EasyRecyclerView添加header,默认隐藏header，easyrecyclerview.scrollToPosition(0)了也不起作用，麻烦指导下

[SiberiaDante]

    mRecyclerView = (EasyRecyclerView) findViewById(R.id.recycler_view_focus_main);
    mRecyclerView.setAdapter(adapter = new FocusFragmentMainAdapter(getActivity()));
    mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
    mRecyclerView.setRefreshListener(this);
    adapter.addHeader(new RecyclerArrayAdapter.ItemView() {
        @Override
        public View onCreateView(ViewGroup parent) {
            final View header = LayoutInflater.from(parent.getContext()).inflate(R.layout.header_focus_main, null, false);
            viewById = ((TextView) header.findViewById(R.id.tv_hedaer_content));
            viewById.setText("头布局头布局");
            return header;
        }

        @Override
        public void onBindView(View headerView) {
        }
    });
    adapter.addAll(mDatas);
    mRecyclerView.scrollToPosition(0);