使用vb6中的xpath在youtube提要响应中选择节点

Question

对于这个xml中的每个条目，我需要获得"标题"和第一个缩略图。这是媒体中的第一个图像：组

<?xml version='1.0' encoding='UTF-8'?>
<feed xmlns='http://www.w3.org/2005/Atom' xmlns:media='http://search.yahoo.com/mrss/'>
<entry>
<title>Progression! 9 more pounds to goo!</title>
<media:group>
<media:thumbnail url='http://i.ytimg.com/vi/7MTjYXt3rLQ/default.jpg'/>
<media:thumbnail url='http://i.ytimg.com/vi/7MTjYXt3rLQ/mqdefault.jpg'/>
<media:thumbnail url='http://i.ytimg.com/vi/7MTjYXt3rLQ/hqdefault.jpg'/>
<media:thumbnail url='http://i.ytimg.com/vi/7MTjYXt3rLQ/1.jpg'/>
<media:thumbnail url='http://i.ytimg.com/vi/7MTjYXt3rLQ/2.jpg'/>
<media:thumbnail url='http://i.ytimg.com/vi/7MTjYXt3rLQ/3.jpg'/>
</media:group>
</entry>
<entry>
<title>Plank Variations Workout with Max Wettstein</title>
<media:group>
<media:thumbnail url='http://i.ytimg.com/vi/O1Nd8lZFGpc/default.jpg'/>
<media:thumbnail url='http://i.ytimg.com/vi/O1Nd8lZFGpc/mqdefault.jpg'/>
<media:thumbnail url='http://i.ytimg.com/vi/O1Nd8lZFGpc/hqdefault.jpg'/>
<media:thumbnail url='http://i.ytimg.com/vi/O1Nd8lZFGpc/1.jpg'/>
<media:thumbnail url='http://i.ytimg.com/vi/O1Nd8lZFGpc/2.jpg'/>
<media:thumbnail url='http://i.ytimg.com/vi/O1Nd8lZFGpc/3.jpg'/>
</media:group>
</entry>
</feed>

这是我的代码

 Dim xmlDoc As MSXML2.DOMDocument30
    Dim xmlEntryNode As MSXML2.IXMLDOMNode
    Dim xmlEntryNodes As IXMLDOMNodeList
    Dim xmlC1Nodes As IXMLDOMNodeList
    Dim ns As String
    Set xmlDoc = New DOMDocument30
    ns = txtNS.Text
    xmlDoc.setProperty "SelectionLanguage", "XPath"
    xmlDoc.setProperty "SelectionNamespaces", ns
    If xmlDoc.loadXML(txtXml.Text) = False Then
        appendText "xml document load failed"
        Exit Sub
    End If
    Set xmlEntryNodes = xmlDoc.documentElement.selectNodes(/x:feed/x:entry)
    Dim i As Integer
    For i = 0 To xmlEntryNodes.length - 1
        Set xmlEntryNode = xmlEntryNodes(i)
        appendText xmlEntryNode.Text
        