Android开发中利用ListView怎么实现一个分页加载功能

package eoe.listview;
import android.app.Activity;
import android.database.Cursor;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.AdapterView.OnItemSelectedListener;
public class MainActivity extends Activity {
  private ListView listview;
  private ProgressBar loadBar;
  private TextView loadText;
  private ShopAdapter adapter;
  private int start=0; //开始数量
  private int limit=3; //每页数量
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    listview=(ListView)findViewById(R.id.main_ListView);
    loadBar=(ProgressBar)findViewById(R.id.main_loadBar);
    loadText=(TextView)findViewById(R.id.main_loadText);
    adapter=new ShopAdapter(this);
    listview.setAdapter(adapter);
    listview.setOnItemSelectedListener(new OnItemSelectedListener(){
      @Override
      public void onItemSelected(AdapterView arg0, View arg1,
      int count, long arg3) {
        if(adapter.getCount()==count+1){
          loadText.setText("下载中...");
          loadBar.setVisibility(View.VISIBLE);
          new Thread(mRunnable).start();
        }
      }
      @Override
      public void onNothingSelected(AdapterView arg0) {
      }
    });
    new Thread(mRunnable).start();
  }
  /**
  * 商店列表线程
  */
  private Runnable mRunnable=new Runnable(){
    public void run(){
      try {
        Thread.sleep(1500);
        mHandler.sendMessage(mHandler.obtainMessage());
      }
      catch (InterruptedException e) {
        //System.out.println("Error-"+e.getMessage());
      }
    }
  };
  Handler mHandler=new Handler(){
    public void handleMessage(Message msg){
      super.handleMessage(msg);
      loadHotShop(limit);
    }
  };
  /**
  * 加载店铺
  * @return
  */
  public void loadHotShop(int limit){
    DBLocalService db=new DBLocalService(this);
    Cursor cursor=db.querySQL("select * from "+db.TABLE_SHOP+" limit "+start+","+limit,null);
    if(cursor.getCount()>0) this.start+=limit;
    while(cursor.moveToNext()){
      Shop s=new Shop();
      s.setId(cursor.getString(cursor.getColumnIndex("id")));
      s.setTitle(cursor.getString(cursor.getColumnIndex("title")));
      adapter.addShop(s);
    }
    loadText.setText("");
    loadBar.setVisibility(View.GONE);
  }
}