C# 404 error ( Webclient)

Question

So i have this code which i'm trying to find if Twitter / ? is in the source of the twitter.com/name ( to verify if the user exist) When the user exist, it works fine, when the user doesn't, it gives a 404 error and stop. is there anyway to ignore the 404 error and make it still look at the source code of that page? because if we go to ex: view-source:https://twitter.com/pogosode , it doesn't exist but we can still see the source..

foreach (Membre noms in p_nom)
        {
            string websiteName = "https://twitter.com/" + noms.NomMembre;
            string source = (new WebClient()).DownloadString(websiteName);
            if (source.Contains("<title>Twitter / ?</title>"))
                {
                p_disponible.Add(new MembreVerifier(noms.NomMembre));
                }
        }

Twitter has an API designed for this: https://dev.twitter.com/docs/api/1.1/get/users/search — Arran, Jan 02 '14 at 19:57
Why not just detect the 404 error and drive the logic from that? — Jeff Siver, Jan 02 '14 at 20:00

Oskar Sjöberg · Answer 1 · 2014-01-02T20:32:35.493

0

You can catch the WebException exception and read the response from the Response property.

Example:

foreach (Membre noms in p_nom)
{
    string source = "";
    try
    {           
        string websiteName = "https://twitter.com/" + noms.NomMembre;
        source = (new WebClient()).DownloadString(websiteName);     
    }
    catch (WebException ex)
    {
        using (var stream = ex.Response.GetResponseStream())
        {
            // Copy stream to buffer.
            var buffer = new byte[stream.Length];
            stream.Read(buffer, 0, (int)stream.Length);

            // Decode byte array to UTF-8 string.
            source = Encoding.UTF8.GetString(buffer);
        }
    }

    if (source.Contains("<title>Twitter / ?</title>"))
    {
         p_disponible.Add(new MembreVerifier(noms.NomMembre));
    }
}

edited Jan 02 '14 at 20:32

answered Jan 02 '14 at 20:07

Oskar Sjöberg

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Thanks! It works, the only thing is that i've made and else{*do something*} for when the source doesn't contain the twitter / ? but it doesn't do the things in the else – user2737579 Jan 02 '14 at 20:18
It is beacuse when an exception occurs (as it will when you get a 404) execution of the code will stop and the program jumps to the catch part. So you will have to modify your logic to account for that. – Oskar Sjöberg Jan 02 '14 at 20:21
Yea, i've added that : // TODO: Use content. if (content.Contains("Twitter / ?")) { //p_disponible.Add(new MembreVerifier(noms.NomMembre)); Console.WriteLine("{0} is available for twitter.", noms.NomMembre); } else { Console.WriteLine("Too bad! {0} isn't available for twitter.", noms.NomMembre); } into the catch and the else doesn't work :O – user2737579 Jan 02 '14 at 20:24
I've changed the code to better fit your purpose. – Oskar Sjöberg Jan 02 '14 at 20:32

C# 404 error ( Webclient)

1 Answers1