明细合计回写总表的处理，应在Presenter的DoBeforePost中处理,如

protected override void DoBeforePost(object sender, BeforeEventArgs e)

{

    base.DoBeforePost(sender, e);

    MasterEntitySet.Current.Quantity = MasterEntitySet.Current.SdQuotationItem.Sum(i => i.Quantity);

    MasterEntitySet.Current.Amount = MasterEntitySet.Current.SdQuotationItem.Sum(i => i.Amount);

}