C# Hashtable 正序和逆序排序

注意：Hashtable 按鍵的正序排列鍵/值對，預設情況下的遍曆GetValues是逆序遍曆。

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;

namespace HashtableSort
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("+++++++++++對HashTable排序測試+++++++++++");
            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();
        }
        //添加鍵/值對
        public void Add(object key, object value)
        {
            htb.Add(key, value);
            Console.WriteLine(string.Format("向Hashtable中添加了/t鍵{0}，值{1}", key, value));
        }
        //遍曆Hsahtbale
        public void GetValues()
        {
            Console.WriteLine("+++++++++++遍曆Hsahtbale開始+++++++++++");
            foreach(DictionaryEntry de in htb)
            {
                Console.WriteLine("當前Hashtable中的鍵/值對：/t鍵：{0},值：{1}",de.Key,de.Value);
            }
            Console.WriteLine("+++++++++++遍曆Hsahtbale結束+++++++++++");
        }
        //得到Hashtable資訊
        public void GetInfo()
        {
            Console.WriteLine("Hashtable中有鍵/值對{0}對", htb.Count);
        }
        //對HashTable排序
        public void AscSort()
        {
            Console.WriteLine("+++++++++++對HashTable正序排序開始+++++++++++");
            ArrayList arrList = new ArrayList(htb.Keys);
            arrList.Sort();
            //for (int i = 0; i < arrList.Count; i++)
            //{
            //    Console.WriteLine("/t鍵{0}", arrList[i]);
            //}
            for (int i = 0; i < arrList.Count; i++)
            {
                Console.WriteLine(string.Format("/t鍵：{0}的值是：{1}", arrList[i], htb[arrList[i]]));
            }
            Console.WriteLine("+++++++++++對HashTable正序排序結束+++++++++++");
        }
        public void DescSort()
        {
            Console.WriteLine("+++++++++++對HashTable逆序排序開始+++++++++++");
            ArrayList arrList = new ArrayList(htb.Keys);
            arrList.Sort();
            //for (int i = 0; i < arrList.Count; i++)
            //{
            //    Console.WriteLine("/t鍵{0}", arrList[i]);
            //}
            for (int i = arrList.Count-1; i >= 0; i--)
            {
                Console.WriteLine(string.Format("/t鍵：{0}的值是：{1}", arrList[i], htb[arrList[i]]));
            }
            Console.WriteLine("+++++++++++對HashTable逆序排序結束+++++++++++");
        }
    }
}

有特點的幾處：arrList[i], htb[arrList[i]]