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);