Android深入浅出学习笔记之多线程及异步处理(3)

        } 
 
        //在PreExcute执行后被启动AysncTask的后台线程调用，将结果返回给UI线程 
        @Override 
        protected String doInBackground(String... params) { 
            // TODO Auto-generated method stub 
            StringBuffer sb=new StringBuffer(); 
            for (String string : params) { 
                sb.append(string); 
            } 
            return sb.toString(); 
        } 
         
    } 
    //用于线程间通信的Handler 
    class TestHandler extends Handler 
    { 
         
        public TestHandler(Looper looper) { 
            super(looper); 
            // TODO Auto-generated constructor stub 
        } 
 
        @Override 
        public void handleMessage(Message msg) { 
            // TODO Auto-generated method stub 
            System.out.println("123"); 
            txView.setText((String)msg.getData().get("tag")); 
            super.handleMessage(msg); 
        } 
         
    } 
    //后台线程类 
    class TestThread extends Thread 
    { 
        Activity activity; 
        public TestThread(Activity activity) { 
             
            this.activity = activity;