C#实现http服务

using System.Net;

class HttpTask
{
    public delegate String RunCmdCallback(string cmd);
    private Dictionary<string, RunCmdCallback> routers=new Dictionary<string, RunCmdCallback>();
    public void addRouter(String router,RunCmdCallback cb = null)
    {
        if (!router.EndsWith('/'))
        {
            this.routers.Add(router + '/', cb);
        }
        else
        {
            this.routers.Add(router, cb);
        }
    }
    void  runHttpServer(UInt32 port ,String ip="")
    {
        if (!System.Net.HttpListener.IsSupported)
        {
            Console.WriteLine("Windows XP SP2 or Server 2003 is required to use the HttpListener class.");
            return;
        }
        if (ip==String.Empty)
        {
            ip = "127.0.0.1";
        }
        // Create a listener.
        HttpListener listener = new HttpListener();
        foreach (KeyValuePair<string,RunCmdCallback> kp in this.routers)
        {
            listener.Prefixes.Add($"http://{ip}:{port}{kp.Key}");
        }
        listener.Start();
        Console.WriteLine($"Http Server Listening At http://{ip}:{port}...");
        while (true)
        {
           S: HttpListenerContext context = listener.GetContext();
            HttpListenerRequest request = context.Request;
            // Obtain a response object.
            HttpListenerResponse response = context.Response;
            // Construct a response.
            foreach (KeyValuePair<string, RunCmdCallback> kp in this.routers)
            {
                if (request.RawUrl.IndexOf(kp.Key) == 0)
                {
                    String prms = request.RawUrl.Substring(kp.Key.Length);
                    string ret= kp.Value.Invoke(prms);
                    byte[] buf = System.Text.Encoding.UTF8.GetBytes(ret);
                    response.ContentLength64 = buf.Length;
                    System.IO.Stream ot = response.OutputStream;
                    ot.Write(buf, 0, buf.Length);
                    ot.Close();
                    goto S;
                }

            }
            string responseString = "error";
            byte[] buffer = System.Text.Encoding.UTF8.GetBytes(responseString);
            response.ContentLength64 = buffer.Length;
            System.IO.Stream output = response.OutputStream;
            output.Write(buffer, 0, buffer.Length);
            output.Close();
        }
        listener.Stop();
    }

    static void Main()
    {
        HttpTask ht = new HttpTask();
        //定义打印命令 
        ht.addRouter("/print/", new RunCmdCallback((string cmd) => {
            //参数
            //http://127.0.0.1:8080/print/{打印机ID或者其他参数}
            Console.WriteLine(cmd);
            return cmd;
        }));
        //关闭打印机 路由 
        ht.addRouter("/close/", new RunCmdCallback((string cmd) => {

            //参数
            //http://127.0.0.1:8080/close/{打印机ID或者其他参数}
            Console.WriteLine(cmd);
            return cmd;
        }));
        ht.runHttpServer(8080, "127.0.0.1");
    }
}