xml - 为什么XPath表达式无法通过.SelectSingleNode()找到我想要的节点？

Question

这是我用来在Sharepoint列表项的DOM文档中查找某个节点的内部文本的代码：

'parse XML of a list item to get the field value
Private Function getFieldValueFromXml(xml As Variant, fieldName As Variant) As Variant

Dim node As IXMLDOMNode
Dim namespaceAndName As String

'set namespace string for XPath search, using field name
namespaceAndName = "/d:" & fieldName

Set domDoc = New DOMDocument60

'load DOM document with XML
domDoc.LoadXML xml

'set selection namespace for XPath search
domDoc.SetProperty "SelectionNamespaces", "xmlns:d='http://schemas.microsoft.com/ado/2007/08/dataservices'"

'get first node with this namespace (a list item should have only one node with a given field name)
Set node = domDoc.SelectSingleNode(namespaceAndName)

getFieldValueFromXml = node.text

End Function

当我通过ID号检索列表项时，这种方法很好用，但是当我使用$filter来获得它时，如下所示：

https://sps.utility.xyz.com/Sites/ABC/_api/web/lists/GetByTitle('Stations')/items?$filter=Title eq '020'

然后，当我尝试通过调用getFieldValueFromXml(result,"Id")查找值时，找不到节点。这是上述REST调用返回的XML：

<?xml version="1.0"?>
<feed xml:base="https://sps.utility.abc.com/Sites/asdaC/_api/" xmlns="http://www.w3.org/2005/Atom" xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" xmlns:georss="http://www.georss.org/georss" xmlns:gml="http://www.opengis.net/gml">
<id>5a608d14-721b-4076-9ed0-91eccd9b70ec</id>
<title/>
<updated>2017-10-04T22:24:47Z</updated>
<entry m:etag="&quot;42&quot;">
<id>Web/Lists(guid'f9565c6c-334c-4953-a117-5dd9b0cd38a5')/Items(415)</id>
<category term="SP.Data.StationsListItem" scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme"/>
<title/>
<updated>2017-10-04T22:24:47Z</updated>
<author>
<name/>
</author>
<content type="application/xml">
<m:properties>
<d:FileSystemObjectType m:type="Edm.Int32">0</d:FileSystemObjectType>
<d:Id m:type="Edm.Int32">415</d:Id>
<d:ReferenceImages m:type="SP.FieldUrlValue">
<d:Description>some number 131553</d:Description>
<d:Url>http://google.com</d:Url>
</d:ReferenceImages>
<d:CDScope m:type="Edm.Boolean">true</d:CDScope>
<d:ID m:typ
e="Edm.Int32">415</d:ID>
<d:Modified m:type="Edm.DateTime">2017-10-04T20:15:54Z</d:Modified>
<d:Created m:type="Edm.DateTime">2016-03-27T19:21:49Z</d:Created>
<d:AuthorId m:type="Edm.Int32">50</d:AuthorId>
<d:EditorId m:type="Edm.Int32">330</d:EditorId>
<d:OData__UIVersionString>18.0</d:OData__UIVersionString>
<d:Attachments m:type="Edm.Boolean">false</d:Attachments>
<d:GUID m:type="Edm.Guid">f31fcf07-0d81-442e-8621-56d09a8507f6</d:GUID>
</m:properties>
</content>
</entry>
</feed>

在getFieldValueFromXml()中，.SelectSingleNode(namespaceAndName) call returns Nothing. How should I modify my code to pick up the Id`的值是多少？

Answer 1

看来您只是在搜寻根目录。

尝试使用类似以下内容搜索后裔：

.SelectSingleNode(".//d:Id")