RecyclerView 上拉加载更多

Recyclerview 是谷歌官方推荐的新的列表控件，网上关于recyclerview的用法也颇有深度，她有自带的SwipeRefreshLayout 可很好的提供下拉刷新，唯独没有上拉加载控件，
需要使用的一般都采用其他的方法，这里，有一篇关于RecyclerView的上拉加载的文章，
直接上代码：
/**

• Created by Kevin_zhou on 2016/11/11.
  */
  public class TulingAdapter extends RecyclerView.Adapter {

  private static final int TYPE_ZIJI_ITEM = 0; //普通Item
  private static final int TYPE_FOOTER_ITEM = 1; //底部FooterView
  private static final int TYPE_TULING = 2;

  //上拉加载更多
  public static final int PULLUP_LOAD_MORE = 1;
  //正在加载中
  public static final int LOADING_MORE = 2;
  //默认为0
  private int load_more_status = 1;

  public List list;
  private OnItemClickListener mClickListener;

  public void setData(List list){
  this.list = list;
  }

  //创建新View，被LayoutManager所调用
  @Override
  public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
  //如果viewType是普通item返回普通的布局，否则是底部布局并返回
  if (viewType == TYPE_ZIJI_ITEM) {
  View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout
  .cardview_recyclerview_item, viewGroup, false);
  final ZiJiViewHolder vh = new ZiJiViewHolder(view);
  if (mClickListener != null) {
  vh.itemView.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View view) {
  mClickListener.onItemClick(vh.itemView, vh.getLayoutPosition());
  }
  });
  }
  return vh;
  } else if (viewType == TYPE_TULING) {
  View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.char_tuling, viewGroup, false);
  final TuLingViewHolder holder = new TuLingViewHolder(view);
  if (mClickListener != null) {
  holder.itemView.setOnClickListener(new View.OnClickListener() {

               @Override
               public void onClick(View view) {
                   mClickListener.onItemClick(holder.itemView, holder.getLayoutPosition());
               }
           });
       }
       return holder;
   } else {
       View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout
               .recyclerview_footer_view, viewGroup, false);
       FooterViewHolder vh = new FooterViewHolder(view);
       return vh;
   }
  

  }

  //将数据与界面进行绑定的操作
  @Override
  public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) {
  if (viewHolder instanceof ZiJiViewHolder) {
  ((ZiJiViewHolder) viewHolder).contentTv.setText(list.get(position).getContent());
  } else if (viewHolder instanceof TuLingViewHolder){
  ((TuLingViewHolder) viewHolder).contentTv.setText(list.get(position).getContent());
  }
  else if (viewHolder instanceof FooterViewHolder) {
  FooterViewHolder footViewHolder = (FooterViewHolder) viewHolder;
  switch (load_more_status) {
  case PULLUP_LOAD_MORE:
  footViewHolder.foot_view_item_tv.setVisibility(View.VISIBLE);
  footViewHolder.foot_view_item_tv.setText("上拉加载更多");
  footViewHolder.pb.setVisibility(View.GONE);
  break;
  case LOADING_MORE:
  footViewHolder.foot_view_item_tv.setVisibility(View.GONE);
  footViewHolder.pb.setVisibility(View.VISIBLE);
  break;
  }
  }
  }

  @Override
  public int getItemCount() {
  //+1是加入底部的加载布局项
  return list.size() + 1;
  }

  public int getItemViewType(int position) {
  // 如果position+1等于整个布局所有数总和就是底部布局
  if (position + 1 == getItemCount()) {
  return TYPE_FOOTER_ITEM;
  } else {
  if (list.get(position).getType() == 1){
  return TYPE_TULING;
  }else {
  return TYPE_ZIJI_ITEM;
  }
  }
  }

  //自定义的ViewHolder，持有每个Item的的所有界面元素
  public static class ZiJiViewHolder extends RecyclerView.ViewHolder {
  public TextView contentTv;
  public ImageView iv;

   public ZiJiViewHolder(View view) {
       super(view);
       contentTv = (TextView) view.findViewById(R.id.tv_chat_me);
       iv = (ImageView) view.findViewById(R.id.iv_chat_me);
   }
  

  }

  //图灵布局
  public static class TuLingViewHolder extends RecyclerView.ViewHolder {
  public TextView contentTv;
  public ImageView iv;

   public TuLingViewHolder(View view) {
       super(view);
       contentTv = (TextView) view.findViewById(R.id.tv_chat_tu);
       iv = (ImageView) view.findViewById(R.id.iv_chat_tu);
   }
  

  }

  /**

  • 底部FooterView布局
    */
    public static class FooterViewHolder extends RecyclerView.ViewHolder {
    public TextView foot_view_item_tv;
    public ProgressBar pb;

    public FooterViewHolder(View view) {
    super(view);
    pb = (ProgressBar) view.findViewById(R.id.progress_view);
    foot_view_item_tv = (TextView) view.findViewById(R.id.tv_content);
    }
    }

  public void setMoreStatus(int status){
  load_more_status=status;
  notifyDataSetChanged();
  }

  public void setOnItemClickListener(OnItemClickListener listener) {
  mClickListener = listener;
  }

public interface OnItemClickListener {
    public void onItemClick(View itemView, int pos);
}

}

上面是RecyclerView适配器，就是对RecyclerView滚动监听，请看下面如何使用

mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
private int lastVisibleItem;

        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            super.onScrollStateChanged(recyclerView, newState);
            if (!swipeRefreshWidget.isRefreshing()) {
                if (newState == RecyclerView.SCROLL_STATE_IDLE && lastVisibleItem + 1 ==
                        adapter.getItemCount()) {
                    swipeRefreshWidget.setEnabled(false);
                    adapter.setMoreStatus(PullMoreRecyclerAdapter.LOADING_MORE);
                    new Handler().postDelayed(new Runnable() {
                        @Override
                        public void run() {
                            getDatas();
                            swipeRefreshWidget.setEnabled(true);
                            adapter.setMoreStatus(PullMoreRecyclerAdapter.PULLUP_LOAD_MORE);
                            adapter.notifyDataSetChanged();
                        }
                    }, 3000);
                }
            }
        }

        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            super.onScrolled(recyclerView, dx, dy);
            lastVisibleItem = mLayoutManager.findLastVisibleItemPosition();
        }
    });

如有疑问，欢迎提出。