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

namespace HashtableExample
{
    class Program
    {
        static void Main(string[] args)
        {
            //创建一个新的hash表.表示键/值对的集合，这些键/值对根据键的哈希代码进行组织。
            Hashtable openWith = new Hashtable();

            //添加一些元素
            openWith.Add("txt", "notepad.exe");
            openWith.Add("bmp", "paint.exe");
            openWith.Add("dib", "paint.exe");
            openWith.Add("rtf", "wordpad.exe");

            //如果新添加的元素已经在表中，则抛出异常
            try
            {
                openWith.Add("txt", "winword.exe");
            }
            catch
            {
                Console.WriteLine("带有Key是 \"txt\" 的元素已经存在.");
            }

            Console.WriteLine("For key = \"rtf\", value = {0}.", openWith["rtf"]);

//---------------------------------------------------------------------------------------------------

            //openWith["rtf"] = "winword.exe";
           openWith["rtf"] = "测试1";
            Console.WriteLine("For key = \"rtf\", value = {0}.", openWith["rtf"]);

//---------------------------------------------------------------------------------------------------
            openWith["doc"] = "winword.exe";

            //如果寻找的不在表中，则抛出异常
            try
            {
                Console.WriteLine("For key = \"tif\", value = {0}.", openWith["tif"]);
            }
            catch
            {
                Console.WriteLine("Key = \"tif\" is not found.");
            }

            // 在插入之前，ContainsKey用来测试keys
            if (!openWith.ContainsKey("ht"))
            {
                openWith.Add("ht", "hypertrm.exe");
                Console.WriteLine("8888888888888Value added for key = \"ht\": {0}", openWith["ht"]);
            }

            // foreach枚举hash表的元素
            Console.WriteLine();
            foreach (DictionaryEntry de in openWith)
            {
                Console.WriteLine("555555555Key = {0}, Value = {1}", de.Key, de.Value);
            }

            // Values属性获取
            ICollection valueColl = openWith.Values;

            // ValueCollection的值输出
            Console.WriteLine();
            foreach (string s in valueColl)
            {
                Console.WriteLine("66666666Value = {0}", s);
            }

            ICollection keyColl = openWith.Keys;

            // ValueCollection的值输出
            Console.WriteLine();
            foreach (string s in keyColl)
            {
                Console.WriteLine("2222222222222Key = {0}", s);
            }

            // Remove方法删除key/value.
            Console.WriteLine("\nRemove(\"doc\")");

            Console.WriteLine("删除前 "+openWith["doc"]);
            openWith.Remove("doc");

            if (!openWith.ContainsKey("doc"))
            {
                Console.WriteLine("Key \"doc\" is not found.");
            }

            Console.Read();
        }
    }
}

评论