C＃异步TCP侦听器不取消循环

我正在使用TCPListener类异步编写C＃中的服务器 . 我目前有以下代码作为我的网络监听器类：

public class NetworkListener
{
    private readonly SessionController _sessions;
    private readonly TcpListener _server;

    public NetworkListener(KernelConfiguration configuration, SessionController sessions)
    {
        _server = new TcpListener(new IPEndPoint(IPAddress.Any, configuration.Network.port));
        _server.Start();

        _sessions = sessions;
    }

    public async Task StartAccepting(CancellationToken token)
    {
        while (!token.IsCancellationRequested)
        {
            var client = await _server.AcceptTcpClientAsync();
            Console.WriteLine($"New connection from {client.Client.RemoteEndPoint}.");
            _sessions.AddSession(client, Guid.NewGuid(), out var session);
            await session.StartReceiving();
        }

        Console.WriteLine("stop");
    }

    public void Dispose()
    {
        _server.Stop();
    }
}

作为我的program.cs我有：

internal class Program
{
    private static NetworkListener _networkListener;
    private static CancellationTokenSource _cancellationTokenSource;

    private static async Task Main(string[] args)
    {
        _networkListener = new NetworkListener(new KernelConfiguration(), new SessionController());
        _cancellationTokenSource = new CancellationTokenSource();

        var thread = new Thread(ProgressConsoleCommands);
        thread.Start();

        try
        {
            await _networkListener.StartAccepting(_cancellationTokenSource.Token);
        }
        finally
        {
            _networkListener.Dispose();
        }
    }

    private static void ProgressConsoleCommands()
    {
        while (true)
        {
            var command = Console.ReadLine();
            Console.WriteLine(command);

            switch (command)
            {
                case "close":
                    Console.WriteLine("called");
                    _cancellationTokenSource.Cancel();
                    break;
            }
        }
    }
}

What currently happens:

我启动了我的程序 . 它启动TcpListener . 我可以连接到TcpListener正在侦听的端口 . 当我输入“close”（当然没有引号）时，它会写入“called” . 但是，“stop”不会写入控制台，TcpListener仍然接受新问题 .

Desired state:

每当我输入“关闭”时，它应该停止接受新连接，写入“停止”并退出循环 . 然后它应该调用我的NetworkListener类的Dispose函数来完全停止TcpListener并处理它 .