主题：为什么重置列不变化

If e.DataCol.Name = "工序编号" Then
   
    Dim dys As List(Of String) = DataTables("工序单价表").GetUniqueValues("","工序编号")
    For Each dy As String In dys
        dim n as integer = 0
        Dim drs As List(Of DataRow)
        drs = DataTables("工序单价表").Select("[工序编号] = '" & dy & "'")
        For Each dr As Datarow In drs
            n = n + 1
            dr("规格次序") =Format(n,"000")
        Next
    next
    if e.dataRow.IsNull("工序编号")
        e.dataRow("规格次序") = ""
    end if
end if
If e.DataCol.Name = "工序编号" Then
    e.DataRow("工序规格码")=e.DataRow("工序编号") + e.DataRow("规格次序")
End If

先定工序编号列然后重置列，但发现工序规格码只有第一行起变化，如果一行行地选工序编码就能变化。为会什么呢？