c# - 无法通过 TCP 发送或接收消息

Question

我不断得到:

A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll System.Net.Sockets.SocketException (0x80004005): No connection could be made because the target machine actively refused it 911.00.00.666:13000

即使在我允许该应用程序通过 Windows 防火墙之后。我还尝试了端口 80、8080 和 13000。

为什么总是这样？我该如何解决？

我正在学习本教程:http://msdn.microsoft.com/en-us/library/system.net.sockets.tcpclient(v=vs.110).aspx#Y2523

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Sockets;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace TCPTestClient
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        String msgToSend = "Hello, dude.";

        private void button_Click_1(object sender, RoutedEventArgs e)
        {
            try
            {
                Int32 port = 13000;

                TcpClient client = new TcpClient("localhost", port);

                Byte[] data = System.Text.Encoding.ASCII.GetBytes(msgToSend);

                NetworkStream stream = client.GetStream();
                stream.Write(data, 0, data.Length);

                Console.WriteLine("Send: {0}", msgToSend);

                data = new Byte[256];

                String response = String.Empty;

                Int32 bytes = stream.Read(data, 0, data.Length);
                response = System.Text.Encoding.ASCII.GetString(data, 0, bytes);
                Console.WriteLine("Received: {0}", response);

                title.Text = response;

                stream.Close();
                client.Close();
            }
            catch (ArgumentNullException ex)
            {
                Console.WriteLine(ex);
            }
            catch (SocketException s)
            {
                Console.WriteLine(s);
            }

            Console.WriteLine("Done");
            // All done.
        }
    }
}

Answer 1

链接的文档假设有一个服务器正在运行并接受相关端口上的连接。您的代码只是一个客户端。它需要一个服务器才能连接。

参见 Socket有关如何运行服务器的信息的类。