LINQ to XML 导航文件答案

【问题标题】：LINQ to XML NAVIGATING FILELINQ to XML 导航文件
【发布时间】：2014-08-21 15:35:25
【问题描述】：

我是 LinQ to XML 的新手，我在使用 Xdocument（在这种情况下）从 XML 文件中提取特定值并开始至少将其返回到控制台时遇到了麻烦。

在 XLM 中，我只需要显示某些值； 4GB493594008000-JENEXP18082014A、A1、20（在statisticalValue元素中）等

任何指针将不胜感激 - 谢谢。

有问题的 XML 是

  <?xml version="1.0" encoding="utf-8"?>
<declarationGbResponse xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="demo.com/test/DeclarationGbResponse">
  <declarationIdentity>
    <declarationUcr xmlns="demo.org.uk/DeclarationGbIdentityType">4GB493594008000-JENEXP18082014A</declarationUcr>
  </declarationIdentity>
  <responseType>ACC</responseType>
  <responseTime>2014-08-18T13:36:32.79</responseTime>
  <isFirstAcceptanceResponse>true</isFirstAcceptanceResponse>
  <externalReferences/>
  <!-- element -->
  <acceptanceResponse>
  <!-- element -->
    <ICS xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">A1</ICS>
    <entryRoute xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">H</entryRoute>
    <statusOfExportEntry xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">1</statusOfExportEntry>
    <entryTime xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">2014-08-18T13:36:00</entryTime>
    <entryEpuNumber xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">120</entryEpuNumber>
    <entryNumber xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">A05605F</entryNumber>
    <entryVersionNumber xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">1</entryVersionNumber>
    <movementReferenceNumber xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">14GB08X33073603018</movementReferenceNumber>
    <declarationExchangeRate xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">1</declarationExchangeRate>
    <declarationCurrency xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">
      <currencyCode xmlns="demo.org.uk/test/Currency">GBP</currencyCode>
    </declarationCurrency>
    <customsValueForDuty xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">
      <value xmlns="demo.org.uk/test/MonetaryType">20</value>
    </customsValueForDuty>
    <customsDutyPayable xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">
      <value xmlns="demo.org.uk/test/MonetaryType">0</value>
    </customsDutyPayable>
    <deferedRevenue xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">
      <value xmlns="demo.org.uk/test/MonetaryType">0</value>
    </deferedRevenue>
    <immediateRevenue xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">
      <value xmlns="demo.org.uk/test/MonetaryType">0</value>
    </immediateRevenue>
    <revenuePayable xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">
      <value xmlns="demo.org.uk/test/MonetaryType">0</value>
    </revenuePayable>
    <itemResponses xmlns="demo.org.uk/test/DeclarationGbAcceptanceResponse">
      <itemResponse>
        <itemNumber xmlns="demo.org.uk/test/DeclarationGbItemResponse">1</itemNumber>
        <statisticalValue xmlns="demo.org.uk/test/DeclarationGbItemResponse">
          <value xmlns="demo.org.uk/test/MonetaryType">20</value>
        </statisticalValue>
      </itemResponse>
    </itemResponses>
  </acceptanceResponse>
</declarationGbResponse

【问题讨论】：

标签： c# linq-to-xml

【解决方案1】：

您的 XML 在不同级别声明了不同的默认命名空间，您需要非常小心才能看到哪个元素在哪个命名空间中。

如果您不知道，默认命名空间是派生给后代元素的。意味着，声明默认命名空间的元素及其所有没有前缀和没有不同默认命名空间声明的后代被认为在同一个命名空间中，即祖先的命名空间。例如，由于没有前缀或不同的默认命名空间声明，<acceptanceResponse> 元素被考虑在其父命名空间中，即“demo.com/test/DeclarationGbResponse”。

要选择命名空间中的元素，可以使用“XNamespace+元素的本地名称”：

XDocument doc = /* load your XML to XDocument */
XNamespace gbResponse = "demo.com/test/DeclarationGbResponse";
XNamespace gbIdentityType = "demo.org.uk/DeclarationGbIdentityType";
XNamespace gbAcceptanceRespons = "demo.org.uk/test/DeclarationGbAcceptanceResponse";
XNamespace gbItemResponse = "demo.org.uk/test/DeclarationGbItemResponse";
XNamespace monetaryType = "demo.org.uk/test/MonetaryType";
var declarationUcr = (string)doc.Root
                                .Element(gbResponse + "declarationIdentity")
                                .Element(gbIdentityType + "declarationUcr");
var ICS = (string)doc.Root
                     .Element(gbResponse + "acceptanceResponse")
                     .Element(gbAcceptanceRespons + "ICS");
var value = (string)doc.Root
                       .Element(gbResponse + "acceptanceResponse")
                       .Element(gbAcceptanceRespons + "itemResponses")
                       .Element(gbAcceptanceRespons + "itemResponse")
                       .Element(gbItemResponse + "statisticalValue")
                       .Element(monetaryType + "value");
Console.WriteLine(declarationUcr);
Console.WriteLine(ICS);
Console.WriteLine(value);

【讨论】：