programmatically login to a wep page

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  11 years ago

  by Lufuno

  Mbulungeni

  Johanessburg, South Africa

  Joined 12 years ago
  Hello! I have a url to a web page which requires a the login credentials which i do have.... so i want to programmatically login to that web page by passing username and password.. The code below doesn't seem to work because it doesn't pass the login page.. so anyone PLEASE HELP.. WebClient webClient = new WebClient(); // first, request the login form to get the viewstate value HttpWebRequest webRequest = WebRequest.Create("url") as HttpWebRequest; StreamReader responseReader = new StreamReader( webRequest.GetResponse().GetResponseStream() ); string responseData = responseReader.ReadToEnd(); responseReader.Close(); // extract the viewstate value and build out POST data string viewState = ExtractViewState(responseData); string postData = String.Format( "__VIEWSTATE={0}&txtUserName={1}&txtPassword={2}&btnLogin=Login", viewState, "name", "Password" ); // webClient.UploadData("url", "POST", Encoding.ASCII.GetBytes(postData)); // have a cookie container ready to receive the forms auth cookie CookieContainer cookies = new CookieContainer(); // now post to the login form webRequest = WebRequest.Create("url") as HttpWebRequest; webRequest.Method = "POST"; webRequest.ContentType = "application/x-www-form-urlencoded"; webRequest.CookieContainer = cookies; // write the form values into the request message StreamWriter requestWriter = new StreamWriter(webRequest.GetRequestStream()); requestWriter.Write(postData); requestWriter.Close(); //// we don't need the contents of the response, just the cookie it issues //WebResponse wb = webRequest.GetResponse(); //string gg = wb.ToString(); //wb.Close(); // now we can send out cookie along with a request for the protected page webRequest = WebRequest.Create("url") as HttpWebRequest; webRequest.CookieContainer = cookies; responseReader = new StreamReader(webRequest.GetResponse().GetResponseStream()); // and read the response responseData = responseReader.ReadToEnd(); responseReader.Close(); } private string ExtractViewState(string s) { string viewStateNameDelimiter = "__VIEWSTATE"; string valueDelimiter = "value=\""; int viewStateNamePosition = s.IndexOf(viewStateNameDelimiter); int viewStateValuePosition = s.IndexOf( valueDelimiter, viewStateNamePosition ); int viewStateStartPosition = viewStateValuePosition + valueDelimiter.Length; int viewStateEndPosition = s.IndexOf("\"", viewStateStartPosition); return HttpUtility.UrlEncodeUnicode( s.Substring( viewStateStartPosition, viewStateEndPosition - viewStateStartPosition ) ); }
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