无法获取包含特定文本的特定类型的子节点。

Question

使用下面的代码，我可以接收我的Xml中的所有<job>元素。但是，当我试图搜索具有一个名为<Name>的子任务且其文本等于"receiverjob"的作业时，即使作业存在，SelectNodes()方法仍然返回零。

XmlDocument dom = new XmlDocument();
dom.Load(textBoxFilePath.Text);
XmlNamespaceManager nsManager = new XmlNamespaceManager(dom.NameTable);
nsManager.AddNamespace("d", "http://quartznet.sourceforge.net/JobSchedulingData");
XmlNodeList jobElements = dom.DocumentElement.SelectNodes("descendant::d:job[name=receiverjob]", nsManager);

Xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- This file contains job definitions in schema version 2.0 format -->
<job-scheduling-data version="2.0" xmlns="http://quartznet.sourceforge.net/JobSchedulingData" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <processing-directives>
    <overwrite-existing-data>true</overwrite-existing-data>
  </processing-directives>
  <schedule>
    <job>
      <name>receiverjob</name>
      <group>receivergroup</group>
      <job-type>Quartz.Server.ArgumentReceiverJob, Quartz.Server</job-type>
      <job-data-map>
        <entry>
          <key>receivedargument</key>
          <value>hamburger</value>
        </entry>
      </job-data-map>
    </job>
    <trigger>
      <simple>
        <name>argumentreceiverJobTrigger</name>
        <group>argumentreceiverGroup</group>
        <description>Simple trigger to simply fire sample job</description>
        <job-name>receiverjob</job-name>
        <job-group>receivergroup</job-group>
        <misfire-instruction>SmartPolicy</misfire-instruction>
        <repeat-count>-1</repeat-count>
        <repeat-interval>10000</repeat-interval>
      </simple>
    </trigger>
    <job>
      <name>batchjob</name>
      <group>batchGroup</group>
      <job-type>Quartz.Server.BatchJob, Quartz.Server</job-type>
      <durable>true</durable>
      <recover>false</recover>
    </job>
    <trigger>
      <cron>
        <name>Trigger2</name>
        <group>DEFAULT</group>
        <job-name>batchjob</job-name>
        <job-group>batchGroup</job-group>
        <cron-expression>0/15 * * * * ?</cron-expression>
      </cron>
    </trigger>
    <job>
      <name>jobnamexxx</name>
    </job>
    <job>
      <name>jobnamexxx</name>
    </job>
    <job>
      <name>jobnamexxx</name>
    </job>
  </schedule>
</job-scheduling-data>

Answer 1

我不是XPath专家，但我怀疑您的查询现在试图找到name元素等于receiverjob元素的作业。我怀疑你想要这样的东西：

"descendant::d:job[name/text()='receiverjob']"

还可能需要将name元素限定在正确的命名空间中：

"descendant::d:job[d:name/text()='receiverjob']"

但是，我会强烈考虑使用LINQ，而不是使用非常简单的LINQ (IMO)：

XDocument doc = XDocument.Load(textBoxFilePath.Text);
XNamespace ns = "http://quartznet.sourceforge.net/JobSchedulingData";
var jobs = doc.Descendants(ns + "job")
              .Where(x => (string) x.Element(ns + "name") == "receiverjob");

我不确定XPath语法，但我对LINQ版本很有信心--这本身就是该解决方案好处的标志，IMO。(当然，对于没有使用LINQ的XPath专家来说，情况可能正好相反。)

Answer 2

您还需要在name元素上应用前缀，并且需要引用字符串文字："descendant::d:job[d:name = 'receiverjob']"。