帮忙写下正则表达式~~

[坤哥zzz]

<a onmousedown="return c({'fm':'as','F':'','T':'','title':this.innerHTML,'url':this.href,'p1':0,'y':''})"
href="http://www.baidu.com/baidu.php?url=c-_K00jdJ6JUcgvTqLZBDIVVphmWnWi53-rd9TAOO8EGOmkJOk6aVno7OzXc8oHvgrWw6paF" target="_blank">
只要匹配 href里的url，
例如：http://www.baidu.com/baidu.php?url=c-_K00jdJ6JUcgvTqLZBDIVVphmWnWi53-rd9TAOO8EGOmkJOk6aVno7OzXc8oHvgrWw6paF

[坤哥zzz]

急啊~高手来啊！

[zwb521]

http:\/\/www\.baidu\.com\/baidu\.php.*\d+

更多参考：正则表达式应用--扫描 HREF，提取 URL 信息

[netwar]

href="(.*?)"

[坤哥zzz]

没有人会吗~

[wuhq030710914]

(?<=href=")[^"]+(?=")

[LeoMaya]

<\s*a\s.*\shref\s*=\s*""(?<value>.*?)""\s.*>

[-过客-]

try...

MatchCollection mc = Regex.Matches(yourStr, @"<a(?:(?!href=)[\s\S])*href=(['""]?)(?<url>[^""'\s>]*)\1[^>]*>", RegexOptions.IgnoreCase);
foreach (Match m in mc)
{
    richTextBox2.Text += m.Groups["url"].Value + "\n";
}