安卓異步任務for循環

我想從foor循環調用異步任務我該怎麼做？我已經做到了這一點安卓異步任務for循環

for (int i = 0; i < listimage.size(); i++) { 
      GlobalVariable.set_URL(listimage.get(i) + ""); 
      System.out.println("from fav " + GlobalVariable.get_URL() + ""); 
      try { 
       obj = new JSONObject(GlobalVariable.get_URL()); 
      } catch (JSONException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
      GetContacts gc = new GetContacts(); 
      gc.execute(); 

     }

我的logcat：

04-08 14:27:33.894: E/AndroidRuntime(2526): FATAL EXCEPTION: AsyncTask #5 
04-08 14:27:33.894: E/AndroidRuntime(2526): java.lang.RuntimeException: An error occured while executing doInBackground() 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at android.os.AsyncTask$3.done(AsyncTask.java:299) 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273) 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at java.util.concurrent.FutureTask.setException(FutureTask.java:124) 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307) 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at java.util.concurrent.FutureTask.run(FutureTask.java:137) 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230) 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076) 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569) 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at java.lang.Thread.run(Thread.java:856) 
04-08 14:27:33.894: E/AndroidRuntime(2526): Caused by: java.lang.NullPointerException 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at com.leeway.hdwallpaper.favourite_Activity$GetContacts.doInBackground(favourite_Activity.java:182) 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at com.leeway.hdwallpaper.favourite_Activity$GetContacts.doInBackground(favourite_Activity.java:1) 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at android.os.AsyncTask$2.call(AsyncTask.java:287) 
04-08 14:27:33.894: E/AndroidRuntime(2526):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305) 
04-08 14:27:33.894: E/AndroidRuntime(2526):  ... 5 more 
04-08 14:27:34.305: E/WindowManager(2526): Activity com.leeway.hdwallpaper.MainActivity has leaked window [email protected] that was originally added here 
04-08 14:27:34.305: E/WindowManager(2526): android.view.WindowLeaked: Activity com.leeway.hdwallpaper.MainActivity has leaked window [email protected] that was originally added here 
04-08 14:27:34.305: E/WindowManager(2526): at android.view.ViewRootImpl.<init>(ViewRootImpl.java:374) 
04-08 14:27:34.305: E/WindowManager(2526): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:297) 
04-08 14:27:34.305: E/WindowManager(2526): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:229) 
04-08 14:27:34.305: E/WindowManager(2526): at android.view.WindowManagerImpl$CompatModeWrapper.addView(WindowManagerImpl.java:154) 
04-08 14:27:34.305: E/WindowManager(2526): at android.view.Window$LocalWindowManager.addView(Window.java:547) 
04-08 14:27:34.305: E/WindowManager(2526): at android.app.Dialog.show(Dialog.java:285) 
04-08 14:27:34.305: E/WindowManager(2526): at com.leeway.hdwallpaper.favourite_Activity$GetContacts.onPreExecute(favourite_Activity.java:161) 
04-08 14:27:34.305: E/WindowManager(2526): at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586) 
04-08 14:27:34.305: E/WindowManager(2526): at android.os.AsyncTask.execute(AsyncTask.java:534) 
04-08 14:27:34.305: E/WindowManager(2526): at com.leeway.hdwallpaper.favourite_Activity.onCreateView(favourite_Activity.java:108) 
04-08 14:27:34.305: E/WindowManager(2526): at android.support.v4.app.Fragment.performCreateView(Fragment.java:1500) 
04-08 14:27:34.305: E/WindowManager(2526): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:927) 
04-08 14:27:34.305: E/WindowManager(2526): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104) 
04-08 14:27:34.305: E/WindowManager(2526): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682) 
04-08 14:27:34.305: E/WindowManager(2526): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1467) 
04-08 14:27:34.305: E/WindowManager(2526): at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:440) 
04-08 14:27:34.305: E/WindowManager(2526): at android.os.Handler.handleCallback(Handler.java:643) 
04-08 14:27:34.305: E/WindowManager(2526): at android.os.Handler.dispatchMessage(Handler.java:92) 
04-08 14:27:34.305: E/WindowManager(2526): at android.os.Looper.loop(Looper.java:137) 
04-08 14:27:34.305: E/WindowManager(2526): at android.app.ActivityThread.main(ActivityThread.java:4803) 
04-08 14:27:34.305: E/WindowManager(2526): at java.lang.reflect.Method.invokeNative(Native Method) 
04-08 14:27:34.305: E/WindowManager(2526): at java.lang.reflect.Method.invoke(Method.java:511) 
04-08 14:27:34.305: E/WindowManager(2526): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789) 
04-08 14:27:34.305: E/WindowManager(2526): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556) 
04-08 14:27:34.305: E/WindowManager(2526): at dalvik.system.NativeStart.main(Native Method)

這是我getcontact.doinbackground

protected Void doInBackground(Void... params) { 
    sample = new ArrayList<String>(); 

    contactList = new ArrayList<HashMap<String, String>>(); 
    gv = (GridView) getActivity().findViewById(R.id.gridView1); 

    ServiceHandler sh = new ServiceHandler(); 


    String jsonStr = sh.makeServiceCall(obj.toString(), 
      ServiceHandler.GET); 
    System.out.println("this is from do in.." 
      + GlobalVariable.get_URL() + ""); 
    Log.d("Response: ", "> " + jsonStr); 

    if (jsonStr != null) { 
     try { 
      JSONObject jsonObj = new JSONObject(jsonStr); 

      // Getting JSON Array node 
      contacts = jsonObj.getJSONArray(TAG_WALLPAPER); 

      // looping through All Contacts 
      for (int i = 0; i < contacts.length(); i++) { 
       JSONObject c = contacts.getJSONObject(i); 

       String id = c.getString(TAG_ID); 

       // Phone node is JSON Object 

       JSONObject phone = c.getJSONObject(TAG_IMAGE); 

       String thumb = phone.getString(TAG_THUMB); 
       String android = phone.getString(TAG_IMAGE_ANDROID); 

       // img_url.add(thumb); 
       // grdadpter ga = new grdadpter(getActivity(), sample); 
       // gv.setAdapter(ga); 
       // String office = phone.getString(TAG_IMAGE_OFFICE); 

       // tmp hashmap for single contact 
       HashMap<String, String> contact = new HashMap<String, String>(); 

       // adding each child node to HashMap key => value 
       contact.put(TAG_ID, id); 
       img_ID.add(id); 
       // adding contact to contact list 
       contactList.add(contact); 
       // sample.add(thumb); 
       publishProgress(thumb); 
       android_img.add(android); 
       System.out.println("this is from do in ng.." 
         + sample.size()); 

      } 
     } catch (JSONException e) { 
      e.printStackTrace(); 
     } 
    } else { 
     Log.e("ServiceHandler", "Couldn't get any data from the url"); 
    } 

    return null; 

}

來源

2014-04-08 Android

可以請您展示'GetContacts'類嗎？ – nikis

看到我更新的問題 – Android

'favourite_Activity.java：182'上有什麼？ – nikis

試試這個..

我猜你沒有用來初始化img_IDArrayList在你的0123裏初始化它像下面一樣。

img_ID = new ArrayList<String>();

編輯：

同樣喜歡，你不能用來初始化你GridView內doInBackground刪除它這樣做，在Activity或Fragment

來源

2014-04-08 09:15:14 Hariharan

沒有不是這個概率..我已經完成了這個 – Android

@Pragna看到我的編輯。 – Hariharan

因爲你不是在你的異步調用不會返回任何東西它是

new GetContacts().execute();

或您需要廣告只是你的異步調用返回聯繫人？

來源

2014-04-08 09:20:57 nivensookharan

for (int i = 0; i < listimage.size(); i++) { 
      GlobalVariable.set_URL(listimage.get(i) + ""); 
      System.out.println("from fav " + GlobalVariable.get_URL() + ""); 
      try { 
       obj = new JSONObject(GlobalVariable.get_URL()); 
      } catch (JSONException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
      GetContacts gc = new GetContacts(); 
      gc.execute(); 

     } 

change to 

for (int i = 0; i < listimage.size(); i++) { 
      GlobalVariable.set_URL(listimage.get(i) + ""); 
      System.out.println("from fav " + GlobalVariable.get_URL() + ""); 
      try { 
       obj = new JSONObject(GlobalVariable.get_URL()); 
      } catch (JSONException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
      GetContacts gc[i] = new GetContacts(); 
      gc[i].execute(); 

     }

來源

2014-04-08 09:22:14 Mario

AsynTask in for循環？您的for循環將不會等待AsyncTask完成。而在給定的時間最多隻允許5個AsynTask。

來源

2014-04-08 09:24:44 Praveen

安卓異步任務for循環

回答

相關問題