根据需要在C＃中的XPath不工作 [英] XPath doesn't work as desired in C#

问题描述

我的代码不会返回节点

XmlDocument xml = new XmlDocument();
xml.InnerXml = text;

XmlNode node_ =  xml.SelectSingleNode(node);
return node_.InnerText; // node_ = null !

我敢肯定我的XML和XPath是正确的。

I'm pretty sure my XML and Xpath are correct.

我的Xpath： / ItemLookupResponse / OperationRequest /请求ID

我的XML：

<?xml version="1.0"?>
<ItemLookupResponse xmlns="http://webservices.amazon.com/AWSECommerceService/2005-10-05">
  <OperationRequest>
    <RequestId>xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxxx</RequestId>
    <!-- the rest of the xml is irrelevant -->
  </OperationRequest>
</ItemLookupResponse>

节点我的XPath返回总是空的某些原因。 ？谁能帮

The node my XPath returns is always null for some reason. Can someone help?

推荐答案

您的XPath几乎是正确的 - 它只是没有考虑到根目录下的默认XML命名空间！节点

Your XPath is almost correct - it just doesn't take into account the default XML namespace on the root node!

<ItemLookupResponse 
    xmlns="http://webservices.amazon.com/AWSECommerceService/2005-10-05">
             *** you need to respect this namespace ***

您需要采取考虑并改变你这样的代码：

You need to take that into account and change your code like this:

XmlDocument xml = new XmlDocument();
xml.InnerXml = text;

XmlNamespaceManager nsmgr = new XmlNamespaceManager(xml.NameTable);
nsmgr.AddNamespace("x", "http://webservices.amazon.com/AWSECommerceService/2005-10-05");

XmlNode node_ = xml.SelectSingleNode(node, nsmgr);

和那么你的XPath应该是：

And then your XPath ought to be:

 /x:ItemLookupResponse/x:OperationRequest/x:RequestId

现在，您node_.InnerText绝对应该的不的是NULL了！

Now, your node_.InnerText should definitely not be NULL anymore!

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