Dim dr As DataRow = e.DataRow
Dim pf As String
If dr.RowState <> DataRowState.Added Then \'如果不是新增行
Return \'那么返回
ElseIf dr.IsNull("日期") Then \'如果没有输入日期
e.Cancel = True \'取消保存此行
MessageBox.Show("必须输入日期!","提示",MessageBoxButtons.OK,MessageBoxIcon.Information)
Return
Else
pf = Format(dr("日期"),"yyMM") \'否则获得编号的前缀,两位年,两位月
End If
Dim cmd1 As New SQLCommand
Dim cmd2 As New SQLCommand
Dim Key As Integer
Dim nm As String = e.DataTable.name
cmd1.ConnectionName = "编号" \'设置数据源名称
cmd2.ConnectionName = "编号"
cmd1.commandText = "Select Count(*) From [编号] Where [前缀] = \'" & pf & "\' And 表名 = \'" & nm & "\'"
If cmd1.ExecuteScalar = 0 Then \'如果编号表不存在前缀的行,那么增加一行
cmd1.commandtext = "Insert Into 编号 (表名, 前缀, 顺序号) Values(\'" & nm & "\',\'" & pf & "\',1)"
cmd1.ExecuteNonQuery
End If
cmd1.commandText = "Select [顺序号] From [编号] Where [前缀] = \'" & pf & "\' And 表名 = \'" & nm & "\'"
Do
Key = cmd1.ExecuteScalar() \'从后台获得顺序号
cmd2.commandText = "Update [编号] Set [顺序号] = " & (Key + 1) & " Where [顺序号] = " & Key & " And [前缀] = \'" & pf & "\' And 表名 = \'" & nm & "\'"
If cmd2.ExecuteNonQuery() > 0 Then \'更新顺序号
Exit Do \'更新成功则退出循环
End If
Loop
e.DataRow("编号") = pf & "-" & Format(Key,"0000")

 这段代码 我只要尾数为4就避开 怎么修改代码

 取出每一位，看是不是4，如果是，对应的位置就+1