RecyclerView实现分批分页、上拉加载更多功能

RecyclerView越来越替代ListView，如何上拉加载更多呢？

Step 1：自定义Listener继承recyclerView的OnScrollListener

public abstract class EndLessOnScrollListener extends RecyclerView.OnScrollListener {

//声明一个LinearLayoutManager
private LinearLayoutManager mLinearLayoutManager;

//当前页，从0开始
private int currentPage = 0;

//已经加载出来的Item的数量
private int totalItemCount;

//主要用来存储上一个totalItemCount
private int previousTotal = 0;

//在屏幕上可见的item数量
private int visibleItemCount;

//在屏幕可见的Item中的第一个
private int firstVisibleItem;

//是否正在上拉数据
private boolean loading = true;

public EndLessOnScrollListener(LinearLayoutManager linearLayoutManager) {
this.mLinearLayoutManager = linearLayoutManager;
}

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

visibleItemCount = recyclerView.getChildCount();
totalItemCount = mLinearLayoutManager.getItemCount();
firstVisibleItem = mLinearLayoutManager.findFirstVisibleItemPosition();
if (loading) {

if (totalItemCount > previousTotal) {
//说明数据已经加载结束
loading = false;
previousTotal = totalItemCount;
}
}
//这里需要好好理解
if (!loading && totalItemCount - visibleItemCount <= firstVisibleItem) {
currentPage++;
onLoadMore(currentPage);
loading = true;
}
}

/**
* 提供一个抽闲方法，在Activity中监听到这个EndLessOnScrollListener
* 并且实现这个方法
*/
public abstract void onLoadMore(int currentPage);

}

Step 2：调用的地方

private Handler handler = new Handler();

mRecyclerView.addOnScrollListener(new EndLessOnScrollListener(mLinearLayoutManager) {
@Override
public void onLoadMore(int currentPage) {

if (pageIndex == pages) {
return;
}
showWaitDialog();
handler.postDelayed(new Runnable() {
public void run() {
//请求网络
pageIndex++;
getData();
mAdapter.notifyDataSetChanged();
}
}, 500);
}
});

就是这么方便简单；