c# – 侦听和接受连接的简单Telnet控制台

我是Telnet和C#的新手,我正在尝试创建一个简单的控制台程序.我需要一个启动的TCP侦听器,侦听传入的网络连接并发回响应.我并不真正关心传入的消息,但我需要接受它,以便客户认为连接成功.此TCP侦听器将以“Hello”响应.
我只需要确保它干净地启动并正常关闭TCP侦听器而不会抛出任何异常.我需要使用“Telnet localhost 9090”连接到端口9090上笔记本电脑上的TCP侦听器.

你能帮我吗？

解决方法

使用 TCPListener类.该示例回应从第二组代码中提供的客户端发送给它的字符串,因此它发送响应Howdy.您可以在运行下面的客户端代码时对此进行测试,该代码调用Socket.Receive从服务器返回字符串：

using System;
using System.IO;
using System.Net;
using System.Net.sockets;
using System.Text;

namespace tcplistener
{
    class Program
    {
        static void Main(string[] args)
        {
             TcpListener server = null;
        try
        {
            Int32 port = 9090;
            IPAddress localAddr = IPAddress.Parse("127.0.0.1");

            server = new TcpListener(localAddr,port);

            // Start listening for client requests.
            server.Start();

            // Buffer for reading data
            Byte[] bytes = new Byte[256];
            String data = null;

            // Enter the listening loop. 
            while (true)
            {
                Console.Write("Waiting for a connection... ");

                // Perform a blocking call to accept requests. 
                // You Could also user server.AcceptSocket() here.
                TcpClient client = server.AcceptTcpClient();
                Console.WriteLine("Hello!");

                data = null;

                // Get a stream object for reading and writing
                NetworkStream stream = client.GetStream();

                int i;

                // Loop to receive all the data sent by the client. 
                while ((i = stream.Read(bytes,bytes.Length)) != 0)
                {
                    // Translate data bytes to a ASCII string.
                    data = System.Text.Encoding.ASCII.GetString(bytes,i);
                    Console.WriteLine("Received: {0}",data);

                    // Process the data sent by the client.
                    data = data.toupper();

                    byte[] msg = System.Text.Encoding.ASCII.GetBytes(data);

                    // Send back a response.
                    stream.Write(msg,msg.Length);
                    Console.WriteLine("Sent: {0}",data);
                }

                // Shutdown and end connection
                client.Close();
            }
        }
        catch (SocketException e)
        {
            Console.WriteLine("SocketException: {0}",e);
        }
        finally
        {
            // Stop listening for new clients.
            server.Stop();
        }


        Console.WriteLine("\nHit enter to continue...");
        Console.Read();

        }
    }
}

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.sockets;
using System.Text;
using System.Threading.Tasks;

namespace tcpconnect
{
    class Program
    {
        static void Main(string[] args)
        {
            Connect1("127.0.0.1",9090);

            Console.Read();
        }

        // Synchronous connect using IPAddress to resolve the  
        // host name. 
        public static void Connect1(string host,int port)
        {
            IPAddress[] IPs = Dns.GetHostAddresses(host);

            Socket s = new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);

            Console.WriteLine("Establishing Connection to {0}",host);
            s.Connect(IPs[0],port);

            byte[] howdyBytes = Encoding.ASCII.GetBytes("Howdy");
            s.Send(howdyBytes);
            byte[] buffer = new byte[50];
            s.Receive(buffer);
            Console.Write(Encoding.ASCII.GetString(buffer));
            Console.WriteLine("Connection established");
        }
    }
}