怎么用正则表达式获取网页中的特定字符串

[eric_chen1988]

要获取 http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6574869 这个网页中的字符串“Performance Analysis and Optimization for Energy-Efficient Cooperative Transmission in Random Wireless Sensor Network”

自己C#写了一段程序，但总是获取不到任何字符，请大家帮忙看一下，谢谢！

 
       //获取指定字符串
        private string GetPaperName(string strHTML)
        {
           Regex re = new Regex("(?<=<meta name=\"citation_title\" content=\").*\b");
           Match ma = re.Match(strHTML);
           string strName = ma.Value.ToString();
           return strName;
        }

        //获取网页源码
        private string GetHttpWebRequest(string url)
        {
            Uri uri = new Uri(url);
            HttpWebRequest myReq = (HttpWebRequest)WebRequest.Create(uri);
            myReq.UserAgent = "User-Agent:Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705";
            myReq.Accept = "*/*";
            myReq.KeepAlive = true;
            myReq.Headers.Add("Accept-Language", "zh-cn,en-us;q=0.5");
            HttpWebResponse result = (HttpWebResponse)myReq.GetResponse();
            Stream receviceStream = result.GetResponseStream();
            StreamReader readerOfStream = new StreamReader(receviceStream, System.Text.Encoding.GetEncoding("utf-8"));
            string strHTML = readerOfStream.ReadToEnd();
            readerOfStream.Close();
            receviceStream.Close();
            result.Close();
            return strHTML;
        } 

[q107770540]

//获取指定字符串
        private string GetPaperName(string strHTML)
        {
           Regex re = new Regex("(?<=<meta name=\"citation_title\" content=\").*?(?=\")");
           Match ma = re.Match(strHTML);
          
           return ma.Success?ma.Value:"";
        }

[eric_chen1988]

引用 1 楼 q107770540 的回复:

//获取指定字符串
        private string GetPaperName(string strHTML)
        {
           Regex re = new Regex("(?<=<meta name=\"citation_title\" content=\").*?(?=\")");
           Match ma = re.Match(strHTML);
          
           return ma.Success?ma.Value:"";
        }

搞定了，谢谢~~ 斑竹能解释下我那为什么错了，我用下载的一个正则表达式测试工具测试能得到正确结果，但程序中又不对了。