即使使用AsyncTask也會拋出NetworkOnMainThread異常

Question

以下是我的Fragment中的AsyncTask類，當我單擊片段時，出現此錯誤： NetworkOnMainThread異常（由於我的信譽不夠高，我無法發佈圖像）

private class me extends AsyncTask<Object,Void,Boolean>{ 
      DisplayMetrics dm = new DisplayMetrics(); 

      protected void onPreExecute(){ 
       String sess = SignIn.giveSession().getSession().getToken(); 


       deviceId = device.getDeviceId(); 
       data = RestQuery.profileImage(sessionToken, deviceId, username); 
       bm = BitmapFactory.decodeByteArray(data,0,data.length); 
       getActivity().getWindowManager().getDefaultDisplay().getMetrics(dm); 


       username = reWiPr.getName(); 



      } 

      protected Boolean doInBackground(Object... stuff){ 
       if(reWiPr == null){ 
        return false; 
       } 

       return true; 
      } 

      protected void onPostExecute(Boolean results){ 
       if(results){ 
        image.setMinimumHeight(dm.heightPixels); 
        image.setMinimumWidth(dm.widthPixels); 
        image.setImageBitmap(bm); 

        uName.setText(reWiPr.getName()); 
        rName.setText(reWiPr.getRealName()); 
        safety.setText("Safety: " + reWiPr.getRating().getSafe()); 
        time.setText("Time: " + reWiPr.getRating().getTime()); 
        courteous.setText("Courteous: " + reWiPr.getRating().getCourteous()); 
        cleanliness.setText("Cleanliness: " + reWiPr.getRating().getClean()); 
        overall.setText("Overall: " + reWiPr.getRating().getOverall()); 
        average.setText("Average: " + reWiPr.getRating().getAverage()); 
        ve.setText("Vehicles: " + reWiPr.getVehicle()); 


       } 
      } 

我該如何解決這個問題？我需要這個AsyncTask來使這個片段工作，並且我在onCreate（）方法中執行它。任何幫助，將不勝感激謝謝。*

Answer 1

你沒有以正確的方法進行網絡調用。你必須移動你的網絡電話doInBackground，我現在看到它在onPreExecute。

從文檔：

When an asynchronous task is executed, the task goes through 4 steps:

1. onPreExecute(), invoked on the UI thread before the task is executed. This step is normally used to setup the task, for instance by showing a progress bar in the user interface.
2. doInBackground(Params...), invoked on the background thread immediately after onPreExecute() finishes executing. This step is used to perform background computation that can take a long time. The parameters of the asynchronous task are passed to this step. The result of the computation must be returned by this step and will be passed back to the last step. This step can also use publishProgress(Progress...) to publish one or more units of progress. These values are published on the UI thread, in the onProgressUpdate(Progress...) step.
3. onProgressUpdate(Progress...), invoked on the UI thread after a call to publishProgress(Progress...). The timing of the execution is undefined. This method is used to display any form of progress in the user interface while the background computation is still executing. For instance, it can be used to animate a progress bar or show logs in a text field.
4. onPostExecute(Result), invoked on the UI thread after the background computation finishes. The result of the background computation is passed to this step as a parameter.

Answer 2

你需要做你的網絡任務中doInBackground方法。目前您已在onPreExecute中運行GUI線程。