Select e.DataCol.Name
Case "编号"
If e.DataRow.IsNull("编号") Then
e.DataRow("菜单编号") = Nothing
Else
Dim lb As String = e.DataRow("编号")
If e.DataRow("菜单编号").StartsWith(lb) = False \'如果单据编号前缀不符
Dim max As String
Dim idx As Integer
max = e.DataTable.Compute("Max(菜单编号)","编号 = \'" & lb & "\' And [_Identify] <> " & e.DataRow("_Identify")) \'取得该类别的最大编号
If max > "" Then \'如果存在最大编号
idx = CInt(max.Substring(2,3)) + 1 \'获得最大编号的后三位顺序号,并加1
Else
idx = 1 \'否则顺序号等于1
End If
e.DataRow("菜单编号") = lb & Format(idx,"00")
End If
End If
End Select