Hashtable与Dictionary比较

　　项目需要存储Tcp连接对象，考虑使用Hashtable或者Dictionary存储。Hashtable在查询方面有优势，Dictionary在确定类型下不需要拆箱与装箱有优势。于是，写了个demo对两个存储对象进行了插入、查询、删除、遍历的速度比较。

        static Hashtable hashtable = new Hashtable();
        static Dictionary<string, ConnectedClient> keyValuePairs = new Dictionary<string, ConnectedClient>();

        static void Init()
        {
            Stopwatch stopwatch = new Stopwatch();
            stopwatch.Start();
            for(int i = 0; i < 100000; i++)
            {
                ConnectedClient connectedClient = new ConnectedClient(new TcpClient());
                hashtable.Add(i.ToString(),connectedClient);
            }
            stopwatch.Stop();
            Console.WriteLine(string.Format("Hashtable插入100000耗时{0}。", stopwatch.ElapsedTicks));
            stopwatch.Restart();
            for (int i = 0; i < 100000; i++)
            {
                ConnectedClient connectedClient = new ConnectedClient(new TcpClient());
                keyValuePairs.Add(i.ToString(), connectedClient);
            }
            stopwatch.Stop();
            Console.WriteLine(string.Format("Dictionary插入100000耗时{0}。", stopwatch.ElapsedTicks));

            stopwatch.Restart();
            var result = (ConnectedClient)hashtable["70000"];
            stopwatch.Stop();
            Console.WriteLine(string.Format("Hashtable搜索一条耗时{0}。", stopwatch.ElapsedTicks));

            stopwatch.Restart();
            result = keyValuePairs["70000"];
            stopwatch.Stop();
            Console.WriteLine(string.Format("Dictionary搜索一条耗时{0}。", stopwatch.ElapsedTicks));

            stopwatch.Restart();
            hashtable.Add("9000000", new ConnectedClient(new TcpClient())); ;
            stopwatch.Stop();
            Console.WriteLine(string.Format("Hashtable插入一条耗时{0}。", stopwatch.ElapsedTicks));

            stopwatch.Restart();
            keyValuePairs.Add("9000000", new ConnectedClient(new TcpClient())); ;
            stopwatch.Stop();
            Console.WriteLine(string.Format("Dictionary插入一条耗时{0}。", stopwatch.ElapsedTicks));

            stopwatch.Restart();
            hashtable.Remove("9000000");;
            stopwatch.Stop();
            Console.WriteLine(string.Format("Hashtable删除一条耗时{0}。", stopwatch.ElapsedTicks));

            stopwatch.Restart();
            keyValuePairs.Remove("9000000");;
            stopwatch.Stop();
            Console.WriteLine(string.Format("Dictionary删除一条耗时{0}。", stopwatch.ElapsedTicks));

            stopwatch.Restart();
            foreach (var key in hashtable.Keys)
            {
                ((ConnectedClient)hashtable[key]).outCount--;
            }
            Console.WriteLine(string.Format("Hashtable遍历耗时{0}。", stopwatch.ElapsedTicks));
            stopwatch.Stop();

            stopwatch.Restart();
            foreach (var key in keyValuePairs.Keys)
            {
                keyValuePairs[key].outCount--;
            }
            Console.WriteLine(string.Format("Dictionary遍历耗时{0}。", stopwatch.ElapsedTicks));
            stopwatch.Stop();

            Console.ReadLine();
        }