listview 上拉加载更多

package com.example.listviewflash;

import java.util.ArrayList;
import java.util.List;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.ListFragment;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

/**
 * 
 * @author xiaoxi
 * @see comm
 * 
 */
public class MyListFragment extends ListFragment implements OnScrollListener {
	protected static final String TAG = "MyListFragment";
	private List<MyEntity> entitieList;// json数据集合
	private MyEntity myEntity;// json数据的entity
	private MyListFragmntAdapter adapter;// fragment的适配器
	private LinearLayout footView;// 加载画面时显示的布局控件
	private TextView tv_load;// footView的控件
	private ProgressBar pb_load;// footView的控件
	private int pageNo = 1;// 页数
	private TextView empty;// listview无数据显示的内容
	private ListView listView;//
	boolean isLoading = false;// 是否滑动的标志位
	String shuming = "";
	String bookid = "";
	private int totalPages;// 总页数
	private int totalRecord;// 总记录数
	private Handler handler = new Handler() {

		public void handleMessage(android.os.Message msg) {

			switch (msg.what) {
			case 10:
				// listview无数据时显示empty textview
				if (entitieList == null || entitieList.size() <= 0) {
					getListView().setVisibility(View.GONE);
					empty.setVisibility(View.VISIBLE);
					return;
				}
				listView.addFooterView(footView);
				Log.e(TAG, "====================第一次添加footview==");
				adapter = new MyListFragmntAdapter(getActivity(), entitieList);
				setListAdapter(adapter);
				// 此处一下为当数据不足一页时移除footview并吐司
				afterLoadingData();
				if (adapter.getCount() >= totalRecord) {
					Toast.makeText(getActivity(), "数据全部加载！", 0).show();
				}
				break;

			case 110:
				List<MyEntity> myanswerModels = new ArrayList<MyEntity>();
				myanswerModels = (List<MyEntity>) msg.obj;
				if (myanswerModels != null && myanswerModels.size() > 0) {
					adapter.addExtra(myanswerModels);
					afterLoadingData();
				}
				if (adapter.getCount() >= totalRecord) {
					Toast.makeText(getActivity(), "数据全部加载！", 0).show();
				}
				break;
			}
		};
	};

	@Override
	public void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
	}

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		View view = inflater.inflate(R.layout.fragmentlayout, null, false);
		// 系统的listview在此处直接findViewById，如果getListView()的话会报错
		// java.lang.IllegalStateException: Content view not yet
		// created(ListFragment)
		listView = (ListView) view.findViewById(android.R.id.list);
		empty = (TextView) view.findViewById(android.R.id.empty);
		footView = (LinearLayout) LayoutInflater.from(getActivity()).inflate(
				R.layout.listview_item, null, false);
		tv_load = (TextView) footView.findViewById(R.id.tv_load);
		pb_load = (ProgressBar) footView.findViewById(R.id.pb_load);
		// 页数在这里重新定义，因为当viewpager里的几个fragment滑动切换时fragment从回退站返回栈顶，fragment的周期是从
		// onDestroyView到onCreateView重新加载数据（否则会显示footview）
		pageNo = 1;
		listView.setOnScrollListener(this);

		new Thread(new Runnable() {

			@Override
			public void run() {
				// TODO Auto-generated method stub
				entitieList = getNetWorkData(pageNo, shuming, bookid);
				Message message = Message.obtain();
				message.what = 10;
				handler.sendMessage(message);
			}
		}).start();
		return view;
	}

	// 模拟下载网络数据
	public List<MyEntity> getNetWorkData(Integer page_no, String params1,
			String params2) {
		List<MyEntity> list = new ArrayList<MyEntity>();
		// 地址
		String url = "";
		// 其他参数
		String params = "";
		String json = HttpUtils.getDataByPost(url, params);
		try {
			JSONArray array = new JSONArray(json);
			for (int i = 0; i < array.length(); i++) {
				JSONObject jsonObject = array.getJSONObject(i);
				myEntity = MyEntity.parseMyEntityData(jsonObject);
				list.add(myEntity);
			}
		} catch (JSONException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return list;
	}

	public void afterLoadingData() {
		listView.removeFooterView(footView);
		isLoading = false;
	}

	@Override
	public void onPause() {
		// TODO Auto-generated method stub
		super.onPause();
	}

	@Override
	public void onScrollStateChanged(AbsListView view, int scrollState) {
		// TODO Auto-generated method stub

	}

	@Override
	public void onScroll(AbsListView view, int firstVisibleItem,
			int visibleItemCount, int totalItemCount) {
		// TODO Auto-generated method stub
		// 滑动加载数据
		int lastItem = listView.getLastVisiblePosition();
		// totalItem = totalItemCount;
		// Log.e(TAG, "====lastItem:tt====" + lastItem);
		if (lastItem + 1 >= totalItemCount) {
			if (pageNo < totalPages && !isLoading) {
				listView.removeFooterView(footView);
				listView.addFooterView(footView);
				Log.e(TAG, "====================第二次添加footview==");
				isLoading = true;
				pageNo++;
				new Thread(new Runnable() {

					@Override
					public void run() {
						// TODO Auto-generated method stub
						List<MyEntity> myanswerModels = new ArrayList<MyEntity>();
						myanswerModels = getNetWorkData(pageNo, shuming, bookid);
						Message message = Message.obtain();
						message.what = 110;
						message.obj = myanswerModels;
						handler.sendMessage(message);

					}
				}).start();
			}
		}
	}
}

本例子 在listview上拉时并执行viewpager里多个fragment切换 操作 可能会报
cannot be cast to android.widget.HeaderViewListAdapter
希望大神指教。。