C# SortedList类

using System;
using System.Collections;

namespace CollectionsApplication {

   class Program {

      static void Main(string[] args) {
         SortedList sl = new SortedList();

         sl.Add("001", "Zara Ali");
         sl.Add("002", "Abida Rehman");
         sl.Add("003", "Joe Holzner");
         sl.Add("004", "Mausam Benazir Nur");
         sl.Add("005", "M. Amlan");
         sl.Add("006", "M. Arif");
         sl.Add("007", "Ritesh Saikia");

         if (sl.ContainsValue("Nuha Ali")) {
            Console.WriteLine("This student name is already in the list");
         } else {
            sl.Add("008", "Nuha Ali");
         }

         // get a collection of the keys. 
         ICollection key = sl.Keys;

         foreach (string k in key) {
            Console.WriteLine(k + ": " + sl[k]);
         }
      }
   }
}