Hashtable
在System.Collection是命名空间李Hashtable是程序员经常用到的类，它以快速检索著称，是研发人员开发当中不可缺少的利器。
Hashtable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的键必须是唯一的，没有有效的排序，他进行的是内在的排序。
Hashtable有以下4中遍历方式：
1、以string对象为键值遍历哈希表。
2、以自定义对象为键值遍历哈希表。
3、以DictionaryEntry对象为键值遍历哈希表。
4、通过继承IDictionaryEnumerator接口的对象来遍历哈希表。
using System;using System.Collections;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ConsoleApp1{class Program{class Person{private int age;public int Age{get { return age; }set { age = value; }}private string name;public string Name{get { return name; }set { name = value; }}private string email;public string Email{get { return email; }set { email = value; }}}static void Main(string[] args){var a = new Person{Age = 34,Name = "Jacky",Email = "Jacky@"};var b = new Person{Age = 23,Name = "Ajay",Email = "Ajay@"};var c = new Person{Age = 12,Name = "Bill",Email = "Bill@"};var d = new Person{Age = 23,Name = "Gace",Email = "Gace@"};var e = new Person{Age = 45,Name = "Jim",Email = "Jim@"};var ht = new Hashtable{{ "1", a },{ "2", b },{ "3", c },{ "4", d },{ "5", e }};Console.WriteLine("请输入你的查询的用户名:");var strName = Console.ReadLine();//第一种方法foreach (string item in ht.Keys){var p = (Person)ht[item];if (strName == p.Name){Console.WriteLine("查询后的结果是:" + p.Name + "\t" + p.Email + "\t" + p.Age);}}Console.WriteLine("华丽的分割线=========================================================");//第二种方法foreach (Person item in ht.Values){if (item.Name == strName){Console.WriteLine("查询后的结果是:" + item.Name + "\t" + item.Email + "\t" + item.Age);}}Console.WriteLine("华丽的分割线=========================================================");//第三种方法foreach (DictionaryEntry item in ht){if (strName == ((Person)item.Value).Name){Console.WriteLine("查询后的结果是:" + ((Person)item.Value).Name + "\t" + ((Person)item.Value).Email + "\t" + ((Person)item.Value).Age);}}Console.WriteLine("华丽的分割线=========================================================");//第四种方法IDictionaryEnumerator id = ht.GetEnumerator();while (id.MoveNext()){Person p = (Person)ht[id.Key];if (p.Name == strName){Console.WriteLine("查询后的结果是:" + p.Name + "\t" + p.Email + "\t" + p.Age);}}Console.ReadKey();}}}
