C# HttpWebRequest 绝技 根据URL地址获取网页信息

如果要使用中间的方法的话,可以访问我的帮助类完全免费开源:C# HttpHelper,帮助类,真正的Httprequest请求时无视编码,无视证书,无视Cookie,网页抓取

1.第一招,根据URL地址获取网页信息

   先来看一下代码

get方法

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public static string GetUrltoHtml( string Url, string type)
        {
           
try
            {
                System.Net.WebRequest wReq
= System.Net.WebRequest.Create(Url);
               
// Get the response instance.
                System.Net.WebResponse wResp = wReq.GetResponse();
                System.IO.Stream respStream
= wResp.GetResponseStream();
               
// Dim reader As StreamReader = New StreamReader(respStream)
                using (System.IO.StreamReader reader = new System.IO.StreamReader(respStream, Encoding.GetEncoding(type)))
                {
                    return reader.ReadToEnd();
                }

            }
           
catch (System.Exception ex)
            {
               
// errorMsg = ex.Message;
            }
           
return "" ;
        }
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post方法

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  /// <summary>
       
/// 采用https协议访问网络
       
/// </summary>
       
/// <param name="URL"> url地址 </param>
       
/// <param name="strPostdata"> 发送的数据 </param>
       
/// <returns></returns>
        public string OpenReadWithHttps( string URL, string strPostdata, string strEncoding)
        {
            Encoding encoding
= Encoding.Default;
            HttpWebRequest request
= (HttpWebRequest)WebRequest.Create(URL);
            request.Method
= " post " ;
            request.Accept
= " text/html, application/xhtml+xml, */* " ;
            request.ContentType
= " application/x-www-form-urlencoded " ;
           
byte [] buffer = encoding.GetBytes(strPostdata);
            request.ContentLength
= buffer.Length;
            request.GetRequestStream().Write(buffer,
0 , buffer.Length);
            HttpWebResponse response
= (HttpWebResponse)request.GetResponse();
            using( StreamReader reader
= new StreamReader(response.GetResponseStream(), System.Text.Encoding.GetEncoding(strEncoding)))
              {
                  
return reader.ReadToEnd();
              }
        }
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这招是入门第一式, 特点:

   1.最简单最直观的一种,入门课程。

   2.适应于明文,无需登录,无需任何验证就可以进入的页面。

   3.获取的数据类型为HTML文档。

   4.请求方法为Get/Post

2.第二招,根据URL地址获取需要验证证书才能访问的网页信息

   先来看一下代码

get方法

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  // 回调验证证书问题
        public bool CheckValidationResult( object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
        {  
// 总是接受   
            return true ;
        }

       
/// <summary>
       
/// 传入URL返回网页的html代码
       
/// </summary>
       
/// <param name="Url"> URL </param>
       
/// <returns></returns>
        public string GetUrltoHtml( string Url)
        {
            StringBuilder content
= new StringBuilder();

           
try
            {
               
// 这一句一定要写在创建连接的前面。使用回调的方法进行证书验证。
                ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(CheckValidationResult);

               
// 与指定URL创建HTTP请求
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);

               
// 创建证书文件
                X509Certificate objx509 = new X509Certificate(Application.StartupPath + " \\123.cer " );

               
// 添加到请求里
                request.ClientCertificates.Add(objx509);

               
// 获取对应HTTP请求的响应
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
               
// 获取响应流
                Stream responseStream = response.GetResponseStream();
               
// 对接响应流(以"GBK"字符集)
                StreamReader sReader = new StreamReader(responseStream, Encoding.GetEncoding( " utf-8 " ));
               
// 开始读取数据
                Char[] sReaderBuffer = new Char[ 256 ];
               
int count = sReader.Read(sReaderBuffer, 0 , 256 );
               
while (count > 0 )
                {
                    String tempStr
= new String(sReaderBuffer, 0 , count);
                    content.Append(tempStr);
                    count
= sReader.Read(sReaderBuffer, 0 , 256 );
                }
               
