onPostExecute不执行我的方法

Question

在我的应用程序中，我的onPostExecute执行某种方法，如果我的Web服务没有返回任何数据。在我的一个老问题中，我遇到过这样的问题，您可以在这里看到onPostExecute causing application to crash现在，如果您在该链接中阅读我的问题，那么您会知道，当我的应用程序返回值"0"时，它会崩溃。但现在我的问题是不同的，每当我的Web服务确实返回计数"0"我的应用程序显示一个空白布局，而不是执行我希望它执行的方法。有人可以在我的onPostExecute长时间，并帮助我解决这个问题。

   final String TAG_RESULTS = "results"; 
final String TAG_QUESTION_SUBJECT = "Subject"; 
final String TAG_QUESTION_NUMANSWERS = "NumAnswers"; 
final String TAG_QUESTION = "question"; 
final String TAG_QUESTION_CONTENT = "Content"; 
final String TAG_QUESTION_CHOSENANSWER = "ChosenAnswer"; 
final String TAG_ANSWERS = "Answers"; 
final String TAG_ANSWER = "Answer";  
final String TAG_ANSWERS_CONTENT = "content";  
final String TAG_QUERY = "query"; 
final String TAG_COUNT = "count"; 
ProgressDialog pDialog; 
LoadAllData mTask; 

....

保护字符串doInBackground（字符串参数... args）{

  pDialog.setOnCancelListener(new DialogInterface.OnCancelListener(){ 
       public void onCancel(DialogInterface dialog) { 
        mTask.cancel(true); 
        finish(); 
      } 
     }); 

      try { 
       Intent in = getIntent(); 
       String searchTerm = in.getStringExtra("TAG_SEARCH"); 
       String query = URLEncoder.encode(searchTerm, "utf-8"); 
       String URL = "http://example.com"; 
       JSONParsser jParser = new JSONParsser(); 
       JSONObject json = jParser.readJSONFeed(URL); 
       try { 

        JSONArray questions = json.getJSONObject("all").getJSONArray("questions"); 

        for(int i = 0; i < questions.length(); i++) { 
         JSONObject question = questions.getJSONObject(i); 


        String Subject = question.getString(TAG_QUESTION_SUBJECT); 
        String ChosenAnswer = question.getString(TAG_QUESTION_CHOSENANSWER); 
        String Content = question.getString(TAG_QUESTION_CONTENT); 

          HashMap<String, String> map = new HashMap<String, String>(); 

          map.put(TAG_QUESTION_SUBJECT, Subject); 
          map.put(TAG_QUESTION_CONTENT, Content); 
          map.put(TAG_QUESTION_CHOSENANSWER, ChosenAnswer); 

          questionList.add(map); 

       } 


       } catch (JSONException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
     } catch (UnsupportedEncodingException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 

       return null;  

    } 



@Override 
    protected void onPostExecute(String file_URL) { 

     if(file_URL!=null && file_URL.equals("0")) { 
      pDialog.dismiss(); 
      Toast.makeText(ListView.this, "No data found", Toast.LENGTH_SHORT).show(); 
      finish(); 

     } else { 

      if (pDialog != null && pDialog.isShowing()) 
       pDialog.dismiss(); 
      ListAdapter adapter = new SimpleAdapter(getBaseContext(), questionList, 
        R.layout.listelements, 
        new String[] { TAG_QUESTION_SUBJECT }, new int[] { 
        R.id.Subject,}); 

      setListAdapter(adapter);     

     } 
    } 

这就是数据看起来，当它返回count "0"

09-02 00:25:55.466: D/JSON String(882): { 
09-02 00:25:55.466: D/JSON String(882): "all" : { 
09-02 00:25:55.466: D/JSON String(882):  "count" : 0, 
09-02 00:25:55.466: D/JSON String(882):  "questions" : [  ] 
09-02 00:25:55.466: D/JSON String(882):  } 
09-02 00:25:55.466: D/JSON String(882): } 

