C#用正则表达式 获取标签的属性或值

整理两个 在C#中，用正则表达式 获取网页源代码标签的属性或值的方法 ：

1、获取标签中的值： string str="<a href="www.csdn.net" class="main" >CSDN</a>" 结果：CSDN

 调用例子：string name=GetTitleContent(str,"a");

/// <summary>
/// 获取字符中指定标签的值
/// </summary>
/// <param name="str">字符串</param>
/// <param name="title">标签</param>
/// <returns>值</returns>
public static string GetTitleContent(string str, string title)
{
string tmpStr = string.Format("<{0}[^>]*?>(?<Text>[^<]*)</{1}>", title, title); //获取<title>之间内容

Match TitleMatch = Regex.Match(str, tmpStr, RegexOptions.IgnoreCase);

string result = TitleMatch.Groups["Text"].Value;
return result;
}

2、获取标签中的属性： string str="<a href="www.csdn.net" class="main">CSDN</a>"  获取 “href” 的结果：www.csdn.net  

调用例子：string href=GetTitleContent(str,"a","href");

/// <summary>
/// 获取字符中指定标签的值
/// </summary>
/// <param name="str">字符串</param>
/// <param name="title">标签</param>
/// <param name="attrib">属性名</param>
/// <returns>属性</returns>
public static string GetTitleContent(string str, string title,string attrib)
{

string tmpStr = string.Format("<{0}[^>]*?{1}=(['""]?)(?<url>[^'""\s>]+)\1[^>]*>", title, attrib); //属性值

Match TitleMatch = Regex.Match(str, tmpStr, RegexOptions.IgnoreCase);

string result = TitleMatch.Groups["url"].Value;
return result;
}

注：以上方法为获取字符串中第一个结果的值。可以使用Foreach读取TitileMath中所有的匹配属性或值。

3。获取 <div class="brand_items"> 跟 </div> 之间的内容，<div class="brand_items"> 跟 </div> 可以重复出现

比如 ：

<div class="cont_left">
	<div class="cont_left_items"><a href="left.php?cid=QDE=" class="ma">数码手机</a></div>
	<div class="cont_left_items"><a href="left.php?cid=QTE=" class="ma">整机电教</a></div>
	<div class="cont_left_items"><a href="left.php?cid=QjE=" class="ma">办公耗材</a></div>
	<div class="cont_left_items2"><a href="left.php?cid=RDE=" class="ma2">硬件周边</a></div>
	<div class="cont_left_items"><a href="left.php?cid=RTE=" class="ma">网络通讯</a></div>
	<div class="cont_left_items"><a href="left.php?cid=RzE=" class="ma">安防监控</a></div>
	<div class="cont_left_items"><a href="left.php?cid=QDFAMQ==" class="ma">IT综合</a></div>
	</div>
	<div class="cont_right">
	<div class="cont_right_items2"><a href="prod_list.php?cid=RDE=&sid=SDE=" class="ma3" target="_parent">摄像头</a></div>
	<div class="rg_brand_list"> <div class="brand_items"><a href="prod_list.php?bid=QDFBMUYx&cid=RDE=&sid=SDE=" target="_parent" class="ma2">罗技</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=QDFCMUQx&cid=RDE=&sid=SDE=" target="_parent" class="ma2">新贵</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=QDFDMUYx&cid=RDE=&sid=SDE=" target="_parent" class="ma2">清华紫光</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=QDFDMUUx&cid=RDE=&sid=SDE=" target="_parent" class="ma2">达克浩思</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=QDFGMUYxPzFBMQ==&cid=RDE=&sid=SDE=" target="_parent" class="ma2">ASJ奥视嘉</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=RzE/MUUxRDFHMQ==&cid=RDE=&sid=SDE=" target="_parent" class="ma2">百视通</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=RzE/MUgxSDE/MQ==&cid=RDE=&sid=SDE=" target="_parent" class="ma2">创新</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=RzFAMT8xPzE/MQ==&cid=RDE=&sid=SDE=" target="_parent" class="ma2">海畅</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=RzFAMT8xQDFEMQ==&cid=RDE=&sid=SDE=" target="_parent" class="ma2">昂达</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=RzFAMT8xQjFAMQ==&cid=RDE=&sid=SDE=" target="_parent" class="ma2">网眼</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=RzFBMUMxPzFAMQ==&cid=RDE=&sid=SDE=" target="_parent" class="ma2">网缘</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=RzFDMUUxQjFGMQ==&cid=RDE=&sid=SDE=" target="_parent" class="ma2">黑石</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=QDFBMUgx&cid=RDE=&sid=SDE=" target="_parent" class="ma2">奥尼ANC</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=QDFCMUYx&cid=RDE=&sid=SDE=" target="_parent" class="ma2">鼎易</a></div>
	<div class="brand_items"><a href="prod_list.php?bid=RzFCMUcxQDE/MQ==&cid=RDE=&sid=SDE=" target="_parent" class="ma2">清华同方</a></div>
	</div> <div class="cont_right_items"><a href="prod_list.php?cid=RDE=&sid=QzFBMQ==" class="ma3" target="_parent">液晶显示器</a></div>
	<div class="cont_right_items"><a href="prod_list.php?cid=RDE=&sid=RDE/MQ==" class="ma3" target="_parent">主板</a></div>
	<div class="cont_right_items"><a href="prod_list.php?cid=RDE=&sid=RDFAMQ==" class="ma3" target="_parent">显卡</a></div>
	<div class="cont_right_items"><a href="prod_list.php?cid=RDE=&sid=RDFBMQ==" class="ma3" target="_parent">CPU</a></div>
	<div class="cont_right_items"><a href="prod_list.php?cid=RDE=&sid=RTFAMQ==" class="ma3" target="_parent">散热器</a></div>
	<div class="cont_right_items"><a href="prod_list.php?cid=RDE=&sid=RzFDMQ==" class="ma3" target="_parent">键盘</a></div>

