数日前にこれに似た質問をしましたが、今問題に遭遇しました。以下では、asynctaskWeb サービス データを解析しています。私のWebサービスがこのデータを私のjson文字列に返すとき
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): }, {
私はそれを解析して表示しますが、これをjson文字列に返すと
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): }
私のコードは、エラー メッセージを表示してから、ユーザーをメイン アクティビティに戻すことを想定していました。それが返されたときcount 0、アプリケーションは何もしません。つまり、doInBackgroundメソッドが完了すると、Web サービスがデータを返していないため、空白の画面が表示されるだけです。私が支援されたコードが存在しないように振る舞います。ですから、誰かがこれについて私を助けてくれることを望んでいました.
protected String doInBackground(String... args) {
try {
if (Integer.parseInt(json.getJSONObject("all").getString("count"))<=0){return "0";
}else{
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 TAG_QUESTION ;
}
@Override
protected void onPostExecute(String file_URL) {
if(TAG_COUNT == null || TAG_COUNT.equals("0")){
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);
}}}