mRecyclerView.getChildCount();
        totalItemCount = mLayoutManager.getItemCount();
        firstVisibleItem = mLayoutManager.findFirstVisibleItemPosition();

        if (loading) {
            if (totalItemCount > previousTotal) {
                loading = false;
                previousTotal = totalItemCount;
            }
        }
        if (!loading && (totalItemCount - visibleItemCount) 
            <= (firstVisibleItem + visibleThreshold)) {
            // End has been reached

            Log.i("Yaeye!", "end called");

            // Do something

            loading = true;
        }
    }
});

注意:确保你使用LinearLayoutManager作为RecyclerView的布局管理器。

LinearLayoutManager mLayoutManager;
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);

对于网格来说

GridLayoutManager mLayoutManager;
mLayoutManager = new GridLayoutManager(getActivity(), spanCount);
mRecyclerView.setLayoutManager(mLayoutManager);

有乐趣与你无尽的卷轴!!^ ^。

更新:mRecyclerView.setOnScrollListener()已弃用，只需替换为mRecyclerView.addOnScrollListener()，警告将消失!你可以从这个SO问题中读到更多。

由于Android现在正式支持Kotlin，这里是相同的更新-

使OnScrollListener

class OnScrollListener(val layoutManager: LinearLayoutManager, val adapter: RecyclerView.Adapter<RecyclerAdapter.ViewHolder>, val dataList: MutableList<Int>) : RecyclerView.OnScrollListener() {
    var previousTotal = 0
    var loading = true
    val visibleThreshold = 10
    var firstVisibleItem = 0
    var visibleItemCount = 0
    var totalItemCount = 0

    override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
        super.onScrolled(recyclerView, dx, dy)

        visibleItemCount = recyclerView.childCount
        totalItemCount = layoutManager.itemCount
        firstVisibleItem = layoutManager.findFirstVisibleItemPosition()

        if (loading) {
            if (totalItemCount > previousTotal) {
                loading = false
                previousTotal = totalItemCount
            }
        }

        if (!loading && (totalItemCount - visibleItemCount) <= (firstVisibleItem + visibleThreshold)) {
            val initialSize = dataList.size
            updateDataList(dataList)
            val updatedSize = dataList.size
            recyclerView.post { adapter.notifyItemRangeInserted(initialSize, updatedSize) }
            loading = true
        }
    }
}

然后像这样把它添加到你的RecyclerView中

recyclerView.addOnScrollListener(OnScrollListener(layoutManager, adapter, dataList))

要获得完整的代码示例，请参阅Github repo。

检查的每一件事都有详细的解释: 使用RecyclerView从A到Z分页

    mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
    @Override
    public void onScrollStateChanged(RecyclerView recyclerView,
                                     int newState) {
        super.onScrollStateChanged(recyclerView, newState);
    }

    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);
        int visibleItemCount = mLayoutManager.getChildCount();
        int totalItemCount = mLayoutManager.getItemCount();
        int firstVisibleItemPosition = mLayoutManager.findFirstVisibleItemPosition();

        if (!mIsLoading && !mIsLastPage) {
            if ((visibleItemCount + firstVisibleItemPosition) >= totalItemCount
                    && firstVisibleItemPosition >= 0) {
                loadMoreItems();
            }
        }
    }
})

loadMoreItems ():

private void loadMoreItems() {
    mAdapter.removeLoading();
    //load data here from the server

    // in case of success
    mAdapter.addData(data);
    // if there might be more data
    mAdapter.addLoading();
}

在MyAdapter中:

private boolean mIsLoadingFooterAdded = false;

public void addLoading() {
    if (!mIsLoadingFooterAdded) {
        mIsLoadingFooterAdded = true;
        mLineItemList.add(new LineItem());
        notifyItemInserted(mLineItemList.size() - 1);
    }
}

public void removeLoading() {
    if (mIsLoadingFooterAdded) {
        mIsLoadingFooterAdded = false;
        int position = mLineItemList.size() - 1;
        LineItem item = mLineItemList.get(position);

        if (item != null) {
            mLineItemList.remove(position);
            notifyItemRemoved(position);
        }
    }
}

public void addData(List<YourDataClass> data) {

    for (int i = 0; i < data.size(); i++) {
        YourDataClass yourDataObject = data.get(i);
        mLineItemList.add(new LineItem(yourDataObject));
        notifyItemInserted(mLineItemList.size() - 1);
    }
}