Regex regex = new Regex("(?<=(<div class="brand_items">))[.\s\S]*?(?=(</div>))", RegexOptions.IgnoreCase);

for (Match match = regex.Match(content); match.Success; match = match.NextMatch())

{

    string d=match.Groups[0].ToString();//每个<div class="brand_items"> </div>里的内容

}

获取<div class="info_mid_left"> 跟 <div class="endarea"> 之间的内容，唯一性   <div class="info_mid_left"> 跟 <div class="endarea"> 不重复出现

Regex regex1 = new Regex("(?<=(<div class="info_mid_left">))[.\s\S]*?(?=(<div class="endarea">))", RegexOptions.IgnoreCase);

string Pcontent = regex1.Match(content).Groups[0].Value;

获取 <td class="paramFontS2" style="text-align:center; font-size:13px;">技嘉 H61M-DS2DVI </td>     td里的Text内容，td有多种不确定属性的时候

Regex regex2 = new Regex("<td[^>]*?>(?<Text>[^<]*)</td>", RegexOptions.IgnoreCase);

for (Match match2 = regex2.Match(d1); match2.Success; match2 = match2.NextMatch())

{

   name = match2.Groups["Text"].Value;

}

 获取input控件的value值 

public string FindValueByName(string str, string inputname)
{
//string reg = @"<input name=""(?<name>.*?)"" [sS]*?value=""(?<value>.*?)"" [sS]*?>";
string reg = "<input[^>]+name="*(?<name>[^\s">]+)"*[^>]*value="*(?<value>[^\s">]+)"*[^>]*>";
Regex r = new Regex(reg, RegexOptions.None);
Match match = r.Match(str);
string aa = "";
while (match.Success)
{
string name = match.Groups["name"].ToString();
string value = match.Groups["value"].ToString();
if (name == inputname)
{
return value;
}
else
{
match = match.NextMatch();
}
}
return aa;
}

清除所有a标签：string str1 = Regex.Replace(str, @"</?a[^>]*>", "");

清除所有script 包括script里面的代码      str1 = Regex.Replace(str, @"<script[^>]*>([sS](?!<script))*?</script>", "");