private UserEventInfo GetUserEventInfo(int eventId) { if (!userInfo.ContainsKey(eventId)) { var eventData = dddEventDataInfo.SingleOrDefault(x => x.eventId == eventId); if (eventData == null) { return(null); } var userName = eventData.userToken != null?userService.GetUserName(eventId, eventData.userToken) : null; userInfo.Add(eventId, new UserEventInfo { EventId = eventId, UserName = userName, UserToken = eventData.userToken }); } return(userInfo[eventId]); }