核心控制
linearLayoutManager.scrollToPositionWithOffset(0, 0);
linearLayoutManager = new LinearLayoutManager(this,LinearLayoutManager.HORIZONTAL,false);
// linearLayoutManager.setOrientation(linearLayoutManager.HORIZONTAL);
// linearLayoutManager.scrollToPositionWithOffset(0, 0);
mRecyclerView.setLayoutManager(linearLayoutManager);
homeAdapter = new HomeAdapter(RecyclerViewActivity.this, mDatas);
mRecyclerView.setAdapter(homeAdapter);
linearLayoutManager.scrollToPositionWithOffset(0, 0);