正则表达式替换<img>中src问题
说明如下: 
 有如下字符串: 
  <img   alt= "一键进入教你快速访问Vista网络连接 "   alt=network-adaptors.jpg   src= "http://www.sinaimg.cn/IT/cr/2007/0704/3441139462.jpg "   style= "border:0px   solid   #000; "   _extended= "true ">    
 网页中许多这样的标记,现在的想法是要把其中的src地址改为本地地址,每个文件名应该是不同的,比如“/localhost/web/1.jpg”“/localhost/web/2.jpg”,该怎么弄啊?敬请各位大侠帮忙
------解决方案--------------------src=(\\S*)\\.jpe?g
------解决方案--------------------这样看看,是不是你要的效果   
 string result = Regex.Replace(yourStr, @ "( <img[^> ]*src=([ ' " "]?))[^ ' " "\s> ]*(\2[^> ]*> ) ", new MatchEvaluator(regReplace), RegexOptions.IgnoreCase);     
 int i = 0;  //这个是全局变量 
 private string regReplace(Match m) 
 { 
     i++; 
     return m.Groups[1].Value +  "/localhost/web/ " + i +  ".jpg " + m.Groups[3].Value; 
 }
------解决方案--------------------//处理内嵌图片 
                     if (FormData.settingInfo.ChannelSetting.GetEnbededImage) 
                     { 
                         foreach (ItemInfo item in FormData.reNewInfo.ListItem) 
                         { 
                             //匹配出Description中的Image标签 
                              try 
                             { 
                                 //用于替换每个新闻项描述中的img标签 
                                 item.Description = Regex.Replace(item.Description,  
                                     @ " <img\s*src\s*=\s*[ " " ']?.+\s*.(gif|jpg|bmp|tif|png)\s*.+(\/> | <\/img> ) ", 
                                     new MatchEvaluator(GetNewImageTag),  
                                     RegexOptions.Compiled | RegexOptions.IgnoreCase);                                  
                             } 
                             catch  
                             { } 
                         } 
                     }   
         ///  <summary>  
         /// 返回替换后的image标签 
         ///  </summary>  
         ///  <param name= "match ">  </param>  
         ///  <returns>  </returns>  
         private string GetNewImageTag(Match match) 
         { 
             string matchValue = match.Value;   
             try 
             { 
                 //从image 标签中匹配出URL 
                 matchValue = Regex.Replace(matchValue, 
                                  @ "[a-zA-z]+://[^\s]* ", 
                                  new MatchEvaluator(GetNewImageUrl), 
                                  RegexOptions.Compiled | RegexOptions.IgnoreCase); 
             } 
             catch 
             {               
             }   
             return matchValue; 
         }   
        ///  <summary>  
         /// 联网取图片,并将新生成的图片名返回 
         ///  </summary>  
         ///  <param name= "match ">  </param>  
         ///  <returns>  </returns>  
         private string GetNewImageUrl(Match match) 
         { 
             string matchValue = match.Value; 
             string path = string.Empty; 
             string fileName = string.Empty;   
             try 
             { 
                 //从url中匹配出图片名字的后缀 
                 Regex imageSuffixRegex = new Regex(@ "(\.bmp|\.jpg|\.gif|\.png) ", RegexOptions.Compiled); 
                 Match tempMatch = imageSuffixRegex.Match(matchValue);                   
                 //生成