讲解:http://blog.csdn.net/zm2714/article/details/7946437
1.匹配嵌套的div:
<div[^>]*>[^<>]*(((?'Open'<div[^>]*>)[^<>]*)+((?'-Open'</div>)[^<>]*)+)*(?(Open)(?!))</div>
2.匹配类似这么的jsonhttp://rate.taobao.com/feedRateList.htm?callback=jsonp_reviews_list&userNumId=88442756&auctionNumId=27006028977&siteID=4¤tPageNum=1&rateType=&orderType=sort_weight&showContent=1&attribute=
\{\042append\042((?<o>\{)|(?<-o>\})|[^{}]+)*(?(o)(?!))\}