写了一个Windows服务，通过C#模拟网站用户登录并爬取BUG列表查询有没有新的BUG，并提醒我

1、HttpUtil工具类，用于模拟用户登录以及爬取网页：

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading;

namespace Utils
{
    /// <summary>
    /// Http上传下载文件
    /// </summary>
    public class HttpUtil
    {
        #region cookie设置
        private static CookieContainer m_Cookie = new CookieContainer();

        public static void SetHttpCookie(CookieContainer cookie)
        {
            m_Cookie = cookie;
        }
        #endregion

        #region HttpDownloadFile 下载文件
        public static MemoryStream HttpDownloadFile(string url)
        {
            // 设置参数
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            request.Method = "GET";
            request.CookieContainer = m_Cookie;

            //发送请求并获取相应回应数据
            HttpWebResponse response = request.GetResponse() as HttpWebResponse;
            //直到request.GetResponse()程序才开始向目标网页发送Post请求
            Stream responseStream = response.GetResponseStream();

            //创建写入流
            MemoryStream stream = new MemoryStream();

            byte[] bArr = new byte[1024];
            int size = responseStream.Read(bArr, 0, (int)bArr.Length);
            while (size > 0)
            {
                stream.Write(bArr, 0, size);
                size = responseStream.Read(bArr, 0, (int)bArr.Length);
            }
            stream.Seek(0, SeekOrigin.Begin);
            responseStream.Close();
            return stream;
        }
        #endregion

        #region HttpUploadFile 上传文件
        /// <summary>
        /// Http上传文件
        /// </summary>
        public static string HttpUploadFile(string url, byte[] bArr, string fileName)
        {
            // 设置参数
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            CookieContainer cookieContainer = new CookieContainer();
            request.CookieContainer = cookieContainer;
            request.AllowAutoRedirect = true;
            request.Method = "POST";
            string boundary = DateTime.Now.Ticks.ToString("X"); // 随机分隔线
            request.ContentType = "text/plain;charset=utf-8";
            request.CookieContainer = m_Cookie;

            Stream postStream = request.GetRequestStream();
            postStream.Write(bArr, 0, bArr.Length);
            postStream.Close();

            //发送请求并获取相应回应数据
            HttpWebResponse response = request.GetResponse() as HttpWebResponse;
            //直到request.GetResponse()程序才开始向目标网页发送Post请求
            Stream instream = response.GetResponseStream();
            StreamReader sr = new StreamReader(instream, Encoding.UTF8);
            //返回结果网页（html）代码
            string content = sr.ReadToEnd();
            return content;
        }
        #endregion

        #region HttpPost
        /// <summary>
        /// HttpPost
        /// </summary>
        public static string HttpPost(string url, string data)
        {
            byte[] bArr = ASCIIEncoding.UTF8.GetBytes(data);

            // 设置参数
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            request.CookieContainer = m_Cookie;
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded";
            request.ContentLength = bArr.Length;
            request.UserAgent = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0)";

            Stream postStream = request.GetRequestStream();
            postStream.Write(bArr, 0, bArr.Length);
            postStream.Close();

            //发送请求并获取相应回应数据
            HttpWebResponse response = request.GetResponse() as HttpWebResponse;
            //直到request.GetResponse()程序才开始向目标网页发送Post请求
            Stream responseStream = response.GetResponseStream()