Hashtable 数据遍历的几种方式

Hashtable 在集合中称为键值对，它的每一个元素的类型是 DictionaryEntry,由于Hashtable对象的键和值都是Object类型，决定了它可以放任何类型的数据，

下面我就把Hashtable对象中放置定义的一个类的几个对象。

创建的类如下：

//代码
static void Main(string[] args)
{
    Person person1 = new Person();
    person1.Age = 34;
    person1.Name = "Jacky";
    person1.Email = "Jacky@gmail.com";
    Person person2 = new Person();
    person2.Age = 23;
    person2.Name = "Ajay";
    person2.Email = "Ajay@gmail.com";
    Person person3 = new Person();
    person3.Age = 12;
    person3.Name = "Bill";
    person3.Email = "Bill@gmail.com";
    Person person4 = new Person();
    person4.Age = 23;
    person4.Name = "Gace";
    person4.Email = "Gace@gmail.com";
    Person person5 = new Person();
    person5.Age = 45;
    person5.Name = "Jim";
    person5.Email = "Jim@gmail.com";
    Hashtable ht = new Hashtable();
    ht.Add("1", person1);
    ht.Add("2", person2);
    ht.Add("3", person3);
    ht.Add("4", person4);
    ht.Add("5", person5);
    Console.WriteLine("请输入你的查询的用户名:");
    string strName = Console.ReadLine();
    //第一种方法
    foreach (string item in ht.Keys)
    {
        Person 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);
        }
    }

    //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);
        }
    }

    //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)."\t" + ((Person)item.Value).Age);
        }
    }
    //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);
        }
    }

}