DataColChanged事件中：

Select e.DataCol.Name
    Case "登记时间","工程编号" ,"合同编号","子目号","计价开始时间","计价结束时间","计价编号"
        If e.DataRow.IsNull("登记时间") OrElse e.DataRow.IsNull("合同编号") OrElse e.DataRow.IsNull("工程编号") OrElse e.DataRow.IsNull("计价开始时间")  OrElse e.DataRow.IsNull("计价结束时间") Then
            e.DataRow("计价编号") = Nothing
        Else
            Dim d As Date = e.DataRow("登记时间")
            Dim d1 As Date = e.DataRow("计价开始时间")
            Dim d2 As Date = e.DataRow("计价结束时间")
            \'Dim dr1 As DataRow
            \'Dim dr2 As DataRow
            Dim bh As String = e.DataRow("合同编号")  & "-" & "Y13" & "-" \'生成编号的前缀
            If e.DataRow("计价编号").StartsWith(bh) = False \'如果单据编号前缀不符
                Dim max As String
                Dim idx As Integer
                Dim flt As String
            flt = "合同编号 = \'" & e.DataRow("合同编号") & " \' and 子目号 = \'" & e.DataRow("子目号") & "\' And #" & d2 & "#  >#" & d1 & "#  And [_Identify] <> "  &  e.DataRow("_Identify")
                max = e.DataTable.Compute("Max(计价编号)",flt)
                If max > "" Then
                    idx = CInt(max.Substring(27,2)) + 1 \'获得最大单据编号的后二位顺序号,并加1
                Else
                    idx = 1 \'否则顺序号等于1
                End If
                e.DataRow("计价编号") = bh & Format(idx,"00")
            End If
        End If