之前自己嘗試用ViewType的思路去實現為RecyclerView新增HeadView和FootView，總感覺自己寫的程式碼太囉嗦了，向兩位大神學習了一下他們的編碼思路寫了個簡單了些的，分享給大家。

廢話不多說，上圖上程式碼。

public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> {

    private View headView;
    private View footView;
    public static final int HEAD = 1;
    public static final int NORMAL = 2;
    public static final int FOOT = 3;

    private List<String> datas;

    public RecyclerAdapter(List<String> datas) {
        this.datas = datas;
    }

    public void addHeadView(View headView) {
        this.headView = headView;
    }

    public void addFootView(View footView) {
        this.footView = footView;
    }

    public int getHeadViewCount() {
        return headView == null ? 0 : 1;
    }

    public int getFootViewCount() {
        return footView == null ? 0 : 1;
    }

    @Override
    public int getItemCount() {
        return datas.size() + getHeadViewCount() + getFootViewCount();
    }

    @Override
    public int getItemViewType(int position) {
        if (position < getHeadViewCount()) return HEAD;
        if (position >= datas.size() + getHeadViewCount()) return FOOT;
        return NORMAL;
    }


    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
        if (viewType == HEAD) return new ViewHolder(headView);
        if (viewType == FOOT) return new ViewHolder(footView);
        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.layout_recycleritem, null);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        if (getItemViewType(position) == HEAD) return;
        if (getItemViewType(position) == FOOT) return;
        holder.tvItem.setText(datas.get(position-getHeadViewCount()));
    }

    class ViewHolder extends RecyclerView.ViewHolder {
        @BindView(R.id.tv_item)
        TextView tvItem;
        public ViewHolder(View itemView) {
            super(itemView);
            if (itemView == headView) return;
            if (itemView == footView) return;
            ButterKnife.bind(this, itemView);
        }
    }
}