关闭.NETCore3.1中的C#套接字的正确方法是什么？

问题

我正在尝试处理我的应用程序的断开连接，无论我尝试了什么方法都失败了，我尝试从服务器端断开连接，我尝试从客户端断开连接，但两端都有问题，我在这里试图实现的是通过QUIT命令断开应用程序的连接，而不必在抛出异常时从close图标关闭它

client.cs

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

namespace MessengerConsole
{
class Client
{
    static string username;
    static int port = 8888;
    static IPAddress clientIP;
    static Socket serverSocket;
    static Thread processThread;
    static bool connected = false;

    static string GetIp()
    {
        Console.WriteLine("Type the server ip:");
        String clientIP = Console.ReadLine();
        Console.WriteLine("Client IP: " + clientIP);
        //return clientIP;
        //temp solution
        return "192.168.0.106";
    }

    static void printSession()
    {
        Console.Clear();
        Console.WriteLine("//=====================================================");
        Console.WriteLine("//                       Session Details               ");
        Console.WriteLine("//                    =====================");
        Console.WriteLine("//                    IP: " + clientIP + "\n//                    Time: " + DateTime.Now);
        Console.WriteLine("//=====================================================");
    }
    static void clientReceiver()
    {
        while (true)
        {
            Thread.Sleep(500);
            byte[] buffer = new byte[300];
            int rece = serverSocket.Receive(buffer, 0, buffer.Length, 0);
            Array.Resize(ref buffer, rece);
            if (connected == false)
            {
                Console.WriteLine("[" + DateTime.Now.ToString() + "] " + Encoding.Default.GetString(buffer) + " Connected!");
                connected = true;
            }

            else
            {

                if (Encoding.Default.GetString(buffer) == "QUIT")
                {
                    //Quit
                    Console.WriteLine("Server Shutdown");
                    serverSocket.Shutdown(SocketShutdown.Both);
                    serverSocket.Close();
                   
                }
                else
                {
                    Console.WriteLine("[" + DateTime.Now.ToString() + "] " + Encoding.Default.GetString(buffer));
                }

            }
        }
    }



    public static void StartClient()
    {
        processThread = new Thread(clientReceiver);
        Console.WriteLine("Please enter your name");
        username = Console.ReadLine();
        clientIP = IPAddress.Parse(GetIp());  //Returns IP from GetIP()
        Console.WriteLine("Please enter HostPort");
        //string portString = Console.ReadLine();
        //temp port
        string portString = "80";
        try
        {
            port = Convert.ToInt32(portString);
        }
        catch
        {
            port = 8888;
        }
        try
        {

            serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            serverSocket.Connect(new IPEndPoint(clientIP, port));
            processThread.Start();
            byte[] name = Encoding.Default.GetBytes(username);
            
            //Send Name
            serverSocket.Send(name);
           // byte[] data = Encoding.Default.GetBytes("<" + username + "> Connected");
            //serverSocket.Send(data, 0, data.Length, 0);
            printSession();
            while (serverSocket.Connected)
            {
                //byte[] sdata = Encoding.Default.GetBytes("<" + username + ">" + Console.ReadLine());
                byte[] sdata = Encoding.Default.GetBytes(Console.ReadLine());
                if(Encoding.Default.GetString(sdata) == "QUIT")
                {
                    serverSocket.Send(sdata, sdata.Length, 0);
                    serverSocket.Shutdown(SocketShutdown.Both);
                    serverSocket.Disconnect(true);
                    serverSocket.Close();
                }

                else
                {
                    serverSocket.Send(sdata, 0, sdata.Length, 0);
                }

            }
        }
        catch (Exception e)
        {
            Console.ForegroundColor = ConsoleColor.Red;
            Console.WriteLine(e.Message);
            Console.ForegroundColor = ConsoleColor.White;
        }

    }
}
}

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

namespace MessengerConsole
{
class Server
{

    //Server Socket
    static Socket serverSocket;
    //Client Socket
    static Socket clientSocket;

    //Other Variables
    static int port = 8888;
    static IPAddress serverIP;
    static Thread processThread;
    static string username;
    static bool connected = false;
    //Function returns IP Address
    static string GetIp()
    {
        //Computer Name
        string hostname = Dns.GetHostName();

        /*The IPHostEntry class associates a Domain Name System (DNS) host name with an array of aliases and 
         * an array of matching IP addresses.
         */
        IPHostEntry ipentry = Dns.GetHostEntry(hostname);

        //The Address
        IPAddress[] ipAddress = ipentry.AddressList;

        return ipAddress[ipAddress.Length - 1].ToString();
    }

    static void printSession()
    {
        Console.Clear();
        Console.WriteLine("//=====================================================");
        Console.WriteLine("//                       Session Details               ");
        Console.WriteLine("//                    =====================");
        Console.WriteLine("//                    You are hosting the server");
        Console.WriteLine("//                    Time: " + DateTime.Now);
        Console.WriteLine("//=====================================================");
    }
    //Receive
    static void serverReciever()
    {
        while (true)
        {
            Thread.Sleep(500);
            byte[] buffer = new byte[300];
            int rece = clientSocket.Receive(buffer, 0, buffer.Length, 0);
            Array.Resize(ref buffer, rece);

            if (connected == false)
            {
                Console.WriteLine("[" + DateTime.Now.ToString() + "] " + Encoding.Default.GetString(buffer) + " Connected!");
                connected = true;
            }

            else
            {
                if(Encoding.Default.GetString(buffer) == "QUIT")
                {
                    //Quit
                    Console.WriteLine("Client disconnected from the chat");
                    clientSocket.Shutdown(SocketShutdown.Both);
                    clientSocket.Close();
                }
                else
                {
                    Console.WriteLine("[" + DateTime.Now.ToString() + "] " + Encoding.Default.GetString(buffer));
                }

