c# - Sys.WebForms.PageRequestManagerServerErrorException : An entity object cannot be referenced by multiple instances of IEntityChangeTracker

Question

故事:

当我尝试保存一些东西时出现了一个奇怪的错误，我收到了这条错误消息

An entity object cannot be referenced by multiple instances of IEntityChangeTracker.

我真的不知道那是什么以及为什么会出现，只有当我尝试保存我的插入和更新正在工作的东西时，它才会出现，只有当我尝试从我的 Telerik 网格中保存一些东西到数据库中时才会出现

    if (this.annualVacationList != null)
        {
            List<AnnualVacation> vacationToSave = this.annualVacationList;
            IEnumerable<AnnualVacation> existing = paramUser.AnnualVacations;
            foreach (AnnualVacation toSave in vacationToSave)
            {
                AnnualVacation existingItem = existing.Where(x => x.AnnualVacationId == toSave.AnnualVacationId).SingleOrDefault();
                if (existingItem == null)
                {
                    ctx.AddToAnnualVacations(toSave);
                }
                else
                {
                    existingItem.FromDate = toSave.FromDate;
                    existingItem.ToDate = toSave.ToDate;
                    existingItem.WorkingTime = toSave.WorkingTime;
                    existingItem.VacationDays = toSave.VacationDays;
                }
            }
        }
        ctx.SaveChanges();
    }

调试后，我发现 Project.Name.Designer.cs 中的代码失效了 ..... 哦哦

  public void AddToAnnualVacations(AnnualVacation annualVacation)
    {
        base.AddObject("AnnualVacations", annualVacation);
    }

Answer 1

嘿嘿

我以某种方式自己得到它， View 状态没有分离上下文，这就是我刚刚创建的问题

var tmp = new AnnualVacation
                    {
                        FromDate = toSave.FromDate,
                        ToDate = toSave.ToDate,
                        WorkingTime = toSave.WorkingTime,
                        VacationDays = toSave.VacationDays,
                        UserId = toSave.UserId
                    };

在上面的同一个 if 查询中 (if(existing Item==null)) 并且它有效 但仍然感谢所有试图帮助我的人^^