请教计算剩余天数,下面代码提示错误,请老师指导一下
Select Case e.DataCol.Name
Case "到期日期"
Dim dr As DataRow = e.DataRow
Dim d As Date = Date.Today
If dr.IsNull("到期日期") Then
dr("剩余天数") = Nothing
Else
Dim tp As TimeSpan = dr("到期日期") - d
dr("剩余天数") = tp.TotalDays
End If
End Select