C# Hashtable 正序和逆序排序

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本文固定链接：http://www.verydemo.com/demo_c92_i266864.html

注意：Hashtable 按键的正序排列键/值对，默认情况下的遍历GetValues是逆序遍历。

using System;

using System.Collections.Generic;

using System.Text;

using System.Collections;

namespace HashtableSort

{

    class Program

    {

        static void Main(string[] args)

        {

            Console.WriteLine("+++++++++++对HashTable排序测试+++++++++++");

            HashTable htb = new HashTable();

            htb.Add(1, "1");

            htb.Add(3, "3");

            htb.Add(0, "0");

            htb.Add(2, "2");

            htb.Add(7, "7");

            htb.Add(6, "6");

            htb.Add(8, "8");

            htb.Add(10, "10");

            htb.Add(9, "9");

            htb.Add(11, "11");

            htb.GetValues();

            htb.GetInfo();

            htb.AscSort();

            htb.DescSort();

        }

    }

    class HashTable

    {

        Hashtable htb;

        public HashTable()

        {

            htb = new Hashtable();

        }

        //添加键/值对

        public void Add(object key, object value)

        {

            htb.Add(key, value);

            Console.WriteLine(string.Format("向Hashtable中添加了/t键{0}，值{1}", key, value));

        }

        //遍历Hsahtbale

        public void GetValues()

        {

            Console.WriteLine("+++++++++++遍历Hsahtbale开始+++++++++++");

            foreach(DictionaryEntry de in htb)

            {

                Console.WriteLine("当前Hashtable中的键/值对：/t键：{0},值：{1}",de.Key,de.Value);

            }

            Console.WriteLine("+++++++++++遍历Hsahtbale结束+++++++++++");

        }

        //得到Hashtable信息

        public void GetInfo()

        {

            Console.WriteLine("Hashtable中有键/值对{0}对", htb.Count);

        }

        //对HashTable排序

        public void AscSort()

        {

            Console.WriteLine("+++++++++++对HashTable正序排序开始+++++++++++");

            ArrayList arrList = new ArrayList(htb.Keys);

            arrList.Sort();

            //for (int i = 0; i < arrList.Count; i++)

            //{

            //    Console.WriteLine("/t键{0}", arrList[i]);

            //}

            for (int i = 0; i < arrList.Count; i++)

            {

                Console.WriteLine(string.Format("/t键：{0}的值是：{1}", arrList[i], htb[arrList[i]]));

            }

            Console.WriteLine("+++++++++++对HashTable正序排序结束+++++++++++");

        }

        public void DescSort()

        {

            Console.WriteLine("+++++++++++对HashTable逆序排序开始+++++++++++");

            ArrayList arrList = new ArrayList(htb.Keys);

            arrList.Sort();

            //for (int i = 0; i < arrList.Count; i++)

            //{

            //    Console.WriteLine("/t键{0}", arrList[i]);

            //}

            for (int i = arrList.Count-1; i >= 0; i--)

            {

                Console.WriteLine(string.Format("/t键：{0}的值是：{1}", arrList[i], htb[arrList[i]]));

            }

            Console.WriteLine("+++++++++++对HashTable逆序排序结束+++++++++++");

        }
    }

}

有特点的几处：arrList[i], htb[arrList[i]]