主题：求助，为什么有个累计出货数据每次打开就清零了？

http://www.foxtable.com/help/topics/1380.htm

'根据出库明细表中订单行号的开piao情况得出本行是否开piao
If e.DataCol.name = "开piao否" Then

    Dim flag As Boolean = True
    Dim drs As List(Of DataRow)
    drs = DataTables("出库明细").Select( " [客户订单号] =  '"& e.DataRow("客户订单号") & "'  And [订单行号] =   '"& e.DataRow("订单行号") & "'   " )
    For Each dr As DataRow In drs
        If dr("开piao否") = False Then
            flag = False
            Exit For
        End If
    Next
    If flag AndAlso e.DataRow("未交货数量") <= 0 Then
        e.DataRow("开piao否") = True
    Else
        e.DataRow("开piao否") = False
    End If
End If