用户认证

HttpWebRequest可以实现的啊

最简单的方法，就是把用户名和密码放入url中

比如：http://username:password@www.abc.com/

复杂的办法可以在请求的header里面添加Authorization。格式为：Basic + base64（username:password）

如：

public static string SendDataByGET(string Url, string postDataStr, ref CookieContainer cookie)
        {
            try
            {
                string url = Url + (postDataStr == "" ? "" : "?") + postDataStr;
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
                //if (cookie.Count == 0)
                //{
                //    request.CookieContainer = new CookieContainer();
                //    cookie = request.CookieContainer;
                //}
                //else
                //{
                request.CookieContainer = cookie;
                //}
                request.KeepAlive = true;
                request.Headers.Add("Authorization", "Basic Ym9uc29uOmJvbnNvbg==");
                request.CookieContainer = cookie;
                request.Credentials = CredentialCache.DefaultCredentials;

request.Method = "GET";
                //request.Timeout = 1000 * 300;
                request.ContentType = "text/html;charset=gb2312";
                request.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; MyIE2 0.3; Mogi/1; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)";

HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                Stream myResponseStream = response.GetResponseStream();
                StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("gb2312"));
                string retString = myStreamReader.ReadToEnd();
                myStreamReader.Close();
                myResponseStream.Close();

return retString;
            }
            catch (Exception ex)
            {
                return "提交出错:" + ex.Message;
            }
        }