Ein Weg, um herauszufinden, Umleitungs-URL

WebRequest folgt umleitet, ohne dass der Benutzer eingreifen, so wenn die Umleitungen sind mit 301/302-status-codes die folgenden arbeiten

WebRequest request = WebRequest.Create(destination);
WebResponse response = request.GetResponse();
Console.WriteLine(response.ResponseUri);

Wenn die Weiterleitungen erstellt werden, mithilfe von javascript oder HTTP-Equiv-meta-tags dann tun zu müssen, analysieren Sie die Seite und suchen Sie nach diesen. Die HTML-agility-pack ist wahrscheinlich der beste Weg, dies zu tun.

Nehmen, diese ein wenig weiter das folgende ist eine Klasse, die manuell aufgelöst werden die wichtigsten HTTP-redirect-status-codes, den Aufbau einer Geschichte, wie es geht

///<summary>
///Digs through HTTP redirects until a non-redirected URL is found.
///</summary>
public class Digger
{
    ///<summary>
    ///Initializes a new instance of the <see cref="Digger"/> class.
    ///</summary>
    public Digger() : this(20)
    {            
    }

    ///<summary>
    ///Initializes a new instance of the <see cref="Digger"/> class.
    ///</summary>
    ///<param name="maximumDepth">The maximum depth of redirects to parse.</param>
    public Digger(int maximumDepth)
    {
        this.MaximumDepth = maximumDepth;
    }

    ///<summary>
    ///Gets the maximum depth of redirects to parse.
    ///</summary>
    ///<value>The maximum depth of redirects to parse.</value>
    public int MaximumDepth
    {
        get; 
        private set;
    }

    ///<summary>
    ///Resolves any redirects at the specified URI.
    ///</summary>
    ///<param name="destination">The initial URI.</param>
    ///<returns>The URI after resolving any HTTP redirects.</returns>
    public Uri Resolve(Uri destination)
    {
        List<Uri> redirectHistory = new List<Uri>();
        return this.Resolve(destination, redirectHistory);
    }

    ///<summary>
    ///Resolves any redirects at the specified URI.
    ///</summary>
    ///<param name="destination">The initial URI.</param>
    ///<param name="redirectHistory">A collection of <see cref="Uri"/> objects representing the redirect history.</param>
    ///<returns>The URI after resolving any HTTP redirects.</returns>
    public Uri Resolve(Uri destination, ICollection<Uri> redirectHistory)
    {
        redirectHistory.Add(destination);
        return this.Resolve(destination, this.MaximumDepth, redirectHistory);
    }

    ///<summary>
    ///Resolves any redirects at the specified URI.
    ///</summary>
    ///<param name="destination">The initial URI.</param>
    ///<param name="hopsLeft">The maximum number of redirects left to follow.</param>
    ///<param name="redirectHistory">A collection of <see cref="Uri"/> objects representing the redirect history.</param>
    ///<returns>The URI after resolving any HTTP redirects.</returns>
    private Uri Resolve(Uri destination, int hopsLeft, ICollection<Uri> redirectHistory)
    {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(destination);
        request.AllowAutoRedirect = false;
        request.Method = "HEAD";

        HttpWebResponse response = (HttpWebResponse)request.GetResponse();

        Uri resolvedUri;

        if (response.StatusCode == HttpStatusCode.Redirect || 
            response.StatusCode == HttpStatusCode.Moved || 
            response.StatusCode == HttpStatusCode.MovedPermanently)
        {
            if (hopsLeft > 0)
            {
                Uri redirectUri = new Uri(response.GetResponseHeader("Location"));
                if (redirectHistory.Contains(redirectUri))
                {
                    throw new Exception("Recursive redirection found");
                }

                redirectHistory.Add(redirectUri);
                resolvedUri = this.Resolve(redirectUri, hopsLeft - 1, redirectHistory);
            }
            else
            {
                throw new Exception("Maximum redirect depth reached");
            }
        }
        else
        {
            resolvedUri = response.ResponseUri;
        }

        return resolvedUri;            
    }
}