http://odetocode.com/articles/162.aspx
private void Button5_Click(object sender, System.EventArgs e)
{
// first, request the login form to get the viewstate value
HttpWebRequest webRequest = WebRequest.Create(LOGIN_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}&UsernameTextBox={1}&PasswordTextBox={2}&LoginButton=Login",
viewState, USERNAME, PASSWORD
);
// have a cookie container ready to receive the forms auth cookie
CookieContainer cookies = new CookieContainer();
// now post to the login form
webRequest = WebRequest.Create(LOGIN_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
webRequest.GetResponse().Close();
// now we can send out cookie along with a request for the protected page
webRequest = WebRequest.Create(SECRET_PAGE_URL) as HttpWebRequest;
webRequest.CookieContainer = cookies;
responseReader = new StreamReader(webRequest.GetResponse().GetResponseStream());
// and read the response
responseData = responseReader.ReadToEnd();
responseReader.Close();
Response.Write(responseData);
}
