Entity FrameWork的问题，急急急！！！

Question

我在给new出的对象的属性一一赋值完成后， 调用 ObjectContext.SaveChanged()时;引发了一个异常， 不好意思没办法截图  提示的异常消息是 【未能比较数组中的两个元素】注：1、我没对对象进行排序
    2、我要保存的对象的关联对象都是通过查询得到的
    3、所有操作都是在一个 ObjectContext 操作的！请给小弟个指引，不胜感激！！

Answer 1

public StockOut AddStockOut(StockOut stockOut)
        {
            MTMSEntities context = ContextFactory.Create();
            Validate(context, stockOut);            StockOut newStockOut = new StockOut();
            newStockOut.ID = Guid.NewGuid().ToString("N");
            newStockOut.StockOutCode = stockOut.StockOutCode;
            newStockOut.ContactUnit = context.ContactUnits.Where(c => c.ID == stockOut.ContactUnit.ID).FirstOrDefault();
            newStockOut.CreateUser = stockOut.CreateUser;
            newStockOut.CreateDate = stockOut.CreateDate;
            newStockOut.ModifyUser = stockOut.ModifyUser;
            newStockOut.ModifuDate = stockOut.ModifuDate;
            newStockOut.AuditUser = stockOut.AuditUser;
            newStockOut.AuditDate = stockOut.AuditDate;            foreach (StockOutDetail item in stockOut.StockOutDetails)
            {
                StockOutDetail newStockOutDetail = new StockOutDetail();
                newStockOutDetail.ID = Guid.NewGuid().ToString("N");
                newStockOutDetail.Product = context.Products.Where(c => c.ID == item.Product.ID).FirstOrDefault();
                newStockOutDetail.Packages = item.Packages;
                newStockOutDetail.Price = item.Price;
                newStockOutDetail.Quality = item.Quality;
                newStockOutDetail.Quantity = item.Quantity;
                newStockOutDetail.StockOut = newStockOut;                newStockOut.StockOutDetails.Add(newStockOutDetail);
            }            context.AddToStockOuts(newStockOut);
            context.SaveChanges();
            return newStockOut;
        }
这是那个功能的代码  异常出现就是在 context.SaveChanges();的时候！