RecyclerView：带header&footer&加载更多

接上一篇
由简到繁，循序渐进
实现了：
0，点击&长按事件；
1，header；
2，footer；
3，加载更多；
4，还想下拉刷新？“想的美，这本就不是RecyclerView该做的事情！”

import java.util.ArrayList;import java.util.List;import com.example.test.R;import com.widget.view.HeaderFooterAdapter.ViewHolder;import android.support.v7.widget.RecyclerView;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;/** * 为了用RecyclerView创建一个带header的grid：1,定义一个具有两种view类型的adapter，一个为header一个为普通item。2,inflate一个header，把它传递给adapter。3,重写GridLayoutManager中的setSpanSizeLookup，在header所处的位置返回和span count（列数）相等的 span size。 * @author Administrator * */public class HeaderFooterAdapter<T> extends RecyclerView.Adapter<ViewHolder> {private static final int ITEM_VIEW_TYPE_HEADER = 0;private static final int ITEM_VIEW_TYPE_ITEM = 1;private static final int ITEM_VIEW_TYPE_FOOTER = 2;private final View header;private final View footer;private int headerCount=0;private int footerCount=0;private final List<T> beans;public HeaderFooterAdapter(View header, View footer,List<T> beans) {headerCount=header == null?0:1;footerCount=footer == null?0:1;this.header = header;this.footer = footer;this.beans = beans;}public boolean isHeader(int position) {if(headerCount==0){return false;}return position == 0;}public boolean isFooter(int position) {if(footerCount==0){return false;}return position == beans.size()+headerCount;// add 1 for footer//return position == getItemCount()-headerCount;// or Subtract 1 for footer}@Overridepublic ViewHolder<T> onCreateViewHolder(ViewGroup parent, int viewType) {if (viewType == ITEM_VIEW_TYPE_HEADER) {return new ViewHolder<T>(header);}if (viewType == ITEM_VIEW_TYPE_FOOTER) {return new ViewHolder<T>(footer);}View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);return new ViewHolder<T>(view);}@Overridepublic void onBindViewHolder(final ViewHolder holder, final int position) {if (isHeader(position)) {return;}if (isFooter(position)) {return;}final T bean = beans.get(position - headerCount); // Subtract 1 for headerholder.textView.setText(bean.toString());}@Overridepublic int getItemViewType(int position) {if(isHeader(position)){return ITEM_VIEW_TYPE_HEADER;}if(isFooter(position)){return ITEM_VIEW_TYPE_FOOTER;}return ITEM_VIEW_TYPE_ITEM;}/** * 获得实际View的数量，包括header和footer */@Overridepublic int getItemCount() {return beans.size() + headerCount+footerCount;}class ViewHolder<T> extends RecyclerView.ViewHolder implements View.OnClickListener,View.OnLongClickListener{public TextView textView;public ViewHolder(View itemView) {super(itemView);if (onItemClickLitener != null){itemView.setOnClickListener(this);            }if(onItemLongClickLitener!=null){itemView.setOnLongClickListener(this);            }textView = (TextView) itemView.findViewById(R.id.item_0);}@Overridepublic void onClick(View v) {// TODO Auto-generated method stubonItemClickLitener.onItemClick(v, getLayoutPosition());//getPosition()被废弃了}@Overridepublic boolean onLongClick(View v) {// TODO Auto-generated method stubonItemLongClickLitener.onItemLongClick(v, getLayoutPosition());return true;}}private static OnItemClickLitener onItemClickLitener;public void setOnItemClickLitener(OnItemClickLitener onItemClickLitener) {this.onItemClickLitener = onItemClickLitener;}public interface OnItemClickLitener {/** * 点击回调，注意position，指的是在Adapter中的位置，已经算上header * @param view * @param position */void onItemClick(View view, int position);}private static OnItemLongClickLitener onItemLongClickLitener;public void setOnItemLongClickLitener(OnItemLongClickLitener onItemLongClickLitener) {this.onItemLongClickLitener = onItemLongClickLitener;}public interface OnItemLongClickLitener {/** * 长按回调，注意position，指的是在Adapter中的位置，已经算上header * @param view * @param position */void onItemLongClick(View view, int position);}/** * 在position位置插入item * @param position:指的是item在beans中的位置，而不是在Adapter中的位置； * 所以在notifyItemInserted的时候需要算上header * @param item */public void addItemAt(int position,T item) {beans.add(position, item);        notifyItemInserted(position+headerCount);    }/** * 在底部添加Items * @param items */public void addItemsAtLast(ArrayList<T> items) {int size=beans.size();beans.addAll(items);notifyItemRangeInserted(size+headerCount, items.size());}/** * 移除position位置的Item * @param position :指的是item在beans中的位置，而不是在Adapter中的位置； * 所以在notifyItemInserted的时候需要算上header */public void removeItemAt(int position) {beans.remove(position);        notifyItemRemoved(position+headerCount);    }/** * 获得中间Item的数量，不包括header和footer * @return */public int getItemSize(){return beans.size();}}

ArrayList<String> list=new ArrayList<String>();    for (int i = 0; i < 30; ++i) {    list.add(String.valueOf(i));    }            View header = LayoutInflater.from(this).inflate(R.layout.header_view, recyclerView, false);        View footer = LayoutInflater.from(this).inflate(R.layout.footer_view, recyclerView, false);final HeaderFooterAdapter<String> adapter = new HeaderFooterAdapter<String>(header,footer, list);adapter.setOnItemClickLitener(new HeaderFooterAdapter.OnItemClickLitener() {@Overridepublic void onItemClick(View view, int position) {// TODO Auto-generated method stubif(adapter.isHeader(position)){Toast.makeText(context, "header clicked", Toast.LENGTH_SHORT).show();}else if(adapter.isFooter(position)){Toast.makeText(context, "footer clicked", Toast.LENGTH_SHORT).show();}else{Toast.makeText(context, "header item "+position, Toast.LENGTH_SHORT).show();}}});        final GridLayoutManager manager = new GridLayoutManager(this, 2);        manager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {@Overridepublic int getSpanSize(int position) {if(adapter.isHeader(position)||adapter.isFooter(position)){return manager.getSpanCount();}return  1;}});        //如果可以确定每个item的高度是固定的，设置这个选项可以提高性能        recyclerView.setHasFixedSize(true);        recyclerView.setLayoutManager(manager);recyclerView.setAdapter(adapter);recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {@Override public void onScrolled(RecyclerView rv, int dx, int dy) {                boolean isBottom =                manager.findLastCompletelyVisibleItemPosition()>= adapter.getItemCount()-1;                if (isBottom) {                ArrayList<String> list=new ArrayList<String>();                int size=adapter.getItemSize();            for (int i = size; i < 30+size; ++i) {            list.add(String.valueOf(i));            }                adapter.addItemsAtLast(list);                }            }});

这是一个如你熟悉ListView、GridView一样熟悉的RecyclerView类库，你可以用以前使用ListView / GridView的习惯来使用RecyclerView，这些可让你将项目原有的ListView / GridView / 瀑布流 迁移到RecyclerView时减少许多工作量.

你必须了解的RecyclerView的五大开源项目-解决上拉加载、下拉刷新和添加Header、Footer等问题
http://www.see-source.com/blog/300000035/1463.html

滑动到顶部/底部 可拉伸回弹的ListView与ScrollView
https://github.com/teisun/SunmiUI