主题：怎样计算第几周

If e.DataCol.Name = "日期" Then

    If e.DataRow.IsNull("日期") Then

        e.DataRow("第几周") = Nothing

    Else

        Dim calCommon  As New System.Globalization.GregorianCalendar()

        Dim dt As Date = e.DataRow("日期")

        e.DataRow("第几周") = calCommon.GetWeekOfYear(dt, System.Globalization.CalendarWeekRule.FirstDay, 0)

    End If

End If