C# 错误 CS0246 找不到类型或命名空间名称“Socket”（您是否缺少 using 指令或程序集引用）

Question

I write a client-server program in C# to send words or libraries to client and to get their answer such as if they want to add new words or libraries to a dictionary or not. My problem is the libraries System.Net.Sockets and System.Net are not recognized or properly connected. Would you Plz help me with what is going wrong here?

here is my code:

using System;    
using System.Net;    
using System.Net.Sockets;    
using System.Text;    
using System.Threading;    

namespace Dictionary.Net.SocketWrappers    
{    
    public class ServerSocket
    {
        private Func<string, string> _getMessage;
        private Socket _socket;
        public readonly int backlog;
        public readonly Encoding encoding;
        public ServerSocket(int port, int backlog, Func<string, string> getMessage, Encoding encoding)
        {
            _socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            var iPEndPoint = new IPEndPoint(IPAddress.Any, port);
            _socket.Bind(iPEndPoint);
            this.backlog = backlog;
            this._getMessage = getMessage;
            this.encoding = encoding;
        }

        public void Run()
        {
            try
            {
                _socket.Listen(backlog);
            }
            catch (SocketException)
            {
                return;
            }
            while (true)
            {
                try
                {
                    var client = _socket.Accept();
                    if (client != null)
                        ThreadPool.QueueUserWorkItem(ClientThread, client);
                }
                catch (SocketException)
                {
                    continue;
                }
            }
        }

        private void ClientThread(object newClientObject)
        {
            var newClient = newClientObject as Socket;
            var clientSocket = new ClientSocket(newClient, encoding);
            bool IsListening = true;
            while (IsListening)
            {
                try
                {
                    var receivedData = clientSocket.Receive();
                    var dataToSend = _getMessage(receivedData);
                    clientSocket.Send(dataToSend);
                }
                catch (SocketException)
                {
                    IsListening = false;
                }
            }
        }
    }
}

Screenshot of all references which I have

Answer 1

As Patrick Hofman already answered, you're missing a reference to System.Net.Sockets .

You can use the Visual Studio Package Manager to get it from NuGet.

The window can be accessed over the menu with VIEW > Other Windows > Package Manager Console

In the console, you have to simple write your requested package.

So in your case write Install-Package System.Net.Sockets .