主题：时间流水账

根据最后修改时间计算每行间隔的分钟，请教老师如何实现
此主题相关图片如下：qq截图20190617155002.jpg

Select Case e.DataCol.Name
    Case "第五列"
        Dim dr As DataRow
        Dim drs As List(of DataRow)
        dr = e.DataTable.Find("[_SortKey] < " & e.DataRow("_SortKey"), "[_SortKey] Desc") '找出上一行
        If dr Is Nothing Then '如果没有找到上一行,说明本行就是第一行
            e.DataRow("第六列") = 0
            dr = e.DataRow
        End If
        drs = e.DataTable.Select("[_SortKey] >= " & dr("_SortKey"), "[_SortKey]")
        For i As Integer = 1 To drs.Count - 1 '重算余下行的余额
            drs(i)("第六列") = (drs(i)("第五列")- drs(i-1)("第五列")).totalseconds
        Next   
End Select