Dim dt_xyk As DataTable = DataTables("信用卡")
Dim dt_lsz As DataTable = DataTables("流水账")
Dim dt_dyyh As DataTable = DataTables("出账")
dt_dyyh.DataRows.Clear
Dim d As Date = new Date(Date.Today.Year, Date.Today.Month, 1)
Dim ds() As Date = {d, d.AddMonths(1)}
d = d.AddMonths(-1)
For Each dr As DataRow In dt_xyk.DataRows
    Dim ndr As DataRow = dt_dyyh.AddNew
    ndr("账户名称") = dr("账户名称")
    ndr("卡号") = dr("卡号")
    ndr("账单日") = dr("账单日")
    ndr("起始记账日") = d.AddDays(dr("账单日"))
    ndr("本期支付") = dt_lsz.Compute("sum(金额)", "账户名称 = \'" & ndr("账户名称") & "\' and 日期 < #" & ndr("起始记账日") & "# and 类别 = \'转出\'")
    ndr("本期还款") = dt_lsz.Compute("sum(金额)", "账户名称 = \'" & ndr("账户名称") & "\' and 日期 < #" & ndr("起始记账日") & "# and 类别 = \'转入\'")
    ndr("信用额度") = dr("信用额度")
    ndr("本期应还") = ndr("本期支付") - ndr("本期还款")
      If dr("固定还款日") = False Then
        ndr("到期还款日") = cdate(ndr("起始记账日")).AddDays(dr("还款日"))
    Else
        If val(dr("还款日")) < val(dr("账单日")) Then
            ndr("到期还款日") = d.AddDays(dr("还款日")-1).AddMonths(1)
        Else
            ndr("到期还款日") = d.AddDays(dr("还款日")-1)
        End If
    End If
    If ndr("本期应还") > 0 Then
        If ndr("到期还款日") > Date.Today Then
            ndr("账单状态") = "已出账,没还款"
        Else
            ndr("账单状态") = "已出账,逾期还款"
        End If
    End If
    ndr("账单月") = Format(d, "yyyyMM")
Next
For Each d In ds
    For Each dr As DataRow In dt_xyk.DataRows
        Dim ndr As DataRow = dt_dyyh.AddNew
        ndr("账户名称") = dr("账户名称")
        ndr("卡号") = dr("卡号")
       ndr("账单日")=dr("账单日")
        ndr("起始记账日") = d.AddDays(dr("账单日"))
        ndr("本期支付") = dt_lsz.Compute("sum(金额)", "账户名称 = \'" & ndr("账户名称") & "\' and 日期 >= #" & ndr("起始记账日").addmonths(-1) & "# and 日期 <= #" & ndr("起始记账日")& "# and 类别 = \'转出\'")
        ndr("本期还款") = dt_lsz.Compute("sum(金额)", "账户名称 = \'" & ndr("账户名称") & "\' and 日期 >= #" & ndr("账单日").addmonths(-1) & "# and 日期 >= #" & ndr("起始记账日")& "# and 类别 = \'转入\'")
        Dim yq_out = dt_lsz.Compute("sum(金额)", "账户名称 = \'" & ndr("账户名称") & "\' and 日期 < #" & ndr("账单日").addmonths(-1) & "# and 类别 = \'转出\'")
        Dim yq_in = dt_lsz.Compute("sum(金额)", "账户名称 = \'" & ndr("账户名称") & "\' and 日期 < #" & ndr("账单日").addmonths(-1) & "# and 类别 = \'转入\'")
        ndr("信用额度") = dr("信用额度")
        ndr("本期应还") =  ndr("本期支付") - ndr("本期还款")
              If dr("固定还款日") = False Then
            ndr("到期还款日") = cdate(ndr("起始记账日")).AddDays(dr("还款日"))
        Else
            If val(dr("还款日")) < val(dr("账单日")) Then
                ndr("到期还款日") = d.AddDays(dr("还款日")-1).AddMonths(1)
            Else
                ndr("到期还款日") = d.AddDays(dr("还款日")-1)
            End If
        End If
        If ndr("本期应还") > 0 Then
            If ndr("起始记账日")> Date.Today Then
                ndr("账单状态") = "未出账,没还款"
            Else
                ndr("账单状态") = "已出账,没还款"
            End If
        Else
            If ndr("起始记账日")> Date.Today Then
                ndr("账单状态") = "未出账,没还款"
            Else
                ndr("账单状态") = "已出账,已还款"
            End If
        End If
        ndr("账单月") = Format(d, "yyyyMM")
    Next
Next

代码哪错了？运行后出错：

加上

cdate(ndr("起始记账日")).addmonths(-1)

cdate(ndr("账单日")).addmonths(-1)

不要乱改啊

http://www.foxtable.com/bbs/dispbbs.asp?boardid=2&id=113773&authorid=0&page=0&star=2

改成这样

ndr("账单日") = d.AddDays(dr("账单日"))
ndr("起始记账日") = d.AddDays(dr("账单日"))

如果还有问题上传实例测试。