using HttpWebRequest to login to a website

Question

What's the best (& easiest) way of using HttpWebRequest to access certain website (login). 

Thanks!

Answer 1

The best way to access a login site is using WebBrowser control.

Otherwise if you dont have any other option then using HttpWebRequest. I recomend you to watch http requests and responses with a tool like ieHttpHeaders(http://www.blunck.se/iehttpheaders/iehttpheaders.html) Then you can make your requests. But you'll have to manage cookies that sent with header. Viewstate information vs vs. I mean when te response comes you will have to store viewstate information and send it back at your request.

Here are some threads and some documentation about WebBrowser Control:

http://msdn.microsoft.com/en-us/library/2te2y1x6.aspx
http://msdn.microsoft.com/en-us/library/ms171711.aspx
http://social.msdn.microsoft.com/Forums/en-US/winforms/thread/f13f0b41-98c9-456d-8caf-1f274bd3d7bb
http://social.msdn.microsoft.com/Forums/en-US/winforms/thread/acf8ec6a-0f64-48ce-8e17-53c005123562
http://social.msdn.microsoft.com/Forums/en-US/winforms/thread/acf8ec6a-0f64-48ce-8e17-53c005123562

and a sample code for httprequest.

    public class Client : WebClient
    {
        public void setDefaultHeaders()
        {

            this.Proxy = WebProxy.GetDefaultProxy();
            this.Proxy.Credentials = CredentialCache.DefaultCredentials;

            this.Headers.Clear();
            this.Headers.Add("Accept", @"image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, application/x-shockwave-flash, */*");
            this.Headers.Add("Accept-Language", "tr");
            this.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
           this.Headers.Add("UA-CPU", "x86");
            this.Headers.Add("Cache-Control", "no-cache");
           this.Headers.Add("User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)");


        }
    }

    public class Request
    {
        string _postData;
        string _postUrl;
        byte[] _postByteArray;
        byte[] _responseArray;
        string _response;
        string _jSessionId;

        public string JSessionId
        {
            get { return _jSessionId; }
            set { _jSessionId = value; }
        }

        public byte[] PostByteArray
        {
            get
            {
                return _postByteArray;
            }
            set
            {
                _postByteArray = value;
            }
        }
        public byte[] ResponseArray
        {
            get
            {
                return _responseArray;
            }
            set
            {
                _responseArray = value;
            }
        }
        public string Response
        {
            get
            {
                return _response;
            }
            set
            {
                _response = value;
            }
        }
        public string PostData
        {
            get
            {
                return _postData;
            }
            set
            {
                _postData = value;
            }
        }
        public string PostUrl
        {
            get
            {
                return _postUrl;
            }
            set
            {
                _postUrl = value;
            }
        }
        public void getResponse()
        {


        }
    }
    public class Helper
    {
        public void getResponse(Request parRequest, Client parClient)
        {
            try
            {
                Encoding iso = Encoding.GetEncoding("iso-8859-9");
                if (parRequest.PostData == "")
                {
                    HttpWebRequest req = (HttpWebRequest)(WebRequest.Create(parRequest.PostUrl));
                    req.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0b; Windows NT 5.1)";
                    req.Method = "GET";
                    req.KeepAlive = false;
                    req.Timeout = 1000000;
                    req.Proxy = WebProxy.GetDefaultProxy();
                    req.Proxy.Credentials = CredentialCache.DefaultCredentials;
                    HttpWebResponse res = ((HttpWebResponse)req.GetResponse());
                    StreamReader sr = new StreamReader(res.GetResponseStream(),iso);
                    parRequest.Response = sr.ReadToEnd();
                }
                else
                {
                    
                    parRequest.PostByteArray = Encoding.UTF8.GetBytes(parRequest.PostData);
                    parRequest.ResponseArray = parClient.UploadData(parRequest.PostUrl, "POST", parRequest.PostByteArray);
                    parRequest.Response = iso.GetString(parRequest.ResponseArray);
                }
            }
            catch (Exception Ex)
            {
                          }
        }
        public void getResponse(Request parRequest, Client parClient,bool usePost)
        {
            try
            {
                Encoding iso = Encoding.GetEncoding("iso-8859-9");
               

                    parRequest.PostByteArray = Encoding.UTF8.GetBytes(parRequest.PostData);
                    parRequest.ResponseArray = parClient.UploadData(parRequest.PostUrl, "POST", parRequest.PostByteArray);
                    parRequest.Response = iso.GetString(parRequest.ResponseArray);
                
            }
            catch (Exception Ex)
            {
                
            }
        }
}
    public class Sample
    {
        Request insRequest = new Request();
        Helper insHelper = new Helper();
        Client insClient = new Client();
        private void CallResponse()
        {
            insHelper.getResponse(insRequest, insClient);
        }
        private void CallResponse(bool usePost)
        {
            insHelper.getResponse(insRequest, insClient,true);
        }


        int queryCount = 0;
        string sessionId = "";
        string userName = "";
        string password = "";
        public void Login()
        {


                    insClient.setDefaultHeaders();
                    insRequest.PostData = "";
                    insRequest.PostUrl = "http://address";
                    CallResponse(true);
                    sessionId = insClient.ResponseHeaders["Set-Cookie"];


                    insClient.setDefaultHeaders();
                    insClient.Headers.Add("Cookie", sessionId);
                    insRequest.PostData = "userCode=" + userName + "&userPass=" + password + "&sendButton.x=0&sendButton.y=0";
                    insRequest.PostUrl = "http://address";
                    CallResponse();
}
}

Answer 2

Thanks Tamer, I still haven't used your code for login to an external website but I am working on something similar at the moment. Right now all I want to do is call for URL that will process something (no need for login). I have to use HttpWebRequest. Basically this URL will produce an image which I have to grab and store it inside certain folder on my hard drive. Any guidelines?

Thanks a lot! :))

Answer 3

Hi,

Hope this is what you are looking for.

            Encoding iso = Encoding.GetEncoding("iso-8859-9");
            HttpWebRequest req = (HttpWebRequest)(WebRequest.Create("http://i2.social.microsoft.com/Image.avatr?size=Large&user=Tamer%20Oz&id=b86704f4-ef5c-4a1b-bcb3-dc1509ed45a1"));
            req.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0b; Windows NT 5.1)";
            req.Method = "GET";
            req.KeepAlive = false;
            req.Timeout = 1000000;
            req.Proxy = WebProxy.GetDefaultProxy();
            req.Proxy.Credentials = CredentialCache.DefaultCredentials;
            HttpWebResponse res = ((HttpWebResponse)req.GetResponse());
            StreamReader read = new StreamReader(res.GetResponseStream(), iso);
            StreamWriter write = new StreamWriter(@"C:\users\tamer\desktop\b.jpg", false, iso);
            write.Write(read.ReadToEnd());
            read.Close();
            write.Close();

Answer 4

it works like a charm! :)) One question, why do you use Encoding iso = Encoding.GetEncoding("iso-8859-9");?

Answer 5

It's encoding for Turkish normally I use this code to get the source of a page.

You can use Encoding.Default