Question

Is it possible to Post some data from window based app to a web-server ? Lets be practical

ASCIIEncoding encodedText = new ASCIIEncoding();
string postData = string.Format("txtUserID={0}&txtPassword={1}", txtUName.Text, txtPassword.Text);
byte[] data = encodedText.GetBytes(postData);
HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create("http://www.aimlifes.com/office/Login.aspx");
webRequest.Method = "POST";
webRequest.ContentType = "text/html";
webRequest.ContentLength = data.Length;
Stream strm = webRequest.GetRequestStream();
strm.Write(data, 0, data.Length);

txtUrlData.Text = GetPageHtml("http://www.aimlifes.com/office/ReceiveRecharge.aspx");

strm.Close();

GetPageHtml Function:

public string  GetPageHtml(String Url)
{
  WebClient wbc = new WebClient();
  return new System.Text.UTF8Encoding().GetString(wbc.DownloadData(Url));
}

What i’m trying is Login To xyz.com site using given credential and fetch the html data in a TextArea. GetPageHtml() function fetch’s the html data. But the main problem is Posting the login details is not working, i mean m not able to get login to the xyz.com

Answer 1

If the site uses cookies to tack authenticated users you might try this:

public class CookieAwareWebClient : WebClient
{
    public CookieAwareWebClient ()
    {
        CookieContainer = new CookieContainer();
    }

    public CookieContainer CookieContainer { get; set; }

    protected override WebRequest GetWebRequest(Uri address)
    {
        var request = base.GetWebRequest(address);
        ((HttpWebRequest)request).CookieContainer = CookieContainer;
        return request;
    }
}

public class Program
{
    static void Main()
    {
        using (var client = new CookieAwareWebClient())
        {
            var values = new NameValueCollection
            {
                { "txtUserID", "foo" },
                { "txtPassword", "secret" }
            };
            // Authenticate. As we are using a cookie container
            // the user will be authenticated on the next requests
            // using this client
            client.UploadValues("http://www.aimlifes.com/office/Login.aspx", values);

            // The user is now authenticated:
            var result = client.DownloadString("http://www.aimlifes.com/office/ReceiveRecharge.aspx");
            Console.WriteLine(result);
        }
    }
}