Android recyclerView 滚动到指定位置 刚好滚动到 和滚动到顶部

滚动到顶部 

           val layoutManager = mBinding.rvList.layoutManager as LinearLayoutManager
                    mBinding.rvList.postDelayed({
                        layoutManager.scrollToPositionWithOffset(index, 0)
                    }, 20)

滚动到刚好的位置

     mBinding.rvList.postDelayed({  mBinding.rvList.scrollToPosition(index)  }, 20)