像

数据看起来像什么时它返回数据或有效count

08-30 00:36:07.917: D/JSON String(1891): { 
08-30 00:36:07.917: D/JSON String(1891): "all" : { 
08-30 00:36:07.917: D/JSON String(1891): "count" : 25, 
08-30 00:36:07.917: D/JSON String(1891): "questions" : [  { 
08-30 00:36:07.917: D/JSON String(1891):   "Id" : "20100728112033AAb4hTA", 
08-30 00:36:07.917: D/JSON String(1891):   "Subject" : "What is the oldest a bitch can more or less safely breed?", 
08-30 00:36:07.917: D/JSON String(1891):   "Content" : "Don't worry I'm not going to breed - both my bitches are getting neutered in the next year, as is my dog! Just that me and a friend were talking about it after talking to the man who gave me Misty (my border collie) who said she could still breed at 7 - I thought the oldest was 5?\n", 
08-30 00:36:07.917: D/JSON String(1891):   "Date" : "2010-07-28 18:20:33", 
08-30 00:36:07.917: D/JSON String(1891):   "Timestamp" : "1280341233", 
08-30 00:36:07.917: D/JSON String(1891):   "Link" : "http://answers.yahoo.com/question/?qid=20100728112033AAb4hTA", 
08-30 00:36:07.917: D/JSON String(1891):   "Type" : "Answered", 
08-30 00:36:07.917: D/JSON String(1891):   "CategoryId" : 396546021, 
08-30 00:36:07.917: D/JSON String(1891):   "CategoryName" : "Dogs", 
08-30 00:36:07.917: D/JSON String(1891):   "UserId" : "cP16Ctgxaa", 
08-30 00:36:07.917: D/JSON String(1891):   "UserNick" : "Kiko", 
08-30 00:36:07.917: D/JSON String(1891):   "UserPhotoURL" : "http://l.yimg.com/dg/users/1t1USxJpxAAEBQOGZjBMW0-5Wp_EG.medium.jpg", 
08-30 00:36:07.917: D/JSON String(1891):   "NumAnswers" : 8, 
08-30 00:36:07.917: D/JSON String(1891):   "NumComments" : 0, 
08-30 00:36:07.917: D/JSON String(1891):   "ChosenAnswer" : "You just \"imagined\" that ,dear...not \"thought\". & your imagination is WRONG.\r\n\r\n9 or even 10,for a healthy TOP-PRODUCING bitc-h.\r\n\r\n\r\n\r\n*&* bitches are SPAYED & dogs are CASTRATED......big scary correct ADULT words.", 
08-30 00:36:07.917: D/JSON String(1891):   "ChosenAnswererId" : "clN6YITvaa", 
08-30 00:36:07.917: D/JSON String(1891):   "ChosenAnswererNick" : "Debunker", 
08-30 00:36:07.917: D/JSON String(1891):   "ChosenAnswerTimestamp" : "1280317077", 
08-30 00:36:07.917: D/JSON String(1891):   "ChosenAnswerAwardTimestamp" : "1280835336" 
08-30 00:36:07.917: D/JSON String(1891):  },  { 

为什么屏幕是空白的，因为它试图填充我的列表视图，但计数为零，所以这就是为什么它是空白的。我只需要知道为什么它不会执行if(file_URL!=null && file_URL.equals("0")) { pDialog.dismiss(); Toast.makeText(ListView.this, "No data found", Toast.LENGTH_SHORT).show(); finish();当它返回count "0"

Answer 1

每当我的web服务不会返回数“0”我的应用程序显示一个空白的布局，而不是执行我想它要执行的方法。

如果返回0然后将运行的唯一代码

pDialog.dismiss(); 
    Toast.makeText(ListView.this, "No data found", Toast.LENGTH_SHORT).show(); 
    finish(); 

从我所看到的，你是不是调用一个方法以外解雇你ProgressDialog，呈现出Toast，再整理您的Activity。