这是controller中的一段代码

 public JsonResult GetList(GridPager pager, string queryStr)
        {
            List<SysException> list = exceptionBLL.GetList(ref pager, queryStr);
            var json = new
            {
                total = pager.totalRows,
                rows = (from r in list
                        select new SysException()
                        {
                            Id = r.Id,
                            HelpLink = r.HelpLink,
                            Message = r.Message,
                            Source = r.Source,
                            StackTrace = r.StackTrace,
                            TargetSite = r.TargetSite,
                            Data = r.Data,
                            CreateTime = r.CreateTime
                        }
                ).ToArray()
            };
            return Json(json);
        }

这段代码中

 List<SysException> list = exceptionBLL.GetList(ref pager, queryStr);

list =null

下面这句肯定会出现异常

from r in list
select new SysException(){....}

要怎么处理才好呢

因为是在controller中最好是不要写什么逻辑代码