XML 规范化在转换后的输出中返回空元素

Question

我有一篇相关帖子询问如何选择节点使用 XPath 语句从 XmlDocument 中获取。

让 SelectNodes 工作的唯一方法是创建一个非默认命名空间“x”，然后在 XPath 语句中显式引用节点。

虽然这有效并为我提供了一个节点列表，但规范化无法在输出中为我选择的节点生成任何内容。

我尝试使用 XmlDsigExcC14NTransform 并指定命名空间，但这会产生相同的输出。

下面是生成的 xml 输出的示例（使用我的 相关帖子）：

<Applications xmlns="http://www.myApps.co.uk/">
  <Application>
    <ApplicantDetails>
      <Title>
      </Title>
      <Forename>
      </Forename>
      <Middlenames>
        <Middlename>
        </Middlename>
      </Middlenames>
      <PresentSurname>
      </PresentSurname>
      <CurrentAddress>
        <Address>
          <AddressLine1>
          </AddressLine1>
          <AddressLine2>
          </AddressLine2>
          <AddressTown>
          </AddressTown>
          <AddressCounty>
          </AddressCounty>
          <Postcode>
          </Postcode>
          <CountryCode>
          </CountryCode>
        </Address>
        <ResidentFromGyearMonth>
        </ResidentFromGyearMonth>
      </CurrentAddress>
    </ApplicantDetails>
  </Application>
  <Application>
    <ApplicantDetails>
      <Title>
      </Title>
      <Forename>
      </Forename>
      <Middlenames>
        <Middlename>
        </Middlename>
      </Middlenames>
      <PresentSurname>
      </PresentSurname>
      <CurrentAddress>
        <Address>
          <AddressLine1>
          </AddressLine1>
          <AddressLine2>
          </AddressLine2>
          <AddressTown>
          </AddressTown>
          <AddressCounty>
          </AddressCounty>
          <Postcode>
          </Postcode>
          <CountryCode>
          </CountryCode>
        </Address>
        <ResidentFromGyearMonth>
        </ResidentFromGyearMonth>
      </CurrentAddress>
    </ApplicantDetails>
  </Application>
</Applications>

Answer 1

的问题

另一位 StackOverflow 用户也遇到了类似 代码中，我发现结果会有所不同，具体取决于将节点传递到 LoadInput 方法中的方式。实现下面的代码是有效的。

我仍然很好奇为什么它会以一种方式而不是另一种方式工作，但会留到未雨绸缪

static void Main(string[] args)
{
    string path = @"..\..\TestFiles\Test_1.xml";
    if (File.Exists(path) == true)
    {
        XmlDocument xDoc = new XmlDocument();
        xDoc.PreserveWhitespace = true;
        using (FileStream fs = new FileStream(path, FileMode.Open))
        {
            xDoc.Load(fs);
        }

        //Instantiate an XmlNamespaceManager object. 
        System.Xml.XmlNamespaceManager xmlnsManager = new System.Xml.XmlNamespaceManager(xDoc.NameTable);

        //Add the namespaces used to the XmlNamespaceManager.
        xmlnsManager.AddNamespace("x", "http://www.myApps.co.uk/");

        // Create a list of nodes to have the Canonical treatment
        XmlNodeList nodeList = xDoc.SelectNodes("/x:ApplicationsBatch/x:Applications|/x:ApplicationsBatch/x:Applications//*", xmlnsManager);

        //Initialise the stream to read the node list
        MemoryStream nodeStream = new MemoryStream();
        XmlWriter xw = XmlWriter.Create(nodeStream);
        nodeList[0].WriteTo(xw);
        xw.Flush();
        nodeStream.Position = 0;

        // Perform the C14N transform on the nodes in the stream
        XmlDsigC14NTransform transform = new XmlDsigC14NTransform();
        transform.LoadInput(nodeStream);

        // use a new memory stream for output of the transformed xml 
        // this could be done numerous ways if you don't wish to use a memory stream
        MemoryStream outputStream = (MemoryStream)transform.GetOutput(typeof(Stream));
        File.WriteAllBytes(@"..\..\TestFiles\CleanTest_1.xml", outputStream.ToArray());
    }
}