[散分分享代码]HttpWebRequest获取网页源代码时自动识别网页编码

       /// <summary>

        /// 获取源代码

        /// </summary>

        /// <param name="url"></param>

        /// <returns></returns>

        static string GetHtml(string url, Encoding encoding)

        {

            HttpWebRequest request = null;

            HttpWebResponse response = null;

            StreamReader reader = null;

            try

            {

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

                request.Timeout = 20000;

                request.AllowAutoRedirect = false;



                response = (HttpWebResponse)request.GetResponse();

                if (response.StatusCode == HttpStatusCode.OK && response.ContentLength < 1024 * 1024)

                {

                    if (response.ContentEncoding != null && response.ContentEncoding.Equals("gzip", StringComparison.InvariantCultureIgnoreCase))

                        reader = new StreamReader(new GZipStream(response.GetResponseStream(), CompressionMode.Decompress), encoding);

                    else

                        reader = new StreamReader(response.GetResponseStream(), encoding);

                    string html = reader.ReadToEnd();



                    return html;

                }

            }

            catch

            {

            }

            finally

            {



                if (response != null)

                {

                    response.Close();

                    response = null;

                }

                if (reader != null)

                    reader.Close();



                if (request != null)

                    request = null;



            }



            return string.Empty;

        }