C# Hashtable

using System;
using System.Collections;//使用Hashtable时，必须引入这个命名空间 

namespace ConsoleTest
{
    class HashtableTest
    {
        public static void HashtableTestMain()
        {
            // 创建一个Hashtable实例
            Hashtable ht = new Hashtable();

            // 添加key-value键值对
            ht.Add("A", "1");
            ht.Add("B", "2");
            ht.Add("C", "3");
            ht.Add("D", "4");

            // 遍历哈希表只能用foreach来遍历,因为Hashtable不能用索引访问
            // 遍历key
            foreach (Object item in ht.Keys)
            {
                Console.WriteLine("Key : {0} ;", (string)item);
            }
            // 遍历value
            foreach (Object item in ht.Values)
            {
                Console.WriteLine("Value : {0} ;", (string)item);
            }
            //遍历
            foreach (DictionaryEntry de in ht)
            {
                Console.WriteLine("Key : {0} ; Value : {1}.", de.Key, de.Value);
            }

            // 哈希表排序
            ArrayList list = new ArrayList(ht.Keys);
            list.Sort();
            foreach (string key in list)
            {
                Console.WriteLine("Key : {0} ; Value : {1}.", key, ht[key]);
            }

            // 赋值
            ht["A"] = "你好";

            // 判断哈希表是否包含特定键,其返回值为true或false
            if (ht.Contains("A"))
            {
                Console.WriteLine("Key : {0} ; Value : {1}.", "A", ht["A"]);
            }

            // 移除一个key-value键值对
            ht.Remove("C");

            // 遍历哈希表
            IDictionaryEnumerator myEnumerator = ht.GetEnumerator();
            while (myEnumerator.MoveNext())
            {
                Console.WriteLine("Key : {0} ; Value : {1}.", myEnumerator.Key, ht[myEnumerator.Key]);
            }

            // 复制
            Hashtable ht2 = ht.Clone() as Hashtable;
            ht2["A"] = "世界";
            ht["B"] = "晚安";
            ht.Add("E", "5");

            // 将HashTable中键或值列表复制到数组的方法
            String[] myTargetArray = new String[15];
            myTargetArray[0] = "The";
            myTargetArray[1] = "quick";
            myTargetArray[2] = "brown";
            myTargetArray[3] = "fox";
            myTargetArray[4] = "jumped";
            myTargetArray[5] = "over";
            myTargetArray[6] = "the";
            myTargetArray[7] = "lazy";
            myTargetArray[8] = "dog";
            ht.Keys.CopyTo(myTargetArray, 6);  //赋值键到数组中，从第7位起覆盖。
            ht.Values.CopyTo(myTargetArray, 10);//赋值值到数组中，从第7位起覆盖。

            // 移除所有元素
            ht.Clear();
            Console.ReadKey();
        }
    }
}