從Assets文件夾解析JSON後，ListView中沒有加載值

我試圖從assets文件夾中的json文件中獲取值並將其加載到我的簡單列表視圖中。代碼中沒有錯誤，我嘗試記錄所有狀態。我可以在日誌貓中看到所需的值，但是當我使用適配器時，屏幕會加載但我看不到數據。從Assets文件夾解析JSON後，ListView中沒有加載值

我也在這個測試應用程序中使用片段，我總共有4個選項卡。在一個標籤中，我想顯示從json文件加載的所有數據。

我的適配器有問題嗎？一些幫助將會真正被貶低。

public class Test extends Fragment { 

    Context context; 

    // TextView tview; 
    ImageView iv; 
    ImageView iv1; 
    private static final String STATE = "state"; 

    ArrayList<HashMap<String, String>> jsonlist = new ArrayList<HashMap<String, String>>(); 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
     Bundle savedInstanceState) { 

     context = getActivity(); 

     View rootView = inflater.inflate(R.layout.xyz, container, false); 

     ListView lv1 = (ListView) rootView.findViewById(R.id.list); 
     TextView tv1 = (TextView) rootView.findViewById(R.id.rowidtext); 

     lv1.setAdapter(new SimpleAdapter(getActivity(), jsonlist, R.layout.xyz, 
      new String[] { STATE }, new int[] { R.id.rowidtext })); 

     try { 

      JSONObject json = new JSONObject(loadJSONFromAsset()); 

      if (json != null) { 

       JSONArray array = json.getJSONArray("Information"); 
       Log.i("Data1234", array.toString()); 

       for (int i = 0; i <= array.length(); i++) { 

        JSONObject c = array.getJSONObject(i); 

        String vstate = c.getString(STATE); 

        Log.i("STATE", vstate); 

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

        // Add child node to HashMap key & value 
        map.put(STATE, vstate); 

        jsonlist.add(map); 

       } 
       Log.i("Data Coming? ", jsonlist.toString()); 

      } 

     } catch (JSONException e) { 
      e.printStackTrace(); 
     } 
     Log.i("Data Coming? ", jsonlist.toString()); 
     return rootView; 
    } 

    public String loadJSONFromAsset() { 

     String json = null; 

     try { 

      InputStream is = getActivity().getAssets().open("testjson1.json"); 

      int size = is.available(); 

      byte[] buffer = new byte[size]; 

      is.read(buffer); 

      is.close(); 

      json = new String(buffer, "UTF-8"); 

     } catch (IOException ex) { 

      ex.printStackTrace(); 

      return null; 
     } 
     return json; 