// 读取结束
                sReader.Close();
            }
           
catch (Exception)
            {
                content
= new StringBuilder( " Runtime Error " );
            }

           
return content.ToString();

        }
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post方法

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   // 回调验证证书问题
        public bool CheckValidationResult( object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
        {
           
// 总是接受   
            return true ;
        }

       
/// <summary>
       
/// 采用https协议访问网络
       
/// </summary>
       
/// <param name="URL"> url地址 </param>
       
/// <param name="strPostdata"> 发送的数据 </param>
       
/// <returns></returns>
        public string OpenReadWithHttps( string URL, string strPostdata, string strEncoding)
        {
           
// 这一句一定要写在创建连接的前面。使用回调的方法进行证书验证。
            ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(CheckValidationResult);
            Encoding encoding
= Encoding.Default;
            HttpWebRequest request
= (HttpWebRequest)WebRequest.Create(URL);

           
// 创建证书文件
            X509Certificate objx509 = new X509Certificate(Application.StartupPath + " \\123.cer " );

           
// 加载Cookie
            request.CookieContainer = new CookieContainer();

           
// 添加到请求里
            request.ClientCertificates.Add(objx509);
            request.Method
= " post " ;
            request.Accept
= " text/html, application/xhtml+xml, */* " ;
            request.ContentType
= " application/x-www-form-urlencoded " ;
           
byte [] buffer = encoding.GetBytes(strPostdata);
            request.ContentLength
= buffer.Length;
            request.GetRequestStream().Write(buffer,
0 , buffer.Length);
            HttpWebResponse response
= (HttpWebResponse)request.GetResponse();
            using (StreamReader reader
= new StreamReader(response.GetResponseStream(), System.Text.Encoding.GetEncoding(strEncoding)))
               {
                  
return reader.ReadToEnd();
               }
        }
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这招是学会算是进了大门了,凡是需要验证证书才能进入的页面都可以使用这个方法进入,我使用的是证书回调验证的方式,证书验证是否通过在客户端验证,这样的话我们就可以使用自己定义一个方法来验证了,有的人会说那也不清楚是怎么样验证的啊,其它很简单,代码是自己写的为什么要那么难为自己呢,直接返回一个True不就完了,永远都是验证通过,这样就可以无视证书的存在了, 特点:

   1.入门前的小难题,初级课程。

   2.适应于无需登录,明文但需要验证证书才能访问的页面。

   3.获取的数据类型为HTML文档。

   4.请求方法为Get/Post

3.第三招,根据URL地址获取需要登录才能访问的网页信息

        我们先来分析一下这种类型的网页,需要登录才能访问的网页,其它呢也是一种验证,验证什么呢,验证客户端是否登录,是否具用相应的凭证,需要登录的都要验证SessionID这是每一个需要登录的页面都需要验证的,那我们怎么做的,我们第一步就是要得存在Cookie里面的数据包括SessionID,那怎么得到呢,这个方法很多,使用ID9或者是火狐浏览器很容易就能得到,可以参考我的文章

提供一个网页抓取hao123手机号码归属地的例子   这里面针对ID9有详细的说明。

如果我们得到了登录的Cookie信息之后那个再去访问相应的页面就会非常的简单了,其它说白了就是把本地的Cookie信息在请求的时候捎带过去就行了。

   看代码

get方法

View Code
/// <summary>
       
/// 传入URL返回网页的html代码带有证书的方法
       
/// </summary>
       
/// <param name="Url"> URL </param>
       
/// <returns></returns>
        public string GetUrltoHtml( string Url)
        {
            StringBuilder content
= new StringBuilder();
           
try
            {
               
// 与指定URL创建HTTP请求
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
                request.UserAgent
= " Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0; BOIE9;ZHCN) " ;
                request.Method
= " GET " ;
                request.Accept
= " */* " ;
               
