Question

我正在尝试用简单的XML获取节点，但无论我尝试什么，我总是得到null。

我猜这个问题是命名空间。

我只是想获取ID元素的值331377697.

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load("E:\\0323.xml");

XmlNamespaceManager manager = new XmlNamespaceManager(xmlDoc.NameTable);
manager.AddNamespace("cac", "http://xxxxxx Some URL XXXX");
manager.AddNamespace("cbc", "http://xxxxxx Some URL XXXX");

string query = "/StandardBusinessDocument/Invoice/cbc:ID";

XmlNode xmlNode = xmlDoc.SelectSingleNode(query, manager);

XML：

<StandardBusinessDocument xmlns="http://www.unece.org/cefact/namespaces/StandardBusinessDocumentHeader">
      <StandardBusinessDocumentHeader>
      ...
      </StandardBusinessDocumentHeader>
<Invoice xmlns="urn:oasis:names:specification:ubl:schema:xsd:Invoice-2" xmlns:cac="urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2" xmlns:cbc="urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2" xmlns:ccts="urn:un:unece:uncefact:documentation:2"
...
</Invoice>
    <cbc:UBLVersionID>2.1</cbc:UBLVersionID>
    <cbc:CustomizationID>1234</cbc:CustomizationID>
    <cbc:ProfileID>1234564</cbc:ProfileID>
    <cbc:ID>331377697</cbc:ID>
    <cbc:IssueDate>2017-03-23</cbc:IssueDate>
    <cbc:InvoiceTypeCode listID="UNCL1001">380</cbc:InvoiceTypeCode>
    <cbc:DocumentCurrencyCode listID="ISO4217">NOK</cbc:DocumentCurrencyCode>
    <cac:OrderReference>
        <cbc:ID>146136</cbc:ID>
    </cac:OrderReference>

    ...

Answer 1

您必须指定确切的名称空间。

此外，您还必须为XPath中的所有元素指定名称空间前缀。

manager.AddNamespace("nsDoc", "http://www.unece.org/cefact/namespaces/StandardBusinessDocumentHeader");
manager.AddNamespace("nsInvoice", "urn:oasis:names:specification:ubl:schema:xsd:Invoice-2");
manager.AddNamespace("cbc", "urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2");

string query = "/nsDoc:StandardBusinessDocument/nsInvoice:Invoice/cbc:ID";

它应该有用。

使用XPath获取XML节点将返回null

1 个答案: