C#正则表达式匹配HTML代码

Question

一个HTML页面中有下面这些内容：

<div class="name_wrap"><a href="/home/main?un=%B0%AC%C5%B7%C6%D0%CC%E1" class="user_name" title="艾欧菩提">艾欧菩提</a><span class="forum-level-bawu bawu-info-lv1"></span></div></span>        <span class="member "><a href="/home/main?un=%C4%C7%D0%A9%C4%EA%D1%E6%C5%F1%CF%CD%D5%DF" class="avatar"><img src="http://tb.himg.baidu.com/sys/portrait/item/9e12c4c7d0a9c4ead1e6c5f1cfcdd5df9282" alt="头像"></a><div class="name_wrap"><a href="/home/main?un=%C4%C7%D0%A9%C4%EA%D1%E6%C5%F1%CF%CD%D5%DF" class="user_name" title="那些年焰篷贤者">那些年焰篷贤者</a><span class="forum-level-bawu bawu-info-lv1"></span></div></span>        <span class="member "><a href="/home/main?un=xooo1019H" class="avatar"><img src="http://tb.himg.baidu.com/sys/portrait/item/5ed6786f6f6f31303139483abc" alt="头像"></a><div class="name_wrap"><a href="/home/main?un=xooo1019H" class="user_name" title="xooo1019H">xooo1019H</a><span class="forum-level-bawu bawu-info-lv1"></span></div></span>        <span class="member "><a href="/home/main?un=%D4%DD%BB%BA%C5%D0%B6%CFkkM" class="avatar"><img src="http://tb.himg.baidu.com/sys/portrait/item/5e1cd4ddbbbac5d0b6cf6b6b4d8fbc" alt="头像"></a><div class="name_wrap"><a href="/home/main?un=%D4%DD%BB%BA%C5%D0%B6%CFkkM" class="user_name" title="暂缓判断kkM">暂缓判断kkM</a><span class="forum-level-bawu bawu-info-lv1"></span></div></span>        <span class="member "><a href="/home/main?un=%C3%D1%B9%C3%BC%B7%D1%B9%C9%D2" class="avatar"><img src="http://tb.himg.baidu.com/sys/portrait/item/6aa6c3d1b9c3bcb7d1b9c9d289aa" alt="头像"></a><div class="name_wrap"><a href="/home/main?un=%C3%D1%B9%C3%BC%B7%D1%B9%C9%D2" class="user_name" title="醚姑挤压梢">醚姑挤压梢</a><span class="forum-level-bawu bawu-info-lv1"></span></div></span>        <span class="member "><a href="/home/main?un=%D3%D0%B0%AE%D0%A1%B0%A2%B2%A93A" class="avatar"><img src="http://tb.himg.baidu.com/sys/portrait/item/d720d3d0b0aed0a1b0a2b2a9334166bc" alt="头像"></a><div class="name_wrap"><a href="/home/main?un=%D3%D0%B0%AE%D0%A1%B0%A2%B2%A93A" class="user_name" title="有爱小阿博3A">有爱小阿博3A</a>

我想通过C#的正则表达式，读取里面所有class为"user_name"的a标签的title属性，正则表达式该怎么写？

Answer 1

var html = "你的html";
var reg = new Regexp(@"class\=""user_name""[^<>]+title\=""(?<value>.+?)""");

var match = reg.Match(html);

string title = match.Groups["value"].Value

正则虽然可以实现
但是建议你使用xpath 更方便

Answer 2

class="user_name" title="(.+?)"

Answer 3

(?<=<a [^>]*?class="user_name" title=")[^"]*

匹配结果如下：