// 如果方法验证网页来源就加上这一句如果不验证那就可以不写了
                request.Referer = " http://sufei.cnblogs.com " ;
                CookieContainer objcok
= new CookieContainer();
                objcok.Add(
new Uri( " http://sufei.cnblogs.com " ), new Cookie( " " , " " ));
                objcok.Add(
new Uri( " http://sufei.cnblogs.com " ), new Cookie( " " , " " ));
                objcok.Add(
new Uri( " http://sufei.cnblogs.com " ), new Cookie( " sidi_sessionid " , " 360A748941D055BEE8C960168C3D4233 " ));
                request.CookieContainer
= objcok;

               
// 不保持连接
                request.KeepAlive = true ;

               
// 获取对应HTTP请求的响应
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();

               
// 获取响应流
                Stream responseStream = response.GetResponseStream();

               
// 对接响应流(以"GBK"字符集)
                StreamReader sReader = new StreamReader(responseStream, Encoding.GetEncoding( " gb2312 " ));

               
// 开始读取数据
                Char[] sReaderBuffer = new Char[ 256 ];
               
int count = sReader.Read(sReaderBuffer, 0 , 256 );
               
while (count > 0 )
                {
                    String tempStr
= new String(sReaderBuffer, 0 , count);
                    content.Append(tempStr);
                    count
= sReader.Read(sReaderBuffer, 0 , 256 );
                }
               
// 读取结束
                sReader.Close();
            }
           
catch (Exception)
            {
                content
= new StringBuilder( " Runtime Error " );
            }

           
return content.ToString();
        }

post方法。

View Code
/// <summary>
       
/// 采用https协议访问网络
       
/// </summary>
       
/// <param name="URL"> url地址 </param>
       
/// <param name="strPostdata"> 发送的数据 </param>
       
/// <returns></returns>
        public string OpenReadWithHttps( string URL, string strPostdata)
        {
            Encoding encoding
= Encoding.Default;
            HttpWebRequest request
= (HttpWebRequest)WebRequest.Create(URL);
            request.Method
= " post " ;
            request.Accept
= " text/html, application/xhtml+xml, */* " ;
            request.ContentType
= " application/x-www-form-urlencoded " ;
            CookieContainer objcok
= new CookieContainer();
            objcok.Add(
new Uri( " http://sufei.cnblogs.com " ), new Cookie( " " , " " ));
            objcok.Add(
new Uri( " http://sufei.cnblogs.com " ), new Cookie( " " , " " ));
            objcok.Add(
new Uri( " http://sufei.cnblogs.com " ), new Cookie( " sidi_sessionid " , " 360A748941D055BEE8C960168C3D4233 " ));
            request.CookieContainer
= objcok;

           
byte [] buffer = encoding.GetBytes(strPostdata);
            request.ContentLength
= buffer.Length;

            request.GetRequestStream().Write(buffer,
0 , buffer.Length);
            HttpWebResponse response
= (HttpWebResponse)request.GetResponse();
            StreamReader reader
= new StreamReader(response.GetResponseStream(), System.Text.Encoding.GetEncoding( " utf-8 " ));
           
return reader.ReadToEnd();

        }

特点:

   1.还算有点水类型的,练习成功后可以小牛一把。

   2.适应于需要登录才能访问的页面。

   3.获取的数据类型为HTML文档。

   4.请求方法为Get/Post

总结一下,其它基本的技能就这几个部分,如果再深入的话那就是基本技能的组合了

比如,

1. 先用Get或者Post方法登录然后取得Cookie再去访问页面得到信息,这种其它也是上面技能的组合,

这里需要以请求后做这样一步

response.Cookies

这就是在你请求后可以得到当次Cookie的方法,直接取得返回给上一个方法使用就行了,上面我们都是自己构造的,在这里直接使用这个Cookie就可以了。

2.如果我们碰到需要登录而且还要验证证书的网页怎么办,其它这个也很简单把我们上面的方法综合 一下就行了

如下代码这里我以Get为例子Post例子也是同样的方法

View Code
  /// <summary>
       
/// 传入URL返回网页的html代码
       
/// </summary>
       
/// <param name="Url"> URL </param>
       
/// <returns></returns>
        public string GetUrltoHtml( string Url)
        {
            StringBuilder content
= new StringBuilder();

           
try
            {
               
// 这一句一定要写在创建连接的前面。使用回调的方法进行证书验证。
                ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(CheckValidationResult);

