ListView数据的分批加载

public class MainActivity extends Activity {
     private ListView listView;
     private List<String> data = new ArrayList<String>();
     ArrayAdapter<String> adapter;
     View footer;
     
     @Override
     public void onCreate(Bundle savedInstanceState) {
 
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         
         footer = getLayoutInflater().inflate(R.layout.footer, null);
         
         listView = (ListView) this.findViewById(R.id.listView);
         listView.setOnScrollListener(new ScrollListener());
         
         data.addAll(DataService.getData(0, 20));        
         adapter = new ArrayAdapter<String>(this, R.layout.listview_item, R.id.textView, data);
         listView.addFooterView(footer);//添加页脚(放在ListView最后)
         listView.setAdapter(adapter);
         listView.removeFooterView(footer);
     }
     
     private int number = 20;//每次获取多少条数据
     private int maxpage = 5;//总共有多少页
     private boolean loadfinish = true;
 
     private final class ScrollListener implements OnScrollListener{
 
         public void onScrollStateChanged(AbsListView view, int scrollState) {
             Log.i("MainActivity", "onScrollStateChanged(scrollState="+ scrollState+ ")");
         }
         
         public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
             Log.i("MainActivity", "onScroll(firstVisibleItem="+ firstVisibleItem+ ",visibleItemCount="+
                     visibleItemCount+ ",totalItemCount="+ totalItemCount+ ")");
             
             final int loadtotal = totalItemCount;
             int lastItemid = listView.getLastVisiblePosition();//获取当前屏幕最后Item的ID
             
             if((lastItemid+1) == totalItemCount){//达到数据的最后一条记录
                 if(totalItemCount > 0){
                     //当前页
                     int currentpage = totalItemCount%number == 0 ? totalItemCount/number : totalItemCount/number +1;
                     int nextpage = currentpage + 1;//下一页
                     if(nextpage <= maxpage && loadfinish){
                         loadfinish = false;
                         listView.addFooterView(footer);
                         
                         new Thread(new Runnable() {                        
                             public void run() {
                                 try {
                                     Thread.sleep(3000);
                                 } catch (InterruptedException e) {
                                     e.printStackTrace();
                                 }
                                 List<String> result = DataService.getData(loadtotal, number);
                                 handler.sendMessage(handler.obtainMessage(100, result));
                             }
                         }).start();
                     }        
                 }
                         
             }
         }
     }
     
     Handler handler = new Handler(){
         public void handleMessage(Message msg) {
             data.addAll((List<String>) msg.obj);
             adapter.notifyDataSetChanged();//告诉ListView数据已经发生改变，要求ListView更新界面显示
             if(listView.getFooterViewsCount() > 0) listView.removeFooterView(footer);
             loadfinish = true;
         }        
     };
     
 }

public class DataService {
 
     public static List<String> getData(int offset, int maxResult){//分页 limit 0,20
         List<String> data = new ArrayList<String>();
         for(int i=0 ; i < 20 ; i++){
             data.add("ListView数据的分批加载"+ i);
         }
         return data;
     }
 }