在POOrderEntry中更新缓存时发生异常

Question

在创建采购订单后添加SOLine时，SOLineSplit中“ POType”，“ PONbr”，“ POLineNbr”，“ RefNoteID”的值将存储为NULL值。

当我在创建的采购订单中添加相同的SOLine时，我试图用POLine值更新SOLineSplit NULL值，但是在弹出窗口中出现错误，提示“订单日期不能为空”。下面是我在事件中编写的用于更新Cache中的值但在graph.Actions.PressSave（）;中获取异常的代码。有人可以帮我吗？

     public PXSelectJoin<SOLineSplit, InnerJoin<POOrder, On<SOLineSplit.orderType, Equal<POOrder.sOOrderType>,
                                                      And<SOLineSplit.orderNbr, Equal<POOrder.sOOrderNbr>>>>,
                                                      Where<SOLineSplit.pOType, IsNull, And<SOLineSplit.pONbr, IsNull>>> UnmappedSoLine;


    protected void POOrder_RowPersisted(PXCache sender, PXRowPersistedEventArgs e, PXRowPersisted BaseEvent)
    {


        POOrder row = e.Row as POOrder;
        if (row != null && e.TranStatus == PXTranStatus.Completed)
        {
            SOLinePartial graph = PXGraph.CreateInstance<SOLinePartial>();
            foreach (POLine poline in Base.Transactions.Select())
            {
                foreach (SOLineSplit sosplititem in UnmappedSoLine.Search<SOLineSplit.inventoryID>(poline.InventoryID))
                {
                    sosplititem.POType = poline.OrderType;
                    sosplititem.PONbr = poline.OrderNbr;
                    sosplititem.POLineNbr = poline.LineNbr;
                    sosplititem.OrderDate = poline.OrderDate;
                    SOLineSplit sp = PXSelectJoin<SOLineSplit,
                InnerJoin<POLine, On<
                SOLineSplit.pOType, Equal<POLine.orderType>,
                                And<SOLineSplit.pONbr, Equal<POLine.orderNbr>, And<SOLineSplit.pOLineNbr, Equal<POLine.lineNbr>>>>>,
               Where<POLine.orderNbr, Equal<Required<POOrder.orderNbr>>>>.Select(Base, row.OrderNbr);
                    if (sp != null)
                        sosplititem.RefNoteID = sp.RefNoteID;

                    graph.soLineSplit.Cache.Update(sosplititem);
                }


            }

            graph.Actions.PressSave();
        }          


    }