纵向的ListView或RecyclerView点击都可以让item跳到中间(类似TabLayout的滑动)

这里使用的是RecyclerView不是listview,原理一样

recyclerview.setOnItemClickListener(new FM_FenLei_LeftAdapter.OnItemClickListener() {

    private int childCount = 0;
    private int middlechild = 0;

    @Override
    public void ItemClick(View view, int position) {
       
        //得到布局
        RecyclerView.LayoutManager manager = left_recyclerView.getLayoutManager();
        //竖排类型,所以强转LinearLayoutManager,如果是ListView就不需要强转
        LinearLayoutManager layoutManager = (LinearLayoutManager) manager;

        //得到屏幕可见的item的总数
        childCount = layoutManager.getChildCount();
        if (childCount != left_list.size()) {
            //可见item的总数除以2  就可以拿到中间位置
            middlechild = childCount / 2;
        }

        //判断你点的是中间位置的上面还是中间的下面位置
        //RecyclerView必须加 && position != 2,listview不需要
        if (position <= (layoutManager.findFirstVisibleItemPosition() + middlechild) && position != 2) {
            left_recyclerView.smoothScrollToPosition(position + 1 - middlechild);
        } else {
            left_recyclerView.smoothScrollToPosition(position - 1 + middlechild);
        }
    }
});