public class Program
    {
public static void Main(string[] args)
        {
//创建一个HashTable
            Hashtable openWith = new Hashtable();

//为HashTable添加元素，不能有重复的key,但可以有重复的值
            openWith.Add("txt", "notepad.exe");
            openWith.Add("bmp", "paint.exe");
            openWith.Add("dib", "paint.exe");
            openWith.Add("rtf", "wordpad.exe");



//添加重复的key，会抛出异常
            try
            {
                openWith.Add("txt", "winword.exe");
            }
catch
            {
                Console.WriteLine("An element with Key = \"txt\" already exists.");
            }

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

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

//以赋值的方式，创建一个新元素
            openWith["doc"] = "winword.exe";

//如果HashTable中不包含该元素，将抛出异常(经测试这里不抛出异常)
//原因（如果未找到指定的键，尝试获取它将返回 空引用（在 Visual Basic 中为 Nothing），尝试设置它将使用指定的键创建新元素。 ）
            try
            {
                Console.WriteLine("For key = \"tif\", value = {0}.", openWith["tif"]);
            }
catch
            {
                Console.WriteLine("Key = \"tif\" is not found.");
            }

//判断是否包含特定的key
            if (!openWith.ContainsKey("ht"))
            {
                openWith.Add("ht", "hypertrm.exe");
                Console.WriteLine("Value added for key = \"ht\": {0}", openWith["ht"]);
            }

//遍历HashTable
            Console.WriteLine();
foreach (DictionaryEntry de in openWith)
            {
                Console.WriteLine("Key = {0}, Value = {1}", de.Key, de.Value);
            }

// 获取HashTable中值的集合
            ICollection valueColl = openWith.Values;


            Console.WriteLine();
foreach (string s in valueColl)
            {
                Console.WriteLine("Value = {0}", s);
            }

// 获取HashTable中键的集合
            ICollection keyColl = openWith.Keys;


            Console.WriteLine();
foreach (string s in keyColl)
            {
                Console.WriteLine("Key = {0}", s);
            }


            Console.WriteLine("\nRemove(\"doc\")");
//移除指定的元素
            openWith.Remove("doc");

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


            Hashtable mySourceHT = new Hashtable();
            mySourceHT.Add("A", "valueA");
            mySourceHT.Add("B", "valueB");

// 创建一个字符串数组
            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";

// 遍历数组的值
            Console.WriteLine("The target Array contains the following before:");
            PrintValues(myTargetArray, ' ');

//将hashtable中的key复制到数组中
            Console.WriteLine("After copying the keys, starting at index 6:");
            mySourceHT.Keys.CopyTo(myTargetArray, 6);


            PrintValues(myTargetArray, ' ');

//将hashtable中的Value复制到数组中
            Console.WriteLine("After copying the values, starting at index 6:");
            mySourceHT.Values.CopyTo(myTargetArray, 6);

            PrintValues(myTargetArray, ' ');

            Console.Read();
        }

//遍历数据方法
        public static void PrintValues(String[] myArr, char mySeparator)
        {
for (int i = 0; i < myArr.Length; i++)
                Console.Write("{0}{1}", mySeparator, myArr[i]);
            Console.WriteLine();
        }

    }