主题：求编号的自动生成代码

如果要达到上面的代码,一句就可以了:

If e.DataCol.Name = "日期" Then
    e.DataRow("编号")  = "AA"& Format(e.DataRow("日期"),"yyMMdd") & Format(e.DataTable.Compute("count(日期)", "[日期] = #" & e.DataRow("日期")  & "# And [_identify] < 50" & e.DataRow("_Identify")),"0000")
End If

如果是这个效果:

If e.DataCol.Name = "日期" Then
    If e.DataRow.IsNull("日期") Then
        e.DataRow("编号") = Nothing
    Else
        If e.NewValue <> Nothing And e.DataRow("编号") = Nothing Then
            Dim s As String ="AA" & format(e.DataRow("日期"),"yyMMdd")    '只修改了这个地方···
            Dim i1 As String = e.DataTable.Compute("Max(第三列)", "[日期] = #" & e.DataRow("日期")  & "#" )
            Dim n As Integer
            If s = left(i1,8) Then
                n=CInt(right(i1,3))
            Else
                n=0
            End If
            s= s & format(n+1,"000")
            e.DataRow("第三列")=s
        End If
    End If
End If