AsyncTask：將異常值從doInBackground傳遞到onPostExecute

Question

我試圖將我的doInBackground之間的錯誤消息傳遞到我的onPostExecute。有沒有辦法使用數據結構來做到這一點？在我的情況我我我試圖避免使一個類，並返回一個對象

    @Override 
     protected User doInBackground(List<Pair<String, String>>... params) { 
      randomAPI api = randomAPI 
        .getInstance(context); 

      try { 
       **thing that will generate error** 
       } 

      } catch (RandomException e) { 
       Log.e(TAG, "Error", e); 
      } 
      return somethingThatIsUsableInOnPostExecute; 
     } 

     @Override 
     protected void onPostExecute(User result) { 

      } 

Answer 1

private String exception = ""; 
@Override 
    protected User doInBackground(List<Pair<String, String>>... params) { 
     randomAPI api = randomAPI 
       .getInstance(context); 

     try { 
      **thing that will generate error** 
      } 

     } catch (RandomException e) { 
      Log.e(TAG, "Error", e); 
      exception = e.getMessage(); 
     } 
     return somethingThatIsUsableInOnPostExecute; 
    } 

    @Override 
    protected void onPostExecute(User result) { 
      if(!exception.isEmpty()){ 
       //exception path 
      } 
     } 

Answer 2

，你應該嘗試從 User對象改變return類型的doInBackground到Object和onPostExecute投它。