求一正则能分析出分页A标签的个数

Question

判断分布的特征是:A标签的文本只有数字如1 2 3 不包含其它任何字母中文或特殊字符
<a href="list.aspx?page=1">1</a>
<a href="list.aspx?page=1">2</a>
<a href="list.aspx?page=1">3</a>
但还有可能是
<a href="list.aspx?page=1"><span>1</span></a>
<a href="list.aspx?page=1"><span>2</span></a>
<a href="list.aspx?page=1"><span>3</span></a>

Answer 1

string pattern=@"(?is)<a[^>]+>((?!</?a)<[^>]+>)*\d((?!</?a)<[^>]+>)*</a>";

Answer 2

Regex reg=new Regex(@"(?i)<a\b[^>]*?>(?:<([^>]*?)>)?\d+(?:</\1>)?</a>");
int c=reg.Matches(yourstr).Count;