If e.DataCol.Name = "日期" Then
If e.DataRow.IsNull("日期") Then
e.DataRow("单号") = Nothing
Else
Dim bh As String = Format(e.DataRow("日期"),"yyyyMMdd") \'取得单号的8位前缀
If e.DataRow("单号").StartsWith(bh) = False \'如果单号的前8位不符
Dim max As String
Dim idx As Integer
max = e.DataTable.Compute("Max(单号)","日期 = #" & e.DataRow("日期") & "# And [_Identify] <> " & e.DataRow("_Identify")) \'取得该天的最大单号
If max > "" Then \'如果存在最大单号
idx = CInt(max.Substring(9,3)) + 1 \'获得最大单号的后三位顺序号,并加1
Else
idx = 1 \'否则顺序号等于1
End If
e.DataRow("单号") = bh & "-" & Format(idx,"000")
End If
End If
End If