获取DataRow的最后一行数据

      //师资团队
        dt = TeacherService.GetTeacher();
        foreach (DataRow dr in dt.Rows)
        {
            teachercontent += "<li><a href=\"teacher.aspx?teacher_id=" + dr["TEACHER_Id"].ToString() + "\" class=\"\">" + dr
            ["TEACHER_CName"].ToString() + "</a></li>";
             //获取最后一行
            if (dt.Rows.IndexOf(dr) == dt.Rows.Count - 1)
            {
                teachercontent += "<li><a href=\"teacher.aspx?teacher_id=" + dr["TEACHER_Id"].ToString() + "\" class=\"navact1\">" +  dr["TEACHER_CName"].ToString() + "</a></li>";
            }

}

做菜单选项的时候想要最后一行的样式跟其他的不一样，所以就想到先获取最后一行数据，在单独捆绑样式