<b>this is the test </b> (?<=<(\w+)>)[\s\S]+?(?=</\1>)
2、匹配最外层的（）
a+(b*(c+d))/e+f-(g/(h-i))*j \(((?<Open>\()|(?<-Open>\))|[^()])*(?(Open)(?!))\)
3.匹配a标签
(?is)<a[^>]*?href=(['""]?)(?<url>[^'""\s>]+)\1[^>]*>(?<text>(?:(?!</?a\b).)*)</a>
4.新浪微博
@[\S]+ (https?|ftp)://[\S]+ #.+?#
参考：