            }
        }
    }



    public static void StartServer()
    {
        //Thread
        processThread = new Thread(serverReciever);

        //Display
        Console.WriteLine("Your Local Ip is " + GetIp());
        Console.WriteLine("Please enter your name");
        username = Console.ReadLine();
        Console.WriteLine("Please enter HostPort");
        //  string portString = Console.ReadLine();
        //temp solution
        string portString = "80";
        try
        {
            port = Convert.ToInt32(portString);
        }
        catch
        {
            port = 8888;
        }

        try
        {
            //GetIp returns string
            serverIP = IPAddress.Parse(GetIp());
            //TCP Socket
            serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            serverSocket.Bind(new IPEndPoint(serverIP, port));
            serverSocket.Listen(0);

            //Server Socket listening for client requests
            clientSocket = serverSocket.Accept();
            printSession();
            processThread.Start();
            byte[] name = Encoding.Default.GetBytes(username);
            clientSocket.Send(name);
            while (true)
            {
                byte[] sdata = Encoding.Default.GetBytes(Console.ReadLine());
                clientSocket.Send(sdata, 0, sdata.Length, 0);
            }
        }
        catch
        {
            Console.ForegroundColor = ConsoleColor.Red;
            Console.WriteLine("Server already open!");
            Console.ForegroundColor = ConsoleColor.White;
        }
    }
}
}

这是我收到的错误

未处理的异常。System.ObjectDisposedException:无法访问已处置的对象。对象名称：“System.Net.Sockets.Socket”。在MessengerConsole.Client.clientReceiver（）的System.Net.Sockets.Socket.Receive（Byte[]buffer，Int32 offset，Int32 size，SocketFlags，SocketFlags，SocketError&errorCode）的System.Net.Sockets.Socket.Receive（Byte[]buffer，Int32 offset，Int32 size，SocketFlags，SocketFlags）中在C:\Users\Messenger控制台Appv2\Messenger控制台\Client.cs中：System.Threading.ThreadHelper.ThreadStart\u上下文（对象状态）的第42行，位于System.Threading.ExecutionContext.RunInternal（ExecutionContext ExecutionContext，ContextCallback回调，对象状态）---在System.Threading.ThreadHelper.ThreadStart（）上的System.Threading.ExecutionContext.RunInternal（ExecutionContext ExecutionContext，ContextCallback回调，对象状态）上引发异常的上一个位置的堆栈结束跟踪

我尝试使用Socket.Disconnect（）、Socket.Close（）、Socket.Dispose（），所有这些方法都会产生相同的结果

编辑：

在中添加

return

if(Encoding.Default.GetString(sdata) == "QUIT")
            {
                serverSocket.Send(sdata, sdata.Length, 0);
                serverSocket.Shutdown(SocketShutdown.Both);
                serverSocket.Close();
                return;
            }

结果服务器端没有错误，但客户端仍然抛出正在访问的已释放对象的异常

未处理的异常。System.ObjectDisposedException:无法访问已处置的对象。 对象名称：“System.Net.Sockets.Socket”。 位于System.Net.Sockets.Socket.Receive（字节[]缓冲区、Int32偏移量、Int32大小、SocketFlags、SocketError和errorCode） 位于System.Net.Sockets.Socket.Receive（字节[]缓冲区、Int32偏移量、Int32大小、SocketFlags和SocketFlags） 在C:\Users\Messenger ConsoleEAppv2\Messenger Console\Client.cs中的Messenger Console.Client.clientReceiver（）处：第44行 位于System.Threading.ThreadHelper.ThreadStart\u上下文（对象状态） 位于System.Threading.ExecutionContext.RunInternal（ExecutionContext ExecutionContext，ContextCallback回调，对象状态） ---来自引发异常的上一个位置的堆栈结束跟踪--- 位于System.Threading.ExecutionContext.RunInternal（ExecutionContext ExecutionContext，ContextCallback回调，对象状态） 位于System.Threading.ThreadHelper.ThreadStart（）处

---

在与

QUIT

相关的所有代码位置中，您只能关闭和处理套接字，而不能从服务于此套接字的无限循环返回。我认为在下一次迭代中，当对disposed socket上的

Connected

属性求值时，会抛出此堆栈。请尝试在关闭socket后添加

return

语句。

当我在serverSocket.close（）下面添加“return”时，您在下一次迭代中抛出的堆栈是正确的；它工作得很好，但客户端仍有一个错误。receiver（）仍在等待从服务器接收数据，并且再次抛出相同的异常（我将在回答中编辑它）。您正在使用

SocketShutdown。两者都是
，这是优雅地停止网络对话的一种不好的方式。在这里检查答案也许会有帮助。或者您可以在try catch块中包装套接字操作，catch
ObjectDisposedException
并在那里添加
return
，以静默方式放弃异常。ObjectDisposedException是一个临时修复，我将您的解释标记为答案