将网络访问放到另一个线程之后还是出现android.os.NetworkOnMainThreadException错误

   @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
       // requestWindowFeature(Window.FEATURE_NO_TITLE);   
        setContentView(R.layout.activity_main);
        setActionBarLayout( R.layout.nav_title );

     new Thread(downloadRun).run();  // Create a connect.  
    }
Runnable downloadRun = new Runnable(){  

   @Override  
    public void run() {  
       // TODO Auto-generated method stub  
	   String url = "http://www.ccc.com/phone/data.php";
 	  getPDAServerData(url);
   }  
      };  

    	
    	private void getPDAServerData(String url) {  
    	    HttpClient client = new DefaultHttpClient();  
    	    //提拱默认的HttpClient实现  
    	    HttpPost request;  
    	    try {  
    	        request = new HttpPost(new URI(url));  
    	        HttpResponse response = client.execute(request);  
    	        // 判断请求是否成功  
    	        if (response.getStatusLine().getStatusCode() == 200) { //200表示请求成功  
    	            HttpEntity entity = response.getEntity();  
    	            if (entity != null) {  
    	                String out = EntityUtils.toString(entity, "UTF-8");  
    	                Log.i(TAG, out);
    	                
    	                JSONArray jsonArray = new JSONArray(out);
    	                
    	                videos = new ArrayList<HashMap<String, Object>>();
    	                for(int i = 0; i<jsonArray.length(); i++) {
    	                	JSONObject jsonObject = (JSONObject) jsonArray.get(i);
    	                	int id = jsonObject.getInt("id");
    	                	String name = jsonObject.getString("name");
    	                	String timelength = jsonObject.getString("Fbirthday");
    	                	String nongli = jsonObject.getString("nongli");
    	                	String haiyou = jsonObject.getString("haiyou");
    	                
    	                	video = new HashMap<String, Object>();
    	             	if(nongli.trim().equals("农历"))
    	             	{
    	             		video.put("ItemImage", R.drawable.lunar_icon);//图像资源的ID
    	             	}
    	             	else