Sys.WebForms.PageRequestManagerServerErrorException：一个实体对象不能被IEntityChangeTracker的多个实例引用

Question

故事：

我有一个奇怪的错误，当我试图保存的东西，我得到这个错误信息

实体对象不能被IEntityChangeTracker的多个实例引用。

我真的不知道为什么会出现那是什么，并且它，当我尝试保存我的东西插入和更新工作，只有当我尝试保存在数据库的东西从我Telerik的电网只出现

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(); 
    } 

调试我看到后，该代码拆毁在Project.Name.Designer.cs .....吴

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

Answer 1

Heey

我自己莫名其妙viewstates不拆的背景下得到它，这是我刚刚创建

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

在同一

的问题，如果查询是以上（如果（现有项目== NULL）），它作品 ，但仍然感谢大家试图帮助我^^