问如何从非静态类ASP.Net c#设置接口可见性

EN

private static List<DayOfWeek> days = new List<DayOfWeek>();

private static List<WhatsMyDay> myDays = new List<WhatsMyDay>();

  public class WhatsMyDay
  {
    public WhatsMyDay(DayOfWeek day, DropDownList am, 
                        DropDownList pm, HtmlTableCell dTitle)
    {
        Day = day;
        ddlAM = am;
        ddlPM = pm;
        tdTitle = dTitle;
    }

    public DayOfWeek Day { get; private set; }
    private static DropDownList ddlAM { get; set; }
    private static DropDownList ddlPM { get; set; }
    private static HtmlTableCell tdTitle { get; set; }

    public int? AM
    {
        get { 
            return Convert.ToInt32(ddlAM.SelectedValue) == -1 
                ? null 
                : (int?)Convert.ToInt32(ddlAM.SelectedValue); 
        }
    }

    public int? PM
    {
        get { 
            return Convert.ToInt32(ddlPM.SelectedValue) == -1 
                    ? null 
                    : (int?)Convert.ToInt32(ddlPM.SelectedValue); 
        }
    }

    public void ShowHideInterface(bool visiblity)
    {
        tdTitle.Visible = visiblity;
    }
}

protected void Page_Load(object sender, EventArgs e)
{
    days.Add(DayOfWeek.Monday);
    myDays.Add(new WhatsMyDay(
            DayOfWeek.Monday, ddlMondayAM, ddlMondayPM, tdMondayTitle));

    myDays.Add(new WhatsMyDay(
            DayOfWeek.Tuesday, ddlTuesdayAM, ddlTuesdayPM, tdTuesdayTitle));

    foreach (WhatsMyDay dayo in myDays)
    {
        dayo.ShowHideInterface(days.Contains(dayo.Day));
    }
}