这是不是重复命名？

Question

一段网络应用小程序如下：
    class Program
    {
        const int portNo = 500;
        static void Main(string[] args)
        {
            System.Net.IPAddress localAdd = System.Net.IPAddress.Parse("127.0.0.1");
            TcpListener listener = new TcpListener(localAdd, portNo);
            listener.Start();
            while (true)
            {
                ChatClient user = new ChatClient(listener.AcceptTcpClient());
            }
        }
    }
我觉得奇怪，在while无限循环里，我理解的是user不是被重复命名了么？ChatClient user，重复命名。
那位高手帮忙给解释解释。

Answer 1

我把完整代码贴出来：using System;
using System.Collections.Generic;
using System.Text;using System.Net.Sockets;namespace server_CS
{
    class Program
    {
        const int portNo = 500;
        static void Main(string[] args)
        {
            System.Net.IPAddress localAdd = System.Net.IPAddress.Parse("127.0.0.1");
            TcpListener listener = new TcpListener(localAdd, portNo);
            listener.Start();
            while (true)
            {
                ChatClient user = new ChatClient(listener.AcceptTcpClient());
            }
        }
    }
}using System;
using System.Collections.Generic;
using System.Text;using System.Net.Sockets;
using System.Collections;namespace server_CS
{
    class ChatClient
    {
        public static Hashtable AllClients = 
            new Hashtable();
        private TcpClient _client;
        private string _clientIP;
        private string _ClientNick;
        private byte[] data;
        private bool ReceiveNick = true;        public ChatClient(TcpClient client)
        {
            _client = client;
            _clientIP = client.Client.RemoteEndPoint.ToString();
            AllClients.Add(_clientIP, this);
            
            data = new byte[_client.ReceiveBufferSize];
            _client.GetStream().BeginRead(data, 0, System.Convert.ToInt32(_client.ReceiveBufferSize), ReceiveMessage, null);           
        }        public void SendMessage(string message)
        {
            try
            {
                System.Net.Sockets.NetworkStream ns;
                lock (_client.GetStream())
                {
                    ns = _client.GetStream();
                }
                byte[] bytesToSend = System.Text.Encoding.ASCII.GetBytes(message);
                ns.Write(bytesToSend, 0, bytesToSend.Length);
                ns.Flush();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
        }        public void ReceiveMessage(IAsyncResult ar)
        {
            int bytesRead;
            try
            {
                lock (_client.GetStream())
                {
                    bytesRead = _client.GetStream().EndRead(ar);
                }
                if (bytesRead < 1)
                {
                    AllClients.Remove(_clientIP);
                    Broadcast(_ClientNick + " has left the chat.");
                    return;
                }
                else
                {
                    string messageReceived = System.Text.Encoding.ASCII.GetString(data, 0, bytesRead);
                    if (ReceiveNick)
                    {
                        _ClientNick = messageReceived;
                        Broadcast(_ClientNick + " has joined the chat.");
                        ReceiveNick = false;
                    }
                    else
                    {
                        Broadcast(_ClientNick + ">" + messageReceived);
                    }
                }
                lock (_client.GetStream())
                {
                    _client.GetStream().BeginRead(data, 0, System.Convert.ToInt32(_client.ReceiveBufferSize),ReceiveMessage, null);
                }
            }
            catch (Exception ex)
            {
                AllClients.Remove(_clientIP);
                Broadcast(_ClientNick + " has left the chat.");
            }
        }
        public void Broadcast(string message)
        {
            Console.WriteLine(message);
            foreach (DictionaryEntry c in AllClients)
            {
                ((ChatClient)(c.Value)).SendMessage(message + Environment.NewLine);
            }
        }
    }
}

Answer 2

            while (true)
            {
                ChatClient user = new ChatClient(listener.AcceptTcpClient());
            }这应该不是重复命名，因为出了作用域就失效了。

Answer 3

没有重复,这个零时变量的作用域就是while{}里，用完就丢。所以没什么问题。
你理解成1个类里2个函数都包含变量xxx，但他们不重复，不冲突。其实是一样的道理

Answer 4

名称只不过是一个名字,代号(ID)唯一就行了,
每一个NEW的初始化都会生成新的对象

Answer 5

                ChatClient user = new ChatClient(listener.AcceptTcpClient());
每次while后,user都是一个新的.必须要重新定义并赋值.