ASP.NET添加日期，按降序排列

 List<string> dateList = new List<string>();

 if (Request.QueryString["DateTime"] != null)

 {

     dateList.Add(Request.QueryString["DateTime"].ToString());

 }

 else

 {

     for (int i = -10; i < 1; i++)

     {

         dateList.Add(DateTime.Now.AddDays(i).ToString("yyyyMMdd"));

     }

 }

 // 直接降序排序

 dateList.Sort((a, b) => b.CompareTo(a));

 this.DropDownList_Day.DataSource = dateList;

 this.DropDownList_Day.DataBind();

 this.DropDownList_Day.SelectedValue = DateTime.Now.ToString("yyyyMMdd");