主题：录入凭证设计

Dim yzdh As WinForm.TextBox = e.Form.Controls("dh")'dh是单号控件

Dim di As String = yzdh.Value 'di单号控件中的变量

Dim bsrq As WinForm.DateTimePicker = Forms("月租收费").Controls("rq")

Dim d As Date = bsrq.Value

If d = "" Then

    messagebox.show("请选择日期")

    Return

    Dim y As Integer = d.Year

    Dim m As Integer = d.Month

ElseIf DataTables("缴费情况").Compute("Count([单号])","[前缀] = 'yz'") = 0 Then

Else

    Dim dt As DataTable

    Dim cmd As New SQLCommand

    'cmd.C

    cmd.CommandText = "Select 前缀,Year(日期) As 年, Month(日期) As 月, Max(单号) as 单号 Fr om {缴费情况} Group By 前缀,Year(日期), Month(日期)"

    dt = cmd.ExecuteReader

    flbhs.Clear()

    For Each dr As DataRow In dt.DataRows

        Dim qz As String = dr("前缀") & "-"  & dr("年") & Format(dr("月"),"00") '编号前缀,2位前缀,4位年,2位月

        Dim bh As String =  dr("单号")

        Dim id As Integer

        If bh.Length = 14 Then

            bh = bh.SubString(10)

            If Integer.TryParse(bh,id) Then

                flbhs.add(qz, id+1)

            End If

        End If

    Next

    di = flbhs.add(qz, id+1)

End If