求助：定时循环使用HttpWebRequest访问网页数据，报错未处理的“System.StackOverflowException”类型的异常

qingxin113 2014-06-05 08:13:53

类似网页辅助工具的代码，使用两三个线程定时通过HttpWebRequest访问不同的网页数据获取信息。
运行大概三、四个小时后，报错未处理的“System.StackOverflowException”类型的异常出现在 mscorlib.dll 中。
每次调用也作了垃圾回收，不明白应怎么解决。谢谢
下面是出错的代码：

/// <summary>

        /// Web的Get方式

        /// </summary>

        /// <param name="Url">网址URL</param>

        /// <param name="cc">CookieContainer</param>

        /// <returns></returns>

        public static string GetHtmlMethodForCommon(string Url, ref CookieContainer cc)

        {

            string strHtmlReturn = "";

            HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(Url);

            //属性配置  

            webRequest.AllowWriteStreamBuffering = true;

            webRequest.Credentials = System.Net.CredentialCache.DefaultCredentials;

            webRequest.MaximumResponseHeadersLength = -1;

            webRequest.Accept = "image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-silverlight, application/x-ms-application, application/x-ms-xbap, application/vnd.ms-xpsdocument, application/xaml+xml, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, application/QVOD, application/QVOD, */*";

            webRequest.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; (R1 1.5); .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022; InfoPath.2; .NET4.0C; .NET4.0E; Alexa Toolbar; u9dnfsh)";

            webRequest.ContentType = "application/x-www-form-urlencoded";

            webRequest.Method = "GET";



            //如果服务器返回错误，他还会继续再去请求，不会使用之前的错误数据，做返回数据

            webRequest.ServicePoint.Expect100Continue = false;

            webRequest.Timeout = 200000;

            ServicePointManager.DefaultConnectionLimit = 50;



            webRequest.Headers.Add("Accept-Language", "zh-cn");

            webRequest.Headers.Add("Accept-Encoding", "gzip,deflate");

            webRequest.KeepAlive = true;

            webRequest.CookieContainer = cc;

            try

            {



                //获取服务器返回的资源

              //运行三四个小时后，此处报错

                using (HttpWebResponse webResponse = (HttpWebResponse)webRequest.GetResponse())

                {

                    if (webResponse.StatusCode == HttpStatusCode.RequestTimeout)//此处作超时响应判断

                    {

                        System.Threading.Thread.Sleep(1000);

                        return null;

                    }

                    else

                    {

                        Stream responseStream = webResponse.GetResponseStream();

                        using (StreamReader reader = new StreamReader(webResponse.GetResponseStream(), Encoding.GetEncoding("utf-8")))

                        {

                            cc.Add(webResponse.Cookies);

                            strHtmlReturn = reader.ReadToEnd();

                        }

                    }

                }

            }

            catch (WebException ex)

            {

                strHtmlReturn = "";

                throw ex;

            }

            catch (Exception ex)

            {

                strHtmlReturn = "";

                throw ex;

            }

            finally

            {

                webRequest.Abort();

            }

            return strHtmlReturn;

        }