有时候我们需要修改已经生成的列表，添加或者修改数据，notifyDataSetChanged()可以在修改适配器绑定的数组后，不用重新刷新Activity，通知Activity更新ListView。今天的例子就是通过Handler AsyncTask两种方式来动态更新ListView.

布局main.xml:

 

1 
       2 
      
        7 
       12 
      

ListView列表布局playlist.xml:

 

1 
      2 
      

程序代码：

1 import java.util.ArrayList; 2   3  import android.app.Activity; 4  import android.os.AsyncTask; 5  import android.os.Bundle; 6  import android.os.Handler; 7  import android.view.View; 8  import android.widget.AdapterView; 9 import android.widget.ArrayAdapter;10 import android.widget.ListView;11 import android.widget.AdapterView.OnItemClickListener;12  13 public class main extends Activity {14     /** Called when the activity is first created. */15     ListView lv;16     ArrayAdapter
      
        Adapter;17     ArrayList
       
         arr=new ArrayList
        
         ();18     @Override19     public void onCreate(Bundle savedInstanceState) {20         super.onCreate(savedInstanceState);21         setContentView(R.layout.main);22         lv=(ListView)findViewById(R.id.lv);23         arr.add("123");24         arr.add("234");25         arr.add("345");26         Adapter = new ArrayAdapter
         
          (this,R.layout.playlist, arr);27         lv.setAdapter(Adapter);28         lv.setOnItemClickListener(lvLis); 29         editItem edit= new editItem();30         edit.execute("0","第1项");//把第一项内容改为"第一项"31         Handler handler=new Handler();32         handler.postDelayed(add,3000);//延迟3秒执行33     }34     Runnable add=new Runnable(){35  36         @Override37         public void run() {38             // TODO Auto-generated method stub39             arr.add("增加一项");//增加一项40             Adapter.notifyDataSetChanged();    41         }       42     };43     class editItem extends AsyncTask
          
           {44         @Override45         protected String doInBackground(String... params) {46                 arr.set(Integer.parseInt(params[0]),params[1]);47                 //params得到的是一个数组，params[0]在这里是"0",params[1]是"第1项"48                 //Adapter.notifyDataSetChanged();49                 //执行添加后不能调用 Adapter.notifyDataSetChanged()更新UI，因为与UI不是同线程50                 //下面的onPostExecute方法会在doBackground执行后由UI线程调用51             return null;    52         }53  54         @Override55         protected void onPostExecute(String result) {56             // TODO Auto-generated method stub57             super.onPostExecute(result);58             Adapter.notifyDataSetChanged();59             //执行完毕，更新UI60         }61  62     }63     private OnItemClickListener lvLis=new OnItemClickListener(){64         @Override65         public void onItemClick(AdapterView
            arg0, View arg1, int arg2,66                 long arg3) {67             //点击条目时触发68             //arg2即为点中项的位置69             setTitle(String.valueOf(arr.get(arg2)));70  71         }72  73     };74  75 }