HttpWebRequest代理访问网站

private void button1_Click(object sender, EventArgs e)

        {

            string str ="http://www.7y8.com/V/ip.asp";

            MessageBox.Show("访问的IP地址是："+getIPAddr(GetResponseStr(str)));

        }



        //使用代理访问

        private string GetResponseStr(string str)

        {

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

            request.Proxy = CreatProxy("http://65.110.17.142:80","","");

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();

            Stream stream = response.GetResponseStream();//获得回应的数据流

            //将数据流转成 String 

            string result = new StreamReader(stream, System.Text.Encoding.UTF8).ReadToEnd();

            return result;

        }



        

        /// <summary>

        /// 创建代理对象

        /// </summary>

        /// <param name="str_IP">HTTP代理地址(默认是80端口)</param>

        /// <param name="str_UserName">用户名(匿名则用户名和密码为空)</param>

        /// <param name="str_Pwd">密码</param>

        /// <returns></returns>

        private WebProxy CreatProxy(string str_IP, string str_UserName, string str_Pwd)

        {

            str_IP = str_IP.ToUpper().IndexOf("HTTP://") > -1 ? str_IP : "http://" + str_IP;

            WebProxy myProxy = new WebProxy();

            myProxy.Address = new Uri(str_IP);

            myProxy.Credentials = new NetworkCredential(str_UserName, str_Pwd);

            return myProxy;

        }







        //抓取页面上显示的IP地址

        private string getIPAddr(string str)

        {

            System.Text.RegularExpressions.Regex reg = new System.Text.RegularExpressions.Regex(@"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}");

            return reg.Match(str).Value.ToString();

        }