               
// 与指定URL创建HTTP请求
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);

               
// 创建证书文件
                X509Certificate objx509 = new X509Certificate(Application.StartupPath + " \\123.cer " );

               
// 添加到请求里
                request.ClientCertificates.Add(objx509);

                CookieContainer objcok
= new CookieContainer();
                objcok.Add(
new Uri( " http://www.cnblogs.com " ), new Cookie( " " , " " ));
                objcok.Add(
new Uri( " http://www.cnblogs.com " ), new Cookie( " " , " " ));
                objcok.Add(
new Uri( " http://www.cnblogs.com " ), new Cookie( " sidi_sessionid " , " 360A748941D055BEE8C960168C3D4233 " ));
                request.CookieContainer
= objcok;

               
// 获取对应HTTP请求的响应
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
               
// 获取响应流
                Stream responseStream = response.GetResponseStream();
               
// 对接响应流(以"GBK"字符集)
                StreamReader sReader = new StreamReader(responseStream, Encoding.GetEncoding( " utf-8 " ));
               
// 开始读取数据
                Char[] sReaderBuffer = new Char[ 256 ];
               
int count = sReader.Read(sReaderBuffer, 0 , 256 );
               
while (count > 0 )
                {
                    String tempStr
= new String(sReaderBuffer, 0 , count);
                    content.Append(tempStr);
                    count
= sReader.Read(sReaderBuffer, 0 , 256 );
                }
               
// 读取结束
                sReader.Close();
            }
           
catch (Exception)
            {
                content
= new StringBuilder( " Runtime Error " );
            }

           
return content.ToString();

        }

3.如果我们碰到那种需要验证网页来源的方法应该怎么办呢,这种情况其它是有些程序员会想到你可能会使用程序,自动来获取网页信息,为了防止就使用页面来源来验证,就是说只要不是从他们所在页面或是域名过来的请求就不接受,有的是直接验证来源的IP,这些都可以使用下面一句来进入,这主要是这个地址是可以直接伪造的

          request.Referer = " http://sufei.cnblogs.com " ;

呵呵其它很简单因为这个地址可以直接修改。但是如果服务器上验证的是来源的URL那就完了,我们就得去修改数据包了,这个有点难度暂时不讨论。

4.提供一些与这个例子相配置的方法

    过滤HTML标签的方法

View Code
  /// <summary>
       
/// 过滤html标签
       
/// </summary>
       
/// <param name="strHtml"> html的内容 </param>
       
/// <returns></returns>
        public static string StripHTML( string stringToStrip)
        {
           
// paring using RegEx           //
            stringToStrip = Regex.Replace(stringToStrip, " </p(?:\\s*)>(?:\\s*)<p(?:\\s*)> " , " \n\n " , RegexOptions.IgnoreCase | RegexOptions.Compiled);
            stringToStrip
= Regex.Replace(stringToStrip, " <br(?:\\s*)/> " , " \n " , RegexOptions.IgnoreCase | RegexOptions.Compiled);
            stringToStrip
= Regex.Replace(stringToStrip, " \" " , " '' " , RegexOptions.IgnoreCase | RegexOptions.Compiled);
            stringToStrip
= StripHtmlXmlTags(stringToStrip);
           
return stringToStrip;
        }

       
private static string StripHtmlXmlTags( string content)
        {
           
return Regex.Replace(content, " <[^>]+> " , "" , RegexOptions.IgnoreCase | RegexOptions.Compiled);
        }

     URL转化的方法

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  #region 转化 URL

       
public static string URLDecode( string text)
        {
           
return HttpUtility.UrlDecode(text, Encoding.Default);
        }

       
public static string URLEncode( string text)
        {
           
return HttpUtility.UrlEncode(text, Encoding.Default);
        }

       
#endregion
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提供一个实际例子,这个是使用IP138来查询手机号码归属地的方法,其它在我的上一次文章里都有,在这里我再放上来是方便大家阅读,这方面的技术其它研究起来很有意思,希望大家多提建议,我相信应该还有更多更好,更完善的方法,在这里给大家提供一个参考吧。感谢支持

上例子

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        /// <summary>
       
/// 输入手机号码得到归属地信息
       
/// </summary>
       
/// <param name="number"> 手机号码 </param>
       
/// <returns> 数组类型0为归属地,1卡类型,2区 号,3邮 编 </returns>
        public static string [] getTelldate( string number)
        {
           
try
            {
               
string strSource = GetUrltoHtml( " http://www.ip138.com:8080/search.asp?action=mobile&mobile= " + number.Trim());
               
// 归属地
                strSource = strSource.Substring(strSource.IndexOf(number));
                strSource
= StripHTML(strSource);
                strSource
= strSource.Replace( " \r " , "" );
                strSource
= strSource.Replace( " \n " , "" );
                strSource
= strSource.Replace( " \t " , "" );
                strSource
= strSource.Replace( " &nbsp; " , "" );
                strSource
= strSource.Replace( " --> " , "" );
               
string [] strnumber = strSource.Split( new string [] { " 归属地 " , " 卡类型 " , " 邮 编 " , " 区 号 " , " 更详细 " , " 卡号 " }, StringSplitOptions.RemoveEmptyEntries);
               
string [] strnumber1 = null ;
               
if (strnumber.Length > 4 )
                {
                    strnumber1
= new string [] { strnumber[ 1 ].Trim(), strnumber[ 2 ].Trim(), strnumber[ 3 ].Trim(), strnumber[ 4 ].Trim() };
                }
               
return strnumber1;
            }
           
catch (Exception)
            {
               
return null ;
            }
        }
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这个例子写是不怎么样,些地方是可以简化的,这个接口而且可以直接使用Xml得到,但我在这里的重点是让一些新手看看方法和思路风凉啊,呵呵

第四招,通过Socket访问

------------------------------------------------------------------------------------------------------------

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 ///<summary>
        /// 请求的公共类用来向服务器发送请求
        ///</summary>
        ///<param name="strSMSRequest">发送请求的字符串</param>
        ///<returns>返回的是请求的信息</returns>
        private static string SMSrequest(string strSMSRequest)
        {
            byte[] data = new byte[1024];
            string stringData = null;
            IPHostEntry gist = Dns.GetHostByName("www.110.cn");
            IPAddress ip = gist.AddressList[0];
            //得到IP 
            IPEndPoint ipEnd = new IPEndPoint(ip, 3121);
            //默认80端口号 
            Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            //使用tcp协议 stream类型 
            try
            {
                socket.Connect(ipEnd);
            }
            catch (SocketException ex)
            {
                return "Fail to connect server\r\n" + ex.ToString();
            }
            string path = strSMSRequest.ToString().Trim();
            StringBuilder buf = new StringBuilder();
            //buf.Append("GET ").Append(path).Append(" HTTP/1.0\r\n");
            //buf.Append("Content-Type: application/x-www-form-urlencoded\r\n");
            //buf.Append("\r\n");
            byte[] ms = System.Text.UTF8Encoding.UTF8.GetBytes(buf.ToString());
            //提交请求的信息
            socket.Send(ms);
            //接收返回 
            string strSms = "";
            int recv = 0;
            do
            {
                recv = socket.Receive(data);
                stringData = Encoding.ASCII.GetString(data, 0, recv);
                //如果请求的页面meta中指定了页面的encoding为gb2312则需要使用对应的Encoding来对字节进行转换() 
                strSms = strSms + stringData;
                //strSms += recv.ToString();
            }
            while (recv != 0);
            socket.Shutdown(SocketShutdown.Both);
            socket.Close();
            return strSms;
        }
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