我写了一下，大概是这意思，但红色标注报错：
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
di = "yz-" & y & Format(m,"00") & "-0001" '编号前缀,2位前缀,4位年,2位月
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
[此贴子已经被作者于2021/1/10 17:50:37编辑过]
加好友 
发短信
Post By：2021/1/9 11:09:00 [显示全部帖子]
此主题相关图片如下：5.png
,我重写，写好再问你。