webservice引用

 class VidyoPortalUserServiceWithAuthentication : VidyoPortalUserService
    {
        String _username;
        String _password;
        public VidyoPortalUserServiceWithAuthentication(String username, String password)
        {
            _username = username;
            _password = password;
        }
        protected override WebRequest GetWebRequest(Uri uri)
        {
            WebRequest wr = base.GetWebRequest(uri);
            wr.Headers.Add("Authorization", "Basic " +
                Convert.ToBase64String(Encoding.ASCII.GetBytes(_username + ":" + _password)));
            return wr;
        }
    }

VidyoPortalUserServiceWithAuthentication vpus = new VidyoPortalUserServiceWithAuthentication(this.tbxID.Text, this.tbxPwd.Text);


                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(RequestString);

                request.AllowAutoRedirect = false;
                request.Method = "GET";
                // Get Found (302) response.
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();