(Jun 18, 2018 11:13 PM)Snowfox Wrote:  Yes. I've used it once. Get the cookies from WebBrowser control like below (If you are using winforms)

Code

public CookieContainer GetCookieContainer()
   {
       CookieContainer container = new CookieContainer();

       foreach (string cookie in webBrowser1.Document.Cookie.Split(';'))
       {
           string name = cookie.Split('=')[0];
           string value = cookie.Substring(name.Length + 1);
           string path = "/";
           string domain = ".google.com"; //change to your domain name
           container.Add(new Cookie(name.Trim(), value.Trim(), path, domain));
       }

       return container;
   }

Next, serialize the cookiecontainer and save something like cookies.dat to reuse(deserialize) in HttpWebrequest

If you are trying to pass the cookies form native IE browser then

Code

[DllImport("wininet.dll", SetLastError = true)]
   public static extern bool InternetGetCookieEx(
       string url,
       string cookieName,
       StringBuilder cookieData,
       ref int size,
       Int32  dwFlags,
       IntPtr  lpReserved);

   private const Int32 InternetCookieHttponly = 0x2000;

/// <summary>
/// Gets the URI cookie container.
/// </summary>
/// <param name="uri">The URI.</param>
/// <returns></returns>
public static CookieContainer GetUriCookieContainer(Uri uri)
{
   CookieContainer cookies = null;
   // Determine the size of the cookie
   int datasize = 8192 * 16;
   StringBuilder cookieData = new StringBuilder(datasize);
   if (!InternetGetCookieEx(uri.ToString(), null, cookieData, ref datasize, InternetCookieHttponly, IntPtr.Zero))
   {
       if (datasize < 0)
           return null;
       // Allocate stringbuilder large enough to hold the cookie
       cookieData = new StringBuilder(datasize);
       if (!InternetGetCookieEx(
           uri.ToString(),
           null, cookieData,
           ref datasize,
           InternetCookieHttponly,
           IntPtr.Zero))
           return null;
   }
   if (cookieData.Length > 0)
   {
       cookies = new CookieContainer();
       cookies.SetCookies(uri, cookieData.ToString().Replace(';', ','));
   }
   return cookies;
}

Source : Stackoverflow

And I believe you don't need to pass the cookies from browser to HttpWebRequest. You can do the same requests from HttpWebrequest to avoid above steps.

Hope this helps.