在服务器出口断开客户端连接

下面是我使用的服务器代码:

using System;
using Microsoft.AspNet.SignalR;
using Microsoft.AspNet.SignalR.Hubs;
using Microsoft.Owin.Hosting;
using Owin;
using Microsoft.Owin.Cors;
using System.Collections.Generic;

namespace flar3server
{
    class Program
    {
        static void Main(string[] args)
        {
            string url = "http://localhost:8080/";
            using (WebApp.Start(url))
            {
                Console.WriteLine("Server running on {0}", url);
                Console.ReadLine();
            }
        }
        [HubName("flar3hub")]
        public class flare3hub : Hub
        {
            static Dictionary<string, ChatConnection> connections = new Dictionary<string, ChatConnection>();
            Dictionary<string, string> registeredUsers = new Dictionary<string, string>()
            {
                { "test1", "pass1" },
                { "test2", "pass2" },
            };
            /*
            public string Send(string message)
            {
                return message;
            }
             */
            public void Authenticate(string login, string password)
            {
                Console.WriteLine("Login [" + Context.ConnectionId + "] " + login + ":" + password);
                foreach (ChatConnection connection in connections.Values)
                {
                    if (connection.getLogin() == login)
                    {
                        Clients.Caller.Action("ERROR: User already logged in.");
                        return;
                    }
                }
                if (!registeredUsers.ContainsKey(login) || registeredUsers[login] != password)
                {
                    Clients.Caller.Action("ERROR: Login attempt failed.");
                    return;
                }
                connections[Context.ConnectionId] = new ChatConnection(login);
                Clients.Caller.Action("Logged in successfully");
                Clients.All.Action(login + " joined the channel.");
            }
            public void Broadcast(string message)
            {
                try
                {
                    Clients.All.sendMessage(connections[Context.ConnectionId].getLogin(), message);
                }
                catch (KeyNotFoundException)
                {
                    Console.WriteLine("Unpaired [" + Context.ConnectionId + "] " + message);
                }
            }
        }
    }
}

下面是客户端代码:

using System;
using Microsoft.AspNet.SignalR;
using Microsoft.AspNet.SignalR.Hubs;
using Microsoft.AspNet.SignalR.Client;
namespace flar3client_cli
{
    internal class flar3client_cli
    {
        private static void onDisconnected()
        {
            Console.WriteLine("Remote server closed the connection. Press enter to close the application.");
            Console.ReadLine();
            System.Environment.Exit(1);
        }
        private static void Main(string[] args)
        {
            //Set connection
            var connection = new HubConnection("http://localhost:8080/");
            //Make proxy to hub based on hub name on server
            var myHub = connection.CreateHubProxy("flar3hub");
            //Start connection
            connection.Start().ContinueWith(task =>
            {
                if (task.IsFaulted)
                {
                    Console.WriteLine("There was an error opening the connection:{0}",
                                      task.Exception.GetBaseException());
                    Console.WriteLine("Press enter to continue...");
                    Console.ReadLine();
                    connection.Stop();
                    System.Environment.Exit(1);
                }
                else
                {
                    Console.WriteLine("Connected");
                }
            }).Wait();
            connection.Closed += onDisconnected;

            myHub.On<string>("Action", param =>
            {
                Console.WriteLine(param);
            });
            myHub.On<string>("SendMessage", param =>
            {
                Console.WriteLine(param);
            });
            myHub.Invoke<string>("Authenticate", "test1", "pass1").Wait();

            while (true)
            {
                myHub.Invoke<string>("Broadcast", Console.ReadLine()).Wait();
            }

我如何使服务器断开所有客户端当它的应用程序窗口关闭，以便客户端可以发现?