using System;

using System.Text;

using System.Windows;

using System.Threading;

using System.Net;

using System.Net.Sockets; 

namespace SocketBlockingInterrupt{

    public partial class MainWindow : Window

    {

        bool bIsExecute;

        TcpListener listener;//监听套接字

        SynchronizationContext synContext;

 

        public MainWindow()

        {

            InitializeComponent();

            synContext = SynchronizationContext.Current;

            btnStop.IsEnabled = false;

        }

 

        private void btnStart_Click(object sender, RoutedEventArgs e)

        {

            bIsExecute = true; //建立循环条件

            btnStart.IsEnabled = false;

            btnStop.IsEnabled = true;

 

            //开启监听线程

            Thread t = new Thread(new ThreadStart(ListenThread));

            t.IsBackground = true;

            t.Start();

        }

 

        void ListenThread()

        {

            IPEndPoint localEP = new IPEndPoint(IPAddress.Any, 9000);

            listener = new TcpListener(localEP);

            listener.Start();         //启动监听，非阻塞 

            synContext.Post(updateUI, "监听线程：正在监听中..."); 

            while (bIsExecute) //循环条件

            {

                byte[] recvBuff = new byte[512]; 

                //捕获异常，强行退出Accept阻塞

                try

                {

                    synContext.Post(updateUI, "监听线程：Accept正在阻塞中..."); 

                    TcpClient client = listener.AcceptTcpClient();     // 等待连接（阻塞）

                    synContext.Post(updateUI, "监听线程：收到连接请求，已退出Accept阻塞"); 

                    int recvByte = client.Client.Receive(recvBuff);// 建立连接

 

                    // 解析命令

                    byte[] buff = new byte[recvByte];

                    for (int i = 0; i < recvByte; i++ ) { buff[i] = recvBuff[i]; }

                    string exitByt = Encoding.ASCII.GetString(buff);

                    if (exitByt == "Exit")

                    {

                        synContext.Post(updateUI, "监听线程：收到数据" + exitByt);

                        break;

                    }

                }

                catch (SocketException ex)

                {

                    synContext.Post(updateUI, "监听线程：发生异常，Accept阻塞被强行退出：" + ex.Message);

                    break;

                }

            }

            synContext.Post(updateUI, "监听线程：已成功退出监听");

        }

 

        private void btnStop_Click(object sender, RoutedEventArgs e)

        {

            bIsExecute = false; //此处拆除循环条件 

            //方法1：直接停止监听套接字，引发异常从而强行使Accept退出阻塞。

            //---------------------------------------------

            //if (listener != null)

            //{

            //    listener.Stop();

            //}

            //--------------------------------------------- 

           

            //方法2：主动发送一条数据，使Accept自然地退出阻塞。

            //---------------------------------------------

            TcpClient tcpClient = new TcpClient();

            tcpClient.Connect("127.0.0.1",9000); 

            NetworkStream ns = tcpClient.GetStream();

            if (ns.CanWrite)

            {

                Byte[] sendBytes = Encoding.ASCII.GetBytes("Exit");

                ns.Write(sendBytes, 0, sendBytes.Length);

                lbMsg.Items.Add("发送退出命令成功！");

            }

            else

            {

                lbMsg.Items.Add("发送退出命令失败！");

                return;

            }

            ns.Close();

            tcpClient.Close();

            //--------------------------------------------- 

            btnStart.IsEnabled = true;

            btnStop.IsEnabled = false;

        }

 

        void updateUI(object o)

        {

            string str = (string)o;

            lbMsg.Items.Add(str);

        }

    }

}

<Window x:Class="SocketBlockingInterrupt.MainWindow"

      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        Title="MainWindow" Height="350" Width="525">

    <Grid>

        <Button Content="开始侦听" Height="23" HorizontalAlignment="Left" Margin="12,12,0,0" Name="btnStart" VerticalAlignment="Top" Width="75" Click="btnStart_Click" />

        <Button Content="结束侦听" Height="23" HorizontalAlignment="Left" Margin="108,12,0,0" Name="btnStop" VerticalAlignment="Top" Width="75" Click="btnStop_Click" />

        <ListBox Height="258" HorizontalAlignment="Left" Margin="12,41,0,0" Name="lbMsg" VerticalAlignment="Top" Width="479" />

    </Grid>

</Window>