C#不能查询XML但可以遍历节点？

Question

与有关。

我正在尝试从 XML 文件中读取节点看起来像这样：

<?xml version="1.0" encoding="UTF-8" ?>
<AuthorIT>
    <Objects>
        <Media>don't care</Media>
        <Style>don't care</Style>
        <Book>don't care</Book>
        <Topic>don't care</Topic>
        <Topic>
            <Object>
                <Description>Performance Evidence</Description>
            </Object>
            <Text>This is what I want to select</Text>
        </Topic>
    </Objects>
</AuthorIT>

但是查询不到。我已将 XmlDocument、XPath 和 Linq 尝试到 XML.

我已在 http://XPather.com 上验证我的 XPath 是正确的。


            /* this doesn't work but the XPath has been verified */
            XPathNavigator nav;
            XPathDocument docNav;
            string xPath;

            docNav = new XPathDocument(localFile);
            nav = docNav.CreateNavigator();
            xPath = "//Topic[Object/Description = 'Performance Evidence']/Text";
            string value = nav.SelectSingleNode(xPath).Value;

我可以使用 XmlDocument 遍历 XML 个节点，但我不想用一系列嵌套的 foreach 循环来代替单个查询。

 XmlDocument doc = new XmlDocument();
 doc.Load(localFile);
 XmlNodeList xmlNodes = doc.SelectNodes("/");

 /* direct query doesn't work, but traversing the nodes does? */
 foreach (XmlNode node in xmlNodes)
 {
     if (node.Name == "#document")
     {
         foreach (XmlNode subNode in node.ChildNodes)
         {
             if (subNode.Name == "AuthorIT")
             {
                 foreach (XmlNode subSubNode in subNode.ChildNodes)
                 {
                     if (subSubNode.Name == "Objects")
                     {
                         foreach (XmlNode subSubSubNode in subSubNode.ChildNodes)
                         {
                             if (subSubSubNode.Name == "Topic")
                             {
// I didn't finish writing this, because it's a ridiculous way to do it... but it works
                             }
                         }
                     }
                 }
             }
         }
     }
 }

我做错了什么吗？

一些属性的XML文件会导致这种情况？（如果是这样，我该如何解决？）

Answer 1

如果您只需要存储在 <Text> 属性中的值，则无需遍历所有内容，请尝试以下操作：

var doc = XDocument.Parse(File.ReadAllText(filePath));
var value = doc.XPathSelectElement("/AuthorIT/Objects/Topic/Text").Value;

Answer 2

示例中遗漏的内容 XML 是解决方案的关键...命名空间！

我找到了另一个问题的答案：Using Xpath With Default Namespace in C#

C#不能查询XML但可以遍历节点？

C# can't query XML but can traverse the nodes?

c#

xml

xpath

linq-to-xml

xmldocument