c#访问HTTP

来自：http://hi.baidu.com/latte88/blog/item/d14a691bf5a5eefdae513304.html
程序介绍：一个HTTP/HTTPS进行GET/POST访问的类，并可根据GZip编码对网页进行解压。使用方法很简单，这里就不介绍了。自己看源码。

using System;
using System.IO;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System.Security.Cryptography.X509Certificates;
using ICSharpCode.SharpZipLib.GZip;

namespace HttpRequest
{
     /*
     * 程序设计：月亮太阳
     * E-mail：[e-mail]
     * QQ:548317
     * */

     /// <summary>
     /// HTTP/HTTPS资源的请求。
     /// </summary>
     public class HttpRequest
     {       
         // 保持Cookie为同一Cookie值。       
         protected CookieContainer craboCookie = new CookieContainer();

         protected string __Uri__                 = null;         // 标识 Internet 资源的 URI

         protected string __Referer__             = null;         // 标识 Internet 资源请求的 Referer       

         protected string __Headers__             = null;         // 标识 Internet 资源请求的 Header

         // 标识 Internet 资源请求的 Accept
         protected string __Accept__                 = "image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*";

         protected string __Method__                 = null;         // 标识 Internet 资源请求的 Method

         protected string __Data__                 = null;         // POST请求时的数据

         protected string __CharacterSet__         = null;         // 响应的字符集

         protected HttpStatusCode __StatusCode__     ;         // 响应状态

         protected StringBuilder __Html_Text__     = new StringBuilder();

         public HttpRequest()
         {
             //
             // TODO: 在此处添加构造函数逻辑
             //
             __CharacterSet__ = "GB2312";
         }

         /// <summary>
         /// 对 Internet 资源发起GET请求
         /// </summary>
         /// <param name="requestUriString">标识 Internet 资源的 URI</param>
         /// <param name="requestReferer">标识 Internet 资源请求的 Referer</param>
         public bool OpenRequest(string requestUriString, string requestReferer)
         {
             __Uri__ = requestUriString;
             __Referer__ = requestReferer;
             __Method__ = "GET";
             return OpenRequest();
         }

         /// <summary>
         /// 对 Internet 资源发起GET请求
         /// </summary>
         /// <param name="requestUriString">标识 Internet 资源的 URI</param>
         /// <param name="requestReferer">标识 Internet 资源请求的 Referer</param>
         /// <param name="requestMethod">标识 Internet 资源请求的 Post 数据</param>
         public bool OpenRequest(string requestUriString, string requestReferer, string requestData)
         {
             __Uri__ = requestUriString;
             __Referer__ = requestReferer;
             __Data__ = requestData;
             __Method__ = "POST";

             return OpenRequest();
         }

         /// <summary>
         /// 对 Internet 资源发起请求
         /// </summary>
         /// <returns></returns>
         private bool OpenRequest()
         {
             // 清空已保留代码
             __Html_Text__.Remove(0, __Html_Text__.Length);

             // 创建 HttpWebRequest 实例
             HttpWebRequest Request = (HttpWebRequest)WebRequest.Create(__Uri__);

             // 设置跟随重定向
             Request.AllowAutoRedirect = true;

             #region 判断Uri资源类型
             {
                 Regex __RegexUri_ = new Regex("^https://", RegexOptions.IgnoreCase);
                 if(__RegexUri_.IsMatch(__Uri__))
                     ServicePointManager.CertificatePolicy = new TrustAllCertificatePolicy();
             }
             #endregion

             Request.Timeout = 10000;
             Request.Method = __Method__;
             Request.Accept = __Accept__;
             Request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; Maxthon; .NET CLR 1.1.4322); Http STdns";
             Request.CookieContainer = craboCookie;
             Request.Referer = __Referer__;
             Request.Method = __Method__;
             if(__Method__=="POST")
             {
                 #region 请求为POST
                 Request.ContentType = "application/x-www-form-urlencoded";
                 byte[] Bytes = Encoding.GetEncoding(CharacterSet).GetBytes(__Data__);
                 Request.ContentLength = Bytes.Length;
                 using(Stream writer = Request.GetRequestStream())
                 {
                     writer.Write(Bytes, 0, Bytes.Length);
                     writer.Close();
                 }
                 #endregion
             }

             #region 读取返回数据
             // 设置返回值变量
             bool bResult = true;
             try
             {
                 HttpWebResponse Response = (HttpWebResponse)Request.GetResponse();


                 // 获取状态值
                 __StatusCode__ = Response.StatusCode;

                 if(__StatusCode__==HttpStatusCode.OK)
                 {               
                     // 判断页面编码
                     string ContentEncoding = Response.ContentEncoding.ToLower();
                     switch(ContentEncoding)
                     {
                         case "gzip":
                             using(Stream reader = new GZipInputStream(Response.GetResponseStream()))
                             {
                                 MemoryStream ms = new MemoryStream();
                                 int nSize = 4096;
                                 byte[] writeData = new byte[nSize];
                                 while(true)
                                 {
                                     try
                                     {
                                         nSize = reader.Read(writeData, 0, nSize);
                                         if(nSize>0)
                                             ms.Write(writeData, 0, nSize);
                                         else
                                             break;
                                     }
                                     catch(GZipException)
                                     {
                                         break;
                                     }
                                 }
                                 reader.Close();
                                 __Html_Text__.Append(Encoding.GetEncoding(CharacterSet).GetString(ms.GetBuffer()));
                             }
                             break;
                         default:
                             using(Stream reader = Response.GetResponseStream())
                             {
                                 StreamReader sr = new StreamReader(reader, Encoding.GetEncoding(CharacterSet));
                                 __Html_Text__.Append(sr.ReadToEnd());
                                 sr.Close();
                                 reader.Close();
                             }
                             break;
                     }
                 }
                 else
                     bResult = false;
             }
             catch(Exception pEx)
             {
                 __Html_Text__.Append(pEx.Message);
                 return false;
             }

             #endregion

             return bResult;
         }

         /// <summary>
         /// 获取或设置 Uri 资源字符集
         /// </summary>
         public string CharacterSet
         {
             get
             {
                 return __CharacterSet__;
             }
             set
             {
                 __CharacterSet__ = value;
             }
         }

         /// <summary>
         /// 获取或设置 Uri 资源标识
         /// </summary>
         public string RequestUriString
         {
             get
             {
                 return __Uri__;
             }
             set
             {
                 __Uri__ = value;
             }
         }

         /// <summary>
         /// 获取或设置 Uri 资源请求 Accept
         /// </summary>
         public string Accept
         {
             get
             {
                 return __Accept__;
             }
             set
             {
                 __Accept__ = value;
             }
         }

         public string HtmlDocument
         {
             get
             {
                 return __Html_Text__.ToString();
             }
         }
     }

     /// <summary>
     /// 当 Uri 资源为 HTTPS 时，忽略证书。
     /// </summary>
     public class TrustAllCertificatePolicy : ICertificatePolicy
     {
         public TrustAllCertificatePolicy()
         {
             //
             // TODO: 在此处添加构造函数逻辑
             //
         }

         public bool CheckValidationResult(ServicePoint _ServicePoint_, X509Certificate _Cert_, WebRequest _WebRequest_, int _Problem_)
         {
             return true;
         }
     }
}