/// <summary>

    /// 获取源代码

    /// </summary>

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

    /// <returns></returns>

    public static string GetHtml(string url, Encoding encoding)

    {

        HttpWebRequest request = null;

        HttpWebResponse response = null;

        StreamReader reader = null;

        try

        {

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

            request.Timeout = ;

            request.AllowAutoRedirect = false;

            response = (HttpWebResponse)request.GetResponse();

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

            {

                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;

    }

    public static string GetEncoding(string url)

    {

        HttpWebRequest request = null;

        HttpWebResponse response = null;

        StreamReader reader = null;

        try

        {

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

            request.Timeout = ;

            request.AllowAutoRedirect = false;

            response = (HttpWebResponse)request.GetResponse();

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

            {

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

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

                else

                    reader = new StreamReader(response.GetResponseStream(), Encoding.ASCII);

                string html = reader.ReadToEnd();

                Regex reg_charset = new Regex(@"charset\b\s*=\s*(?<charset>[^""]*)");

                if (reg_charset.IsMatch(html))

                {

                    return reg_charset.Match(html).Groups["charset"].Value;

                }

                else if (response.CharacterSet != string.Empty)

                {

                    return response.CharacterSet;

                }

                else

                    return Encoding.Default.BodyName;

            }

        }

        catch

        {

        }

        finally

        {

            if (response != null)

            {

                response.Close();

                response = null;

            }

            if (reader != null)

                reader.Close();

            if (request != null)

                request = null;

        }

    }

 using System;

 using System.Net;

 using System.Text;

 using System.Text.RegularExpressions; 

 class Program

 {

   // 获取网页的HTML内容，根据网页的charset自动判断Encoding

   static string GetHtml(string url)

   {

     return GetHtml(url, null);

   } 

   // 获取网页的HTML内容，指定Encoding

   static string GetHtml(string url, Encoding encoding)

   {

     byte[] buf = new WebClient().DownloadData(url);

     if (encoding != null) return encoding.GetString(buf);

     string html = Encoding.UTF8.GetString(buf);

     encoding = GetEncoding(html);

     if (encoding == null || encoding == Encoding.UTF8) return html;

     return encoding.GetString(buf);

   } 

   // 根据网页的HTML内容提取网页的Encoding

   static Encoding GetEncoding(string html)

   {

     string pattern = @"(?i)\bcharset=(? <charset>[-a-zA-Z_0-9]+)";

     string charset = Regex.Match(html, pattern).Groups["charset"].Value;

     try { return Encoding.GetEncoding(charset); }

     catch (ArgumentException) { return null; }

   } 

   // 根据网页的HTML内容提取网页的Title

   static string GetTitle(string html)

   {

     string pattern = @"(?si) <title(?:\s+(?:""[^""]*""|'[^']*'|[^""'>])*)?>(? <title>.*?) </title>";

     return Regex.Match(html, pattern).Groups["title"].Value.Trim();

   } 

   // 打印网页的Encoding和Title

   static void PrintEncodingAndTitle(string url)

   {

     string html = GetHtml(url);

     Console.WriteLine("[{0}] [{1}]", GetEncoding(html), GetTitle(html));

   } 

   // 程序入口

   static void Main()

   {

     PrintEncodingAndTitle("http://www.msdn.net/");

     PrintEncodingAndTitle("http://www.cnblogs.com/");

     PrintEncodingAndTitle("http://www.cnblogs.com/skyiv/");

     PrintEncodingAndTitle("http://www.csdn.net/");

     PrintEncodingAndTitle("http://news.163.com/");

   }

 }

 /* 程序输出：

 [] [MSDN: Microsoft Developer Network]

 [System.Text.UTF8Encoding] [博客园 - 程序员的网上家园]

 [System.Text.UTF8Encoding] [空间/IV - 博客园]

 [System.Text.UTF8Encoding] [CSDN.NET - 中国最大的IT技术社区，为IT专业技术人员提供最全面的信息传播和服务平台]

 [System.Text.DBCSCodePageEncoding] [新闻中心_网易新闻]

 */