C#: Create a WebRequest with HTTP Basic Authentication
http://blog.csdn.net/huangyaoshifog/article/details/4470675
myReq = WebRequest.Create(url);
string username="username";
string password="password";
string usernamePassword = username + ":" + password;
CredentialCache mycache = new CredentialCache();
mycache.Add(new Uri(url), "Basic", new NetworkCredential(username, password));
myReq.Credentials = mycache;
myReq.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(new ASCIIEncoding().GetBytes(usernamePassword)));
WebResponse wr = myReq.GetResponse();
Stream receiveStream = wr.GetResponseStream();
StreamReader reader = new StreamReader(receiveStream, Encoding.UTF8);
string content = reader.ReadToEnd();