求数据包抓取、解析、修改、恢复、转发方法

#region 获取字符流
        /// <summary>
        /// 获取字符流
        /// </summary>
        //---------------------------------------------------------------------------------------------------------------
        // 示例:
        // System.Net.CookieContainer cookie = new System.Net.CookieContainer(); 
        // Stream s = HttpHelper.GetStream("http://ptlogin2.qq.com/getimage?aid=15000102&0.43878429697395826", cookie);
        // picVerify.Image = Image.FromStream(s);
        //---------------------------------------------------------------------------------------------------------------
        /// <param name="url">地址</param>
        /// <param name="cookieContainer">cookieContainer</param>
        public static Stream GetStream(string url, CookieContainer cookieContainer)
        {
            currentTry++;

            HttpWebRequest httpWebRequest = null;
            HttpWebResponse httpWebResponse = null;

            try
            {
                httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(url);
                httpWebRequest.CookieContainer = cookieContainer;
                httpWebRequest.ContentType = contentType;
                httpWebRequest.ServicePoint.ConnectionLimit = maxTry;
                httpWebRequest.Referer = url;
                httpWebRequest.Accept = accept;
                httpWebRequest.UserAgent = userAgent;
                httpWebRequest.Method = "GET";

                httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
                Stream responseStream = httpWebResponse.GetResponseStream();
                currentTry--;
                return responseStream;
            }
            catch (Exception e)
            {
                if (currentTry <= maxTry)
                {
                    GetHtml(url, cookieContainer);
                }

                currentTry--;

                if (httpWebRequest != null)
                {
                    httpWebRequest.Abort();
                } if (httpWebResponse != null)
                {
                    httpWebResponse.Close();
                }
                return null;
            }
        }
        #endregion