为什么此代码无法检测页面更新？

Question

Well the question pretty much explains it. I'm aware the code is very dirty during String.equals, but I just wanted to see if I understood header responses. Clearly I do not, because I watch in my browser and when a new question is added, my program never outputs "Yep it changed" Why is that?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;
using System.IO;
using System.Net;

namespace ConsoleApplication4
{
    class Program
    {
        static void Main(string[] args)
        {

            Uri myUri = new Uri("http://stackoverflow.com/questions?sort=newest");

            HttpWebRequest myHttpWebRequest = (HttpWebRequest)WebRequest.Create(myUri);



            HttpWebResponse myHttpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse();
            string org = myHttpWebResponse.Headers.GetValues("Date")[0];
            string newone = "";

            while (true) //STRICTING FOR TESTING. THIS WOULD BE A Dos ATTACK AS IT NEVER HAS A DELAY BETWEEN REQUESTS.
            {

                myHttpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse();
                newone = myHttpWebResponse.Headers.GetValues("Date")[0];

                if (!newone.Equals(org))
                    break;
            }


            Console.WriteLine("Yep it changed");
            Console.ReadLine();
        }
    }
}

Answer 1

Your code is checking the same HttpWebResponse , over and over. It's not making new requests, it's only looking at the response from the first (and only request).

From MSDN :

Multiple calls to GetResponse return the same response object; the request is not reissued.

You'll have to put all of the code that makes a request inside the loop, to start the whole request/response process over again.

Also note, that if you were running this code against my website, I would be pretty upset.