正则表达式相关：C# 抓取网页类（获取网页中所有信息）

来源：互联网发布：虚拟局域网软件排行编辑：程序博客网时间：2024/05/22 03:49
类的代码：
  1 using System;    2 using System.Data;    3 using System.Configuration;    4 using System.Net;    5 using System.IO;    6 using System.Text;    7 using System.Collections.Generic;    8 using System.Text.RegularExpressions;    9 using System.Threading;   10 using System.Web;   11 using System.Web.UI.MobileControls;   12     /// <summary>   13     /// 网页类   14     /// </summary>   15     public class WebPage   16     {   17         #region 私有成员   18         private Uri m_uri;   //url   19         private List<Link> m_links;    //此网页上的链接   20         private string m_title;        //标题   21         private string m_html;         //HTML代码   22         private string m_outstr;       //网页可输出的纯文本   23         private bool m_good;           //网页是否可用   24         private int m_pagesize;       //网页的大小   25         private static Dictionary<string, CookieContainer> webcookies = new Dictionary<string, CookieContainer>();//存放所有网页的Cookie   26          27         #endregion   28   29         #region 属性   30    31         /// <summary>   32         /// 通过此属性可获得本网页的网址，只读   33         /// </summary>   34         public string URL   35         {   36             get   37             {   38                 return m_uri.AbsoluteUri;   39             }   40         }   41    42         /// <summary>   43         /// 通过此属性可获得本网页的标题，只读   44         /// </summary>   45         public string Title   46         {   47             get   48             {   49                 if (m_title == "")   50                 {   51                     Regex reg = new Regex(@"(?m)<title[^>]*>(?<title>(?:\w|\W)*?)</title[^>]*>", RegexOptions.Multiline | RegexOptions.IgnoreCase);   52                     Match mc = reg.Match(m_html);   53                     if (mc.Success)   54                         m_title = mc.Groups["title"].Value.Trim();   55                 }   56                 return m_title;   57             }   58         }   59         public string M_html   60         {   61             get   62             {   63                 if (m_html == null)   64                 {   65                     m_html = "";   66                 }   67                 return m_html;   68             }   69         }   70         /// <summary>   71         /// 此属性获得本网页的所有链接信息，只读   72         /// </summary>   73         public List<Link> Links   74         {   75             get   76             {   77                 if (m_links.Count == 0) getLinks();   78                 return m_links;   79             }   80         }   81    82    83         /// <summary>   84         /// 此属性返回本网页的全部纯文本信息，只读   85         /// </summary>   86         public string Context   87         {   88             get   89             {   90                 if (m_outstr == "") getContext(Int16.MaxValue);   91                 return m_outstr;   92             }   93         }   94    95         /// <summary>   96         /// 此属性获得本网页的大小   97         /// </summary>   98         public int PageSize   99         {  100             get  101             {  102                 return m_pagesize;  103             }  104         }  105         /// <summary>  106         /// 此属性获得本网页的所有站内链接  107         /// </summary>  108         public List<Link> InsiteLinks  109         {  110             get  111             {  112                 return getSpecialLinksByUrl("^http://" + m_uri.Host, Int16.MaxValue);  113             }  114         }  115   116         /// <summary>  117         /// 此属性表示本网页是否可用  118         /// </summary>  119         public bool IsGood  120         {  121             get  122             {  123                 return m_good;  124             }  125         }  126         /// <summary>  127         /// 此属性表示网页的所在的网站  128         /// </summary>  129         public string Host  130         {  131             get  132             {  133                 return m_uri.Host;  134             }  135         }  136         #endregion  137   138   139         /// <summary>  140         /// 从HTML代码中分析出链接信息  141         /// </summary>  142         /// <returns>List<Link></returns>  143         private List<Link> getLinks()  144         {  145             if (m_links.Count == 0)  146             {  147                 Regex[] regex = new Regex[2];  148                 regex[0] = new Regex(@"<a\shref\s*=""(?<URL>[^""]*).*?>(?<title>[^<]*)</a>", RegexOptions.IgnoreCase | RegexOptions.Singleline);  149                 regex[1] = new Regex("<[i]*frame[^><]+src=(\"|')?(?<url>([^>\"'\\s)])+)(\"|')?[^>]*>", RegexOptions.IgnoreCase);  150   151                 for (int i = 0; i < 2; i++)  152                 {  153                     Match match = regex[i].Match(m_html);  154                     while (match.Success)  155                     {  156                         try  157                         {  158                             string url = HttpUtility.UrlDecode(new Uri(m_uri, match.Groups["URL"].Value).AbsoluteUri);  159   160                             string text = "";  161                             if (i == 0) text = new Regex("(<[^>]+>)|(\\s)|( )|&|\"", RegexOptions.Multiline | RegexOptions.IgnoreCase).Replace(match.Groups["text"].Value, "");  162   163                             Link link = new Link();  164                             link.Text = text;  165                             link.NavigateUrl = url;  166   167                             m_links.Add(link);  168                         }  169                         catch (Exception ex) { Console.WriteLine(ex.Message); };  170                         match = match.NextMatch();  171                     }  172                 }  173             }  174             return m_links;  175         }  176         /// <summary>  177         /// 此私有方法从一段HTML文本中提取出一定字数的纯文本  178         /// </summary>  179         /// <param name="instr">HTML代码</param>  180         /// <param name="firstN">提取从头数多少个字</param>  181         /// <param name="withLink">是否要链接里面的字</param>  182         /// <returns>纯文本</returns>  183         private string getFirstNchar(string instr, int firstN, bool withLink)  184         {  185             if (m_outstr == "")  186             {  187                 m_outstr = instr.Clone() as string;  188                 m_outstr = new Regex(@"(?m)<script[^>]*>(\w|\W)*?</script[^>]*>", RegexOptions.Multiline | RegexOptions.IgnoreCase).Replace(m_outstr, "");  189                 m_outstr = new Regex(@"(?m)<style[^>]*>(\w|\W)*?</style[^>]*>", RegexOptions.Multiline | RegexOptions.IgnoreCase).Replace(m_outstr, "");  190                 m_outstr = new Regex(@"(?m)<select[^>]*>(\w|\W)*?</select[^>]*>", RegexOptions.Multiline | RegexOptions.IgnoreCase).Replace(m_outstr, "");  191                 if (!withLink) m_outstr = new Regex(@"(?m)<a[^>]*>(\w|\W)*?</a[^>]*>", RegexOptions.Multiline | RegexOptions.IgnoreCase).Replace(m_outstr, "");  192                 Regex objReg = new System.Text.RegularExpressions.Regex("(<[^>]+?>)| ", RegexOptions.Multiline | RegexOptions.IgnoreCase);  193                 m_outstr = objReg.Replace(m_outstr, "");  194                 Regex objReg2 = new System.Text.RegularExpressions.Regex("(\\s)+", RegexOptions.Multiline | RegexOptions.IgnoreCase);  195                 m_outstr = objReg2.Replace(m_outstr, " ");  196   197             }  198             return m_outstr.Length > firstN ? m_outstr.Substring(0, firstN) : m_outstr;  199         }  200  201  202         #region 公有文法  203         /// <summary>  204         /// 此公有方法提取网页中一定字数的纯文本，包括链接文字  205         /// </summary>  206         /// <param name="firstN">字数</param>  207         /// <returns></returns>  208         public string getContext(int firstN)  209         {  210             return getFirstNchar(m_html, firstN, true);  211         }  212   213         /// <summary>  214         /// 此公有方法从本网页的链接中提取一定数量的链接，该链接的URL满足某正则式  215         /// </summary>  216         /// <param name="pattern">正则式</param>  217         /// <param name="count">返回的链接的个数</param>  218         /// <returns>List<Link></returns>  219         public List<Link> getSpecialLinksByUrl(string pattern, int count)  220         {  221             if (m_links.Count == 0) getLinks();  222             List<Link> SpecialLinks = new List<Link>();  223             List<Link>.Enumerator i;  224             i = m_links.GetEnumerator();  225             int cnt = 0;  226             while (i.MoveNext() && cnt < count)  227             {  228                 if (new Regex(pattern, RegexOptions.Multiline | RegexOptions.IgnoreCase).Match(i.Current.NavigateUrl).Success)  229                 {  230                     SpecialLinks.Add(i.Current);  231                     cnt++;  232                 }  233             }  234             return SpecialLinks;  235         }  236   237         /// <summary>  238         /// 此公有方法从本网页的链接中提取一定数量的链接，该链接的文字满足某正则式  239         /// </summary>  240         /// <param name="pattern">正则式</param>  241         /// <param name="count">返回的链接的个数</param>  242         /// <returns>List<Link></returns>  243         public List<Link> getSpecialLinksByText(string pattern, int count)  244         {  245             if (m_links.Count == 0) getLinks();  246             List<Link> SpecialLinks = new List<Link>();  247             List<Link>.Enumerator i;  248             i = m_links.GetEnumerator();  249             int cnt = 0;  250             while (i.MoveNext() && cnt < count)  251             {  252                 if (new Regex(pattern, RegexOptions.Multiline | RegexOptions.IgnoreCase).Match(i.Current.Text).Success)  253                 {  254                     SpecialLinks.Add(i.Current);  255                     cnt++;  256                 }  257             }  258             return SpecialLinks;  259         }  260   261         /// <summary>  262         /// 这公有方法提取本网页的纯文本中满足某正则式的文字  by 何问起263         /// </summary>  264         /// <param name="pattern">正则式</param>  265         /// <returns>返回文字</returns>  266         public string getSpecialWords(string pattern)  267         {  268             if (m_outstr == "") getContext(Int16.MaxValue);  269             Regex regex = new Regex(pattern, RegexOptions.Multiline | RegexOptions.IgnoreCase);  270             Match mc = regex.Match(m_outstr);  271             if (mc.Success)  272                 return mc.Groups[1].Value;  273             return string.Empty;  274         }  275         #endregion  276  277         #region 构造函数  278   279         private void Init(string _url)  280         {  281             try  282             {  283                 m_uri = new Uri(_url);  284                 m_links = new List<Link>();  285                 m_html = "";  286                 m_outstr = "";  287                 m_title = "";  288                 m_good = true;  289                 if (_url.EndsWith(".rar") || _url.EndsWith(".dat") || _url.EndsWith(".msi"))  290                 {  291                     m_good = false;  292                     return;  293                 }  294                 HttpWebRequest rqst = (HttpWebRequest)WebRequest.Create(m_uri);  295                 rqst.AllowAutoRedirect = true;  296                 rqst.MaximumAutomaticRedirections = 3;  297                 rqst.UserAgent = "Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)";  298                 rqst.KeepAlive = true;  299                 rqst.Timeout = 10000;  300                 lock (WebPage.webcookies)  301                 {  302                     if (WebPage.webcookies.ContainsKey(m_uri.Host))  303                         rqst.CookieContainer = WebPage.webcookies[m_uri.Host];  304                     else  305                     {  306                         CookieContainer cc = new CookieContainer();  307                         WebPage.webcookies[m_uri.Host] = cc;  308                         rqst.CookieContainer = cc;  309                     }  310                 }  311                 HttpWebResponse rsps = (HttpWebResponse)rqst.GetResponse();  312                 Stream sm = rsps.GetResponseStream();  313                 if (!rsps.ContentType.ToLower().StartsWith("text/") || rsps.ContentLength > 1 << 22)  314                 {  315                     rsps.Close();  316                     m_good = false;  317                     return;  318                 }  319                 Encoding cding = System.Text.Encoding.Default;  320                 string contenttype = rsps.ContentType.ToLower();  321                 int ix = contenttype.IndexOf("charset=");  322                 if (ix != -1)  323                 {  324                     try  325                     {  326                         cding = System.Text.Encoding.GetEncoding(rsps.ContentType.Substring(ix + "charset".Length + 1));  327                     }  328                     catch  329                     {  330                         cding = Encoding.Default;  331                     }  332                      333                     //该处视情况而定 有的需要解码  334                     //m_html = HttpUtility.HtmlDecode(new StreamReader(sm, cding).ReadToEnd());  335                     m_html = new StreamReader(sm, cding).ReadToEnd();  336                       337                 }  338                 else  339                 {  340                   //该处视情况而定 有的需要解码  341                    //m_html = HttpUtility.HtmlDecode(new StreamReader(sm, cding).ReadToEnd());  342                       343                     m_html = new StreamReader(sm, cding).ReadToEnd();  344                     Regex regex = new Regex("charset=(?<cding>[^=]+)?\"", RegexOptions.IgnoreCase);  345                     string strcding = regex.Match(m_html).Groups["cding"].Value;  346                     try  347                     {  348                         cding = Encoding.GetEncoding(strcding);  349                     }  350                     catch  351                     {  352                         cding = Encoding.Default;  353                     }  354                     byte[] bytes = Encoding.Default.GetBytes(m_html.ToCharArray());  355                     m_html = cding.GetString(bytes);  356                     if (m_html.Split('?').Length > 100)  357                     {  358                         m_html = Encoding.Default.GetString(bytes);  359                     }  360                 }  361                 m_pagesize = m_html.Length;  362                 m_uri = rsps.ResponseUri;  363                 rsps.Close();  364             }  365             catch (Exception ex)  366             {  367                  368             }  369         }  370         public WebPage(string _url)  371         {  372             string uurl = "";  373             try  374             {  375                 uurl = Uri.UnescapeDataString(_url);  376                 _url = uurl;  377             }  378             catch { };  379             Init(_url);  380         }  381         #endregion  382     }
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