如何修复错误"通常只允许使用每个套接字地址(协议/网络地址/端口)"？

Question

我做了很多谷歌搜索,但我的问题没有太多运气.我是网络编程的新手并且正在努力学习,我试图建立一个简单的服务器和客户端进行通信(按照这里的在线教程 - > http://tech.pro/tutorial/704/csharp-tutorial- simple-threaded-tcp-server)

我遇到的问题是我一直得到异常"当尝试在服务器上启动TcpListener时,通常只允许使用每个套接字地址(协议/网络地址/端口)".

我已经尝试禁用我的防火墙,更改要使用的端口,移动变量但无效(客户端工作正常,但它显然无法找到服务器,因为我无法启动它).

我已经看到了描述Socket.Poll()使用的解决方案,但由于我只使用TcpListener对象,所以我不知道如何使用Poll函数.

我的代码:

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

namespace ServerTutorial {
class Server {
    private readonly Thread m_listenThread;

    public Server() {
        m_listenThread = new Thread(new ThreadStart(ListenForClients));
        m_listenThread.Start();
    }

    public void ListenForClients() {
        var listener = new TcpListener(IPAddress.Any, 3000);
        listener.Start();

        while (true) {
            //Blocks until a client has connected to the server
            TcpClient client = listener.AcceptTcpClient();

            //Send a message to the client
            var encoder = new ASCIIEncoding();
            NetworkStream clientStream = client.GetStream();
            byte[] buffer = encoder.GetBytes("Hello Client!");
            clientStream.Write(buffer, 0, buffer.Length);
            clientStream.Flush();

            //Create a thread to handle communication with the connected client
            var clientThread = new Thread(new ParameterizedThreadStart(HandleClient));
            clientThread.Start(client);
        }
    }

    private void HandleClient(object clientObj) { //Param thread start can only accept object types, hence the cast
        var client = (TcpClient) clientObj;
        NetworkStream clientStream = client.GetStream();

        var message = new byte[4096];

        while (true) {
            int bytesRead = 0;

            try {
                //Block until a client sends a message
                bytesRead = clientStream.Read(message, 0, 4096);
            } catch {
                //A socket error has occurred
                System.Diagnostics.Debug.WriteLine("A socket error has occured");
                break;
            }

            if (bytesRead == 0) {
                //The client has disconnected from the server
                System.Diagnostics.Debug.WriteLine("A client has disconnected from the server");
                client.Close();
                break;
            }

            //Message has been received
            var encoder = new ASCIIEncoding();
            System.Diagnostics.Debug.WriteLine(encoder.GetString(message, 0, bytesRead));
        }
    }
}
}

在我的主要方法中:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ServerTutorial {
class Program {
    static void Main(string[] args) {
        var server = new Server();
        server.ListenForClients();
    }
}
}

任何帮助都非常感谢!

Answer 1

ListenForClients被调用两次(在两个不同的线程上) - 一次来自构造函数,一次来自显式方法调用Main.当TcpListener尝试在同一端口上侦听的两个实例时,您会收到该错误.

Answer 2

您正在调试两次或更多次.所以应用程序可能一次运行更多.那么只会发生这个问题.您应该使用task-manager关闭所有调试应用程序,然后再次调试.