主题：[求助]入库单号加1

If DataTables("U8物料数量汇总表").DataRows.Count >0  Then
    Dim rklb As WinForm.ComboBox = e.Form.Controls("ComboBox2")
    Dim kwlb As WinForm.ComboBox = e.Form.Controls("ComboBox3")
    Dim rkdh As WinForm.TextBox = e.Form.Controls("TextBox14")
    If rklb.text <> "请选择入库类别" And kwlb.text <> "请选择库位类别" Then
        Dim d As Date = Date.Today
        Dim y As Integer = d.Year
        Dim m As Integer = d.Month
        Dim r As Integer = d.day
        Dim bh As String = "PKRK" & rklb.text & kwlb.text & Format(d,"yyyyMMdd") '生成编号的前6位,4位年,2位月.
        Dim max As String
        Dim idx As Integer
        max = DataTables("U8物料数量汇总表").SQLCompute("Max(入库单号)","入库单号 like '" & bh & "%'")
       
        If max > "" Then '如果存在最大编号
            idx = CInt(max.Substring(bh.length)) + 1 '获得最大编号的后五位顺序号,并加1
           
        Else
            idx = 1 '否则顺序号等于1
        End If
        rkdh.text =  bh & Format(idx,"0000")
        For Each dr As DataRow In DataTables("U8物料数量汇总表").DataRows
            If dr.IsNull("入库单号")= True Then
                dr("入库单号")  = rkdh.text ----希望循环时每行的每个入库单号都是上一行的入库单号加1，而不是固定的。
                dr("库位类别") = kwlb.text
                dr("实扫到数量") = 0
                dr("生成入库单时间") = Date.Now
                dr("状态") = "生成入库单"
                dr.Save
            End If
        Next
    Else
        Dim str As String
        If rklb.text = "请选择入库类别" Then
            str & = "入库类别,"
        End If
        If kwlb.text = "请选择库位类别" Then
            str & = "库位类别"
        End If
        If str > "" Then
            MessageBox.show("请选择" & str.Trim(","),"提示",MessageBoxButtons.OK,MessageBoxIcon.Error)
        End If
    End If
Else
    MessageBox.show("请先导入U8物料编码收货单","U8物料编码收货单数据为空",MessageBoxButtons.OK,MessageBoxIcon.Error)
End If

        For Each dr As DataRow In DataTables("U8物料数量汇总表").DataRows
            If dr.IsNull("入库单号")= True Then

                rkdh.text =  bh & Format(idx,"0000")

                idx += 1
                dr("入库单号") = rkdh.text ----希望循环时每行的每个入库单号都是上一行的入库单号加1，而不是固定的。