服务端的设计

1、在服务端的全局代码中编写代码：

Public flbhs As new Dictionary(of String,Integer)

2、在服务端的AfterOpenProjet事件中编写代码：

Dim dt As DataTable
Dim cmd As New SQLCommand
cmd.ConnectionName = "数据源名称"
cmd.CommandText = "Select Year(日期) As 年, Month(日期) As 月, Max(编号) as 编号 Fro m {订单} Group By Year(日期), Month(日期)"
dt = cmd.ExecuteReader
flbhs.Clear()
For Each dr As DataRow In dt.DataRows
    Dim qz As String = dr("年") & Format(dr("月"),"00") \'编号前缀,4位年,2位月
    Dim bh As String = dr("编号")
    Dim id As Integer
    If bh.Length = 10 Then
        bh = bh.SubString(7)
        If Integer.TryParse(bh,id) Then
            flbhs.Add(qz, id)
        End If
    End If
Next

上述代码在启动项目后，用SQL语句提取现有数据的每月最大编号，将其整数部分存储在字典flbhs中。

3、在服务端的OpenQQ服务端事件ReceivedMessage中编写代码：

Dim msg As String = e.Message
If msg.StartsWith(":p") AndAlso msg.EndsWith("p:") Then
    msg = msg.SubString(2, msg.Length - 4)
    If flbhs.ContainsKey(msg) Then \'如果存在这个月的编号
        flbhs(msg) = flbhs(msg) + 1 \'将该月最大编号加1
    Else
        flbhs.Add(msg,1) \'如果是这个月的首次编号,则编号等于1
    End If
    e.ReturnValue = flbhs(msg) \'将编号返回给客户端
End If

客户端的设计

选择客户端项目的订单表，在其DataColChanged事件中加上代码：

If e.DataCol.Name = "日期" Then
    If e.DataRow.IsNull("日期") Then
        e.DataRow("编号") = Nothing
    Else
        If QQClient.Ready = False Then
            PopMessage("QQClient未启动,无法生成编号!","提示",PopIconEnum.Infomation,5)
        Else
            Dim bh As String = Format(e.DataRow("日期"),"yyyyMM")
            Dim rt As String =  QQClient.SendWait(":p" & bh & "p:")
            Dim id As Integer
            If rt > "" Then
                If  Integer.TryParse(rt,id)  Then
                    e.DataRow("编号") = bh & "-" & Format(id,"000")
                Else
                    PopMessage("服务器返回错误信息:" & rt,"提示",PopIconEnum.Infomation,5)
                End If
            Else
                PopMessage("服务器无响应,无法生成编号!","提示",PopIconEnum.Infomation,5)
            End If
        End If
    End If
End If