    } 

}

的logcat：

10-28 22:43:08.364: D/dalvikvm(5806): GC_FOR_ALLOC freed 60K, 8% free 2779K/3016K, paused 23ms, total 25ms 
10-28 22:43:08.364: I/dalvikvm-heap(5806): Grow heap (frag case) to 3.957MB for 1127536-byte allocation 
10-28 22:43:08.474: D/dalvikvm(5806): GC_FOR_ALLOC freed 2K, 6% free 3878K/4120K, paused 100ms, total 100ms 
10-28 22:43:08.804: D/gralloc_goldfish(5806): Emulator without GPU emulation detected. 
10-28 22:43:13.845: I/Data1234(5806): [{"state":"JAVA","outdoorfun":"yes","additionalinfo":"{ search: 'online', website: 'http:\/\/states.arkansas.com', latitudeandlongitude: '93905, 63550}","cold":"no","type":"landlocked"},{"state":"ANDROID","outdoorfun":"no","additionalinfo":"{ search: 'online', website: 'http:\/\/states.chicago.com', latitudeandlongitude: '23905, 45355}","cold":"yes","type":"windy"},{"state":"CORE JAVA","outdoorfun":"no","additionalinfo":"{ search: 'online', website: 'http:\/\/states.chicago.com', latitudeandlongitude: '23905, 45355}","cold":"yes","type":"windy"},null] 
10-28 22:43:13.845: I/STATE(5806): JAVA 
10-28 22:43:13.845: I/STATE(5806): ANDROID 
10-28 22:43:13.845: I/STATE(5806): CORE JAVA 
10-28 22:43:13.855: W/System.err(5806): ***org.json.JSONException: Value at 3 is null.*** 
10-28 22:43:13.855: W/System.err(5806):  at org.json.JSONArray.get(JSONArray.java:259) 
10-28 22:43:13.855: W/System.err(5806):  at org.json.JSONArray.getJSONObject(JSONArray.java:480) 
10-28 22:43:13.855: W/System.err(5806):  at com.mike.myapp.Train.onCreateView(Train.java:91) 
10-28 22:43:13.855: W/System.err(5806):  at android.support.v4.app.Fragment.performCreateView(Fragment.java:1478) 
10-28 22:43:13.865: W/System.err(5806):  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:927) 
10-28 22:43:13.865: W/System.err(5806):  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104) 
10-28 22:43:13.865: W/System.err(5806):  at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682) 
10-28 22:43:13.865: W/System.err(5806):  at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1460) 
10-28 22:43:13.865: W/System.err(5806):  at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:472) 
10-28 22:43:13.865: W/System.err(5806):  at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141) 
10-28 22:43:13.865: W/System.err(5806):  at android.support.v4.view.ViewPager.populate(ViewPager.java:1068) 
10-28 22:43:13.875: W/System.err(5806):  at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:550) 
10-28 22:43:13.875: W/System.err(5806):  at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:509) 
10-28 22:43:13.875: W/System.err(5806):  at android.support.v4.view.ViewPager.setCurrentItem(ViewPager.java:490) 
10-28 22:43:13.875: W/System.err(5806):  at com.mike.myapp.MainActivity.onTabSelected(MainActivity.java:91) 
10-28 22:43:13.875: W/System.err(5806):  at com.android.internal.app.ActionBarImpl.selectTab(ActionBarImpl.java:572) 
10-28 22:43:13.875: W/System.err(5806):  at com.android.internal.app.ActionBarImpl$TabImpl.select(ActionBarImpl.java:1098) 
10-28 22:43:13.875: W/System.err(5806):  at com.android.internal.widget.ScrollingTabContainerView$TabClickListener.onClick(ScrollingTabContainerView.java:547) 
10-28 22:43:13.887: W/System.err(5806):  at android.view.View.performClick(View.java:4240) 
10-28 22:43:13.887: W/System.err(5806):  at android.view.View$PerformClick.run(View.java:17721) 
10-28 22:43:13.887: W/System.err(5806):  at android.os.Handler.handleCallback(Handler.java:730) 
10-28 22:43:13.895: W/System.err(5806):  at android.os.Handler.dispatchMessage(Handler.java:92) 
10-28 22:43:13.895: W/System.err(5806):  at android.os.Looper.loop(Looper.java:137) 
10-28 22:43:13.895: W/System.err(5806):  at android.app.ActivityThread.main(ActivityThread.java:5103) 
10-28 22:43:13.895: W/System.err(5806):  at java.lang.reflect.Method.invokeNative(Native Method) 
10-28 22:43:13.905: W/System.err(5806):  at java.lang.reflect.Method.invoke(Method.java:525) 
10-28 22:43:13.905: W/System.err(5806):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
10-28 22:43:13.905: W/System.err(5806):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
10-28 22:43:13.905: W/System.err(5806):  at dalvik.system.NativeStart.main(Native Method)

來源

2013-10-29 mike20132013

廣場這條線

lv1.setAdapter(new SimpleAdapter(getActivity(), jsonlist, R.layout.xyz, 
      new String[] { STATE }, new int[] { R.id.rowidtext }));

的JSON解析的東西之後。

和

for (int i = 0; i <= array.length(); i++)

要

for (int i = 0; i < array.length(); i++)

這是您的JSON

[ 
    { 
     "state": "JAVA", 
     "outdoorfun": "yes", 
     "additionalinfo": "{ search: 'online', website: 'http://states.arkansas.com', latitudeandlongitude: '93905, 63550}", 
     "cold": "no", 
     "type": "landlocked" 
    }, 
    { 
     "state": "ANDROID", 
     "outdoorfun": "no", 
     "additionalinfo": "{ search: 'online', website: 'http://states.chicago.com', latitudeandlongitude: '23905, 45355}", 
     "cold": "yes", 
     "type": "windy" 
    }, 
    { 
     "state": "CORE JAVA", 
     "outdoorfun": "no", 
     "additionalinfo": "{ search: 'online', website: 'http://states.chicago.com', latitudeandlongitude: '23905, 45355}", 
     "cold": "yes", 
     "type": "windy" 
    } 
]

，你可以看到，只有三元素JsonArray即（0， 1,2）但你正在嘗試要訪問index 3，所以org.json.JSONException: Value at 3 is null即將到來。我可以在日誌貓中看到所需的值，但是當我使用適配器時，屏幕會加載但我看不到數據。

當您嘗試設置適配器時，B'oz jsonlist爲空。

來源

2013-10-29 02:01:54

嘿..感謝您的答覆..其實我不知道在哪裏把適配器放在代碼中。你能幫我嗎。 – mike20132013

你說得對。 jsonlist是空的。 – mike20132013

@ mike20132013在此行之前放置適配器。 Log.i（「Data Coming？」，jsonlist.toString（））; –

從Assets文件夾解析JSON後，ListView中沒有加載值

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