Using WebClient or WebRequest to login to a website and access data

Question

I'm trying to access restricted data on a website using WebClient/WebRequest. There is no official API in that website, so what I'm trying to do is simply fill the HTML form and post the values to the server, so I'm logged in.

I tried this and this, but it doesn't look like the upcoming requests are logged in.

The latter example is much more appealing since I obviously prefer WebClient, but legacy WebRequest will do.

Anyway, in the first example I think it did login, but the upcoming requests that access the private data return a page with a message "This is member only content".

How to make a WebClient permanently logged in?

Answer 1

Update:

See my comment below.

---

Here's what I did and it works (credit).

Add this class first:

namespace System.Net
{
  using System.Collections.Specialized;
  using System.Linq;
  using System.Text;

  public class CookieAwareWebClient : WebClient
  {
    public void Login(string loginPageAddress, NameValueCollection loginData)
    {
      CookieContainer container;

      var request = (HttpWebRequest)WebRequest.Create(loginPageAddress);

      request.Method = "POST";
      request.ContentType = "application/x-www-form-urlencoded";

      var query = string.Join("&", 
        loginData.Cast<string>().Select(key => $"{key}={loginData[key]}"));

      var buffer = Encoding.ASCII.GetBytes(query);
      request.ContentLength = buffer.Length;
      var requestStream = request.GetRequestStream();
      requestStream.Write(buffer, 0, buffer.Length);
      requestStream.Close();

      container = request.CookieContainer = new CookieContainer();

      var response = request.GetResponse();
      response.Close();
      CookieContainer = container;
    }

    public CookieAwareWebClient(CookieContainer container)
    {
      CookieContainer = container;
    }

    public CookieAwareWebClient()
      : this(new CookieContainer())
    { }

    public CookieContainer CookieContainer { get; private set; }

    protected override WebRequest GetWebRequest(Uri address)
    {
      var request = (HttpWebRequest)base.GetWebRequest(address);
      request.CookieContainer = CookieContainer;
      return request;
    }
  }
}

Usage:

public static void Main()
{
  var loginAddress = "www.mywebsite.com/login";
  var loginData = new NameValueCollection
    {
      { "username", "shimmy" },
      { "password", "mypassword" }
    };

  var client = new CookieAwareWebClient();
  client.Login(loginAddress, loginData);
}