private void unfollowQuestion() {
   if (unfollowTask != null && unfollowTask.getStatus() == AsyncTask.Status.RUNNING) {
     unfollowTask.cancel(true);
   }
   unfollowTask = new UnfollowTask();
   unfollowTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, question.getId());
 }
 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
   // Handle action bar item clicks here. The action bar will
   // automatically handle clicks on the Home/Up button, so long
   // as you specify a parent activity in AndroidManifest.xml.
   int id = item.getItemId();
   switch (id) {
     case R.id.action_follow_question:
       followQuestion();
       break;
     case R.id.action_unfollow_question:
       unfollowQuestion();
       break;
     case R.id.action_open_in_browser:
       if (!TextUtils.isEmpty(question.getUrl())) {
         MobclickAgent.onEvent(this, Mob.Event_Open_Question_In_Browser);
         UrlCheckUtil.openWithBrowser(question.getUrl());
       }
       break;
     case R.id.action_share_to_wechat_circle:
       MobclickAgent.onEvent(this, Mob.Event_Share_Question_To_Wechat_Circle);
       ShareUtil.shareToWeiXinCircle(
           this, question.getUrl(), question.getTitle(), question.getSummary(), null);
       break;
     case R.id.action_share_to_wechat_friends:
       MobclickAgent.onEvent(this, Mob.Event_Share_Question_To_Wechat_friend);
       ShareUtil.shareToWeiXinFriends(
           this, question.getUrl(), question.getTitle(), question.getSummary(), null);
       break;
     case R.id.action_share_to_weibo:
       MobclickAgent.onEvent(this, Mob.Event_Share_Question_To_Weibo);
       ShareUtil.shareToWeibo(
           this, question.getUrl(), question.getTitle(), question.getSummary(), null);
       break;
   }
   return super.onOptionsItemSelected(item);
 }