Select e.DataCol.Name
Case "制单日期","工程代码"
If e.DataRow.IsNull("制单日期") OrElse e.DataRow.IsNull("工程代码") Then
e.DataRow("单据编号") = Nothing
Else
Dim d As Date = e.DataRow("制单日期")
Dim bh As String = e.DataRow("工程代码") & "-" & Format(d,"yyyyMMdd") & "-" '生成编号的前缀
If e.DataRow("单据编号").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
max = max = e.DataTable.Compute("Max(单据编号)","制单日期 = #" & d & "# And [_Identify] <> " & e.DataRow("_Identify")) '取得该天的最大编号
If max > "" Then '如果存在最大单据编号
idx = CInt(max.Substring(12,4)) + 1 '获得最大单据编号的后四位顺序号,并加1
Else
idx = 1 '否则顺序号等于1
End If
e.DataRow("单据编号") = bh & Format(idx,"0000")
End If
End If
End Select