C# Can'；t使用HTML agility pack从HTML代码中获取a值

我想从HTML代码中获取一个值，我正在使用这个C#代码使用HtmlAgilityPack从这个HTML代码中获取值

我只想要地址和电话号码

<div class="company-info">
    <div id="o-company" class="edit-overlay-section" style="padding-top:5px; width: 400px;">
        <a href="http://www.manta.com/c/mm23df2/us-cellular" class="company-name">
            <h1 class="profile-company_name" itemprop="name">US Cellular</h1>
        </a>
    </div>      
    <div class="addr addr-co-header-gamma" itemprop="address"itemscope=""itemtype="http://schema.org/PostalAddress">
        <em>United States Cellular Corporation</em>
        <div class="company-address">   
        <div itemprop="streetAddress">2401 12th Avenue NW # 104B</div>
            <span class="addressLocality" itemprop="addressLocality">Ardmore</span>,
            <span class="addressRegion" itemprop="addressRegion">OK</span>      
            <span class="addresspostalCode" itemprop="postalCode">73401-1471</span>
        </div>
        <dl class="phone_info"><dt>Phone:</dt>
        <dd class="tel" itemprop="telephone">(580) 490-3333</dd>
...

---

有人能帮我吗？谢谢。

您需要提供有关所获得异常的更多信息（例如在哪一行引发异常），但是

如果未找到与XPath表达式匹配的项，则

SelectNodes

方法将返回

null

，这意味着您必须在遍历节点之前检查返回值是否为

null

。比如：

var companyAddressNodes = hDoc.DocumentNode.SelectNodes("//div[@itemprop='company-address']");

if (companyAddressNodes == null) {
    //Throw properly exception here, log the error, or do anything you want...
    throw new Exception("No company address node found. Perhaps the page layout changed?");
}

foreach (HtmlNode hNode in )
{
    Response.Write(hNode.InnerText.ToString());
}

---

你能提供完整的stacktrace吗？我试过了，但找不到任何解决方案，这就是为什么贴在这里也许这有帮助：可能的重复

"Object reference not set to an instance of an object"

var companyAddressNodes = hDoc.DocumentNode.SelectNodes("//div[@itemprop='company-address']");

if (companyAddressNodes == null) {
    //Throw properly exception here, log the error, or do anything you want...
    throw new Exception("No company address node found. Perhaps the page layout changed?");
}

foreach (HtmlNode hNode in )
{
    Response.Write(hNode.InnerText.ToString());
}