Hashtable 數據遍歷的幾種方式

Hashtable 在集合中稱為鍵值對，它的每一個元素的類型是 DictionaryEntry,由於Hashtable對象的鍵和值都是Object類型，決定了它可以放任何類型的數據，

下面我就把Hashtable對象中放置定義的一個類的幾個對象。

創建的類如下：

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; }
        }
    }

　　Hashtable的幾種遍歷方法如下：

代碼 
 static void Main(string[] args)
        {
            Person person1 = new Person();
            person1.Age = 34;
            person1.Name = "Jacky";
            person1.Email = "[e-mail]";
 
            Person person2 = new Person();
            person2.Age = 23;
            person2.Name = "Ajay";
            person2.Email = "[e-mail]";
 
            Person person3 = new Person();
            person3.Age = 12;
            person3.Name = "Bill";
            person3.Email = "[e-mail]";
 
            Person person4 = new Person();
            person4.Age = 23;
            person4.Name = "Gace";
            person4.Email = "[e-mail]";
 
            Person person5 = new Person();
            person5.Age = 45;
            person5.Name = "Jim";
            person5.Email = "[e-mail]";
 
            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("請輸入你的查詢的用戶名:");
            string strName = Console.ReadLine();
            //第一種方法
             foreach (string item in ht.Keys)
            {
                Person p = (Person)ht[item];
                if (strName == p.Name)
                {
                    Console.WriteLine("查詢后的結果是:" + p.Name + "\t" + p.Email + "\t" + p.Age);
                }
            }
 
 
 
            //第二種方法
             foreach (Person item in ht.Values)
            {
                if (item.Name == strName)
                {
                    Console.WriteLine("查詢后的結果是:" + item.Name + "\t" + item.Email + "\t" + item.Age);
                }
 
            }
            //第三種方法
             foreach (DictionaryEntry item in ht)
            {
                if (strName == ((Person)item.Value).Name)
                {
                    Console.WriteLine("查詢后的結果是:" + ((Person)item.Value).Name + "\t" + ((Person)item.Value).Email + "\t" + ((Person)item.Value).Age);
                }
            }
 
            //第四種方法
             IDictionaryEnumerator id = ht.GetEnumerator();
            while (id.MoveNext())
            {
             Person p =   (Person)ht[id.Key];
             if (p.Name == strName)
             {
                 Console.WriteLine("查詢后的結果是:" + p.Name + "\t" + p.Email + "\t" + p.Age);
             }
            }
 
        }