主题：[求助]

菜鸟求系统时间与某列的日期差，单位为“天”，不知道下面的代码哪里写错了，求助，谢谢

Select Case e.DataCol.name
    Case "第八列",e.NewValue(Date.Today)
        Dim dr As DataRow = e.DataRow
Dim d2 As Date = Date.Today
    d2 = e.NewValue(Date.Today)
        If dr.IsNull("第八列") Or dr.IsNull(d2) Then
           dr("第九列") = Nothing
        Else
            Dim tp As TimeSpan
            tp = dr(d2) - dr("第八列")
            dr("第九列") = tp.Days & "天" '真正的时段型数据要转换为秒数,才能存入时段列
        End If
End Select