小编use*_*331的帖子

我试图使用Dictionary重新编写一些代码来使用ConcurrentDictionary.我已经回顾了一些示例,但我仍然无法实现AddOrUpdate函数.这是原始代码:

    dynamic a = HttpContext;
    Dictionary<int, string> userDic = this.HttpContext.Application["UserSessionList"] as Dictionary<int, String>;

   if (userDic != null)
   {
      if (useDic.ContainsKey(authUser.UserId))
      {
        userDic.Remove(authUser.UserId);
      }
   }
  else
  {
     userDic = new Dictionary<int,string>();
  }
  userDic.Add(authUser.UserId, a.Session.SessionID.ToString());
  this.HttpContext.Application["UserDic"] = userDic;

我不知道要为更新部分添加什么:

userDic.AddOrUpdate(authUser.UserId,
                    a.Session.SessionID.ToString(),
                    /*** what to add here? ***/);

任何指针将不胜感激.