用正则表达式从网页里面提取视频地址

//用正则表达式从网页里面提取视频地址

//获得一个页面地址，拿到页面html，然后正则表达式去匹配视频地址

//详细的看注释吧。

　1///<summary>
  2 /// 网页视频处理类
  3 ///</summary>
  6 ///<history>
  7 /// 
  8 ///</history>
  9     public class WebVideo
 10     {
 11         ///<summary>
 12 /// 优酷、酷6、土豆等视频页面地址
 13 ///</summary>
 14         private string _pageUrl;
 15         
 16         ///<summary>
 17 /// 是否启用页面压缩
 18 ///</summary>
 19         private bool _isCompressed;
 20 
 21         ///<summary>
 22 /// 网站
 23 ///</summary>
 24         private VideoSite _site;
 25 
 26 
 27         public WebVideo ()
 28         {
 29             // TODO: Complete member initialization
 30         }
 31 
 32 
 33         ///<summary>
 34 /// 实例化WebVideo类
 35 ///</summary>
 36 ///<param name="pageUrl">视频页面地址</param>
 37 ///<param name="isCompressed">获取页面时是否启用压缩</param>
 38         public WebVideo ( string pageUrl, bool isCompressed )
 39         {
 40             // TODO: Complete member initialization
 41             this._pageUrl = pageUrl.Trim();
 42             this._isCompressed = isCompressed;
 43             this._site = this.GetSite(_pageUrl);
 44         }
 45 
 46         
 47         ///<summary>
 48 /// 根据Url地址得到网页的html源码
 49 /// (使用gzip，deflate压缩，延迟低)
 50 ///</summary>
 51 ///<param name="Url"></param>
 52 ///<returns></returns>
 53         public string GetWebContent ( string Url )
 54         {
 55             string strResult = "";
 56             try
 57             {
 58                 Stream decompressedStream = null;
 59                 //声明一个HttpWebRequest请求
 60                 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
 61                 request.Accept = "*/*";
 62                 request.Headers.Set("Pragma", "no-cache");
 63                 //设置连接超时时间
 64                 request.Timeout = 9000;
 65                 request.UserAgent = "TaoCaiSpider1.0  Kevin-Gu's spider";
 66                 request.Headers.Add("Accept-Encoding", "gzip,deflate");
 67 
 68                 HttpWebResponse response = (HttpWebResponse)request.GetResponse();
 69 
 70                 string compressMode = response.ContentEncoding.ToLower();
 71                 Console.WriteLine(compressMode);
 72 
 73                 if (compressMode == "gzip")
 74                 {
 75                     decompressedStream 
 76                         = new GZipStream(response.GetResponseStream(), CompressionMode.Decompress);
 77                 }
 78                 else if (compressMode == "deflate")
 79                 {
 80                     decompressedStream
 81                        = new DeflateStream(response.GetResponseStream(), CompressionMode.Decompress);
 82                 }
 83                 else
 84                 {
 85                     // 貌似只有优酷启用了页面压缩。。。
 86                     decompressedStream = response.GetResponseStream();
 87                 }
 88 
 89                 Encoding encode = Encoding.GetEncoding(response.CharacterSet);
 90                 using (StreamReader streamReader = new StreamReader(decompressedStream, encode))
 91                 {
 92                     strResult = streamReader.ReadToEnd();
 93                 }
 94             }
 95             catch (Exception ex)
 96             {
 97                 Console.WriteLine("error occored:" + ex.Message);
 98             }
 99             return strResult;
100         }
101 
134 
135
167 
168 
169         ///<summary>
170 /// 使用正则表达式匹配获取视频文件地址
171 ///</summary>
172 ///<param name="htmlContent"></param>
173 ///<returns></returns>
174         public string GetVideoFileUrl (string htmlContent)
175         {
176             string[] rgxArr =new string[]{ 
177                 @"http://player\.youku\.com/player\.php/sid/[\w]{13}/v\.swf", //优酷的文件地址正则
178                 @"http://player\.ku6\.com/refer/[\w]{16}/v\.swf",
179                 @"http://js\.tudouui\.com/bin/player_online/[\w]+\.swf"
180             };
193 
194             Regex rgx;
195 
196             // 使用不同的正则表达式来匹配视频文件地址
197             switch (_site)
198             {
199                 case VideoSite.YouKu:
200                     rgx = new Regex(rgxArr[0]);
201                     if (rgx.IsMatch(htmlContent))
202                     {
203                         return rgx.Match(htmlContent).ToString();
204                     }
205                     break;
206                 case VideoSite.TuDou:
207                     rgx = new Regex(rgxArr[2]);
208                     if (rgx.IsMatch(htmlContent))
209                     {
210                         return rgx.Match(htmlContent).ToString();
211                     }
212                     break;
213                 case VideoSite.Ku6:
214                     rgx = new Regex(rgxArr[1]);
215                     if (rgx.IsMatch(htmlContent))
216                     {
217                         return rgx.Match(htmlContent).ToString();
218                     }
219                     break;
220                 default:
221                     break;
222             }
223            
224             return string.Empty;
225         }
226 
227 
228         ///<summary>
229 /// 获得视频网页中视频文件地址
230 ///</summary>
231 ///<returns></returns>
232         public string GetVideoUrl ()
233         {
234             string videoUrl = string.Empty;
235            if (_isCompressed)
236            {
237                string html = this.GetWebContent(_pageUrl);
238                videoUrl = this.GetVideoFileUrl(html);
239            }
240            else
241            {
242                string html = this.GetHtmlWithoutCompress(_pageUrl);
243                videoUrl = this.GetVideoFileUrl(html);
244            }
245            return videoUrl;
246         }
247 
248 
258      
259     }//end class
260 
261 
262     ///<summary>
263 /// 视频网站枚举
264 ///</summary>
265     public enum VideoSite
266     { 
267         YouKu=0,
268         Ku6=1,
269         TuDou=2,
270     };