RecyclerView向我們提供了若干個(gè)方法來(lái)進(jìn)行滾動(dòng)：
(1).scrollTo(int x, int y)
Set the scrolled position of your view.
(2).scrollBy(int x, int y)
Move the scrolled position of your view.
(3).scrollToPosition(int position)
Convenience method to scroll to a certain position. RecyclerView does not implement scrolling logic, rather forwards the call to RecyclerView.LayoutManager.scrollToPosition(int)
前面2個(gè)方法需要我們?nèi)タ刂埔苿?dòng)的距離卧须，自己計(jì)算高度或者寬度弄痹。在動(dòng)態(tài)的布局中且各項(xiàng)樣式高度可能都不一樣的情況下设拟，比較有難度程储。
使用第3個(gè)方法scrollToPosition時(shí)蹭沛，移動(dòng)到當(dāng)前屏幕可見(jiàn)列表的前面的項(xiàng)時(shí)，它會(huì)將要顯示的項(xiàng)置頂章鲤。但是移動(dòng)到后面的項(xiàng)時(shí)摊灭，一般會(huì)顯示在最后的位置。
因此败徊，綜合以上兩個(gè)方法帚呼，我們可以先用scrollToPosition方法，將要置頂?shù)捻?xiàng)先移動(dòng)顯示出來(lái)集嵌，然后計(jì)算這一項(xiàng)離頂部的距離萝挤，用scrollBy完成最后距離的滾動(dòng)。

1.讓置頂?shù)哪且豁?xiàng)在當(dāng)前屏幕可見(jiàn)

private void scrollToNextShotDate(List<BabyVaccineGroup> vaccineGroupList) {
        LinearLayoutManager linearLayoutManager = (LinearLayoutManager) getRecyclerView().getLayoutManager();
        //獲取當(dāng)前RecycleView屏幕可見(jiàn)的第一項(xiàng)和最后一項(xiàng)的Position
        int firstVisibleItemPosition = linearLayoutManager.findFirstVisibleItemPosition();
        int lastVisibleItemPosition = linearLayoutManager.findLastVisibleItemPosition();
        if (nextPosition < firstVisibleItemPosition) {
            //要置頂?shù)捻?xiàng)在當(dāng)前顯示的第一項(xiàng)之前
            getRecyclerView().smoothScrollToPosition(nextShotPosition);
        } else if (nextPosition < lastVisibleItemPosition) {
            //要置頂?shù)捻?xiàng)已經(jīng)在屏幕上顯示根欧，計(jì)算它離屏幕原點(diǎn)的距離
            int top = getRecyclerView().getChildAt(nextShotPosition - firstVisibleItemPosition).getTop();
            getRecyclerView().smoothScrollBy(0, top);
        } else {
            //要置頂?shù)捻?xiàng)在當(dāng)前顯示的最后一項(xiàng)之后
            mShouldScroll = true;
            getRecyclerView().smoothScrollToPosition(nextShotPosition);
        }
    }

2.添加滾動(dòng)監(jiān)聽(tīng)怜珍，當(dāng)完成第一次滾動(dòng)后，進(jìn)行第二次的滾動(dòng)

private class RcvScrollListener extends RecyclerView.OnScrollListener {
        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            if (mShouldScroll && newState == RecyclerView.SCROLL_STATE_IDLE) {
                mShouldScroll = false;
                LinearLayoutManager linearLayoutManager = (LinearLayoutManager) getRecyclerView().getLayoutManager();
                int n = nextPosition - linearLayoutManager.findFirstVisibleItemPosition();
                if (n >= 0 && n < getRecyclerView().getChildCount()) {
                    //獲取要置頂?shù)捻?xiàng)頂部距離RecyclerView頂部的距離
                    int top = getRecyclerView().getChildAt(n).getTop();
                    //進(jìn)行第二次滾動(dòng)（最后的距離）
                    getRecyclerView().smoothScrollBy(0, top);
                }
            }
        }

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

        }
    }