如何使用httpwebrequest和proxy访问URL

Question

基本上，我想在C＃中使用HTTPWebRequest来访问网页。但是我的程序崩溃了，什么也没发生。

WebProxy myProxy = new WebProxy(prx);
        CookieContainer cookieJar = new CookieContainer();
        HttpWebRequest request = HttpWebRequest.Create(url) as HttpWebRequest;

       request.Method = "GET";
       request.Proxy = myProxy;
       request.Referer = "http://anyrefererItypehere";
       request.CookieContainer = cookieJar;
       request.ContentType = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
       request.KeepAlive = true;
       request.Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip, deflate");
       request.UserAgent = "Mozilla/5.0 (Windows NT 5.1; rv:10.0.2) Gecko/20100101 Firefox/10.0.2";
       request.Headers.Add(HttpRequestHeader.AcceptLanguage, "Accept-Language: en-us,en;q=0.5");
       request.Host = "anyblogItypehere.tumblr.com";

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

        Stream stream = webResponse.GetResponseStream();
        StreamReader reader = new StreamReader(stream, Encoding.UTF8);
        String responseString = reader.ReadToEnd();

        webResponse.Close();
        rtbSource.Text = responseString;