ParseObject.pinAllInBackground（）結果與空指針異常

Question

我有一個News對象，它延伸ParseObject類。我希望它在本地緩存，以便我可以稍後從本地存儲中獲取它。

這裏是我的回調，包括調用.pinAllInBackground(..)方法：

FindCallback<News> onNewsReceived = new FindCallback<News>() { 

    @Override 
    public void done(List<News> arg0, ParseException arg1) { 

     if (arg1 == null) { 

      newsList = new ArrayList<News>(arg0); 
      ParseObject.pinAllInBackground(newsList); 
      initializeList(); 


     } else { 
      Log.d("TAG1", String.valueOf(arg1.getMessage())); 
     } 

    } 
}; 

當我運行此我得到以下異常：

09-22 11:31:25.637: E/AndroidRuntime(27380): FATAL EXCEPTION: main 
09-22 11:31:25.637: E/AndroidRuntime(27380): Process: pl.holdapp.osw, PID: 27380 
09-22 11:31:25.637: E/AndroidRuntime(27380): java.lang.NullPointerException 
09-22 11:31:25.637: E/AndroidRuntime(27380): at com.parse.ParsePin.getParsePin(ParsePin.java:19) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at com.parse.ParsePin.pinAllObjectsAsync(ParsePin.java:44) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at com.parse.ParseObject.pinAllAsync(ParseObject.java:3320) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at com.parse.ParseObject.pinAllInBackground(ParseObject.java:3417) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at pl.holdapp.osw.fragments.NewsFragment$2.done(NewsFragment.java:68) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at com.parse.FindCallback.internalDone(FindCallback.java:45) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at com.parse.FindCallback.internalDone(FindCallback.java:31) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at com.parse.Parse$6$1.run(Parse.java:917) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at android.os.Handler.handleCallback(Handler.java:733) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at android.os.Handler.dispatchMessage(Handler.java:95) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at android.os.Looper.loop(Looper.java:157) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at android.app.ActivityThread.main(ActivityThread.java:5356) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at java.lang.reflect.Method.invokeNative(Native Method) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at java.lang.reflect.Method.invoke(Method.java:515) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1265) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081) 
09-22 11:31:25.637: E/AndroidRuntime(27380): at dalvik.system.NativeStart.main(Native Method) 

arg0不爲空，所以我完全不瞭解來自哪裏。

Answer 1

顯然我沒有在釘住之前打電話Parse.enableLocalDatastore(context);。