记录自己写的:string d = @"(?is)<d\s.*?>(.*?)</d>";
string image = @"(?is)<image.*?/>";
string imageid = "<d[^>]*?name=(['\"\"]?)(?<name>[^'\"\"\\s>]+)\\1[^>]*>";
string tdpatterns = @"(?is)<td[^>]*>(?<pvalue>(?><td[^>]*>(?<o>)|</td>(?<-o>)|(?:(?!</?td\b).)*)*(?(o)(?!)))</td>";