public class ScrollToRecyclerView extends RecyclerView {//记录滚动的总距离，类似view中的mScrollX和mScrollYprivate int sx = 0, sy = 0;//自己定义的滚动监听接口public interface RecyclerScrollChangeListener{void ScrollChange(int y);}private RecyclerScrollChangeListener mScrollListener = null;public ScrollToRecyclerView(Context context) {super(context);addScrollListener();}public ScrollToRecyclerView(Context context, @Nullable AttributeSet attrs) {super(context, attrs);addScrollListener();}public ScrollToRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);addScrollListener();}//重写scrollTo方法，通过内部的scrollBy实现scrollTo的功能
    @Overridepublic void scrollTo(int x, int y) {super.scrollTo(x, y);//计算滚动的相对距离，通过传进来的x和当前的sx差值就是scrollBy需要滚动的值scrollBy(x - sx, y - sy);}//添加view的scrolllistener，在view滚动时根据滚动的距离自己计算sx，syprivate void addScrollListener(){addOnScrollListener(new OnScrollListener() {@Overridepublic void onScrolled(RecyclerView recyclerView, int dx, int dy) {
//                oldsx = sx;
//                oldsy = sy//因为dx和dy是相对上次的滚动距离，所以通过一开始的累加可以得到总的sx和sysx += dx;sy += dy;super.onScrolled(recyclerView, dx, dy);//此处如果有需要监听滚动变化的话在这回调if(mScrollListener != null){mScrollListener.ScrollChange(sy);}}});}//设置监听public void setRecyclerScrollListener(RecyclerScrollChangeListener scrollListener) {this.mScrollListener = scrollListener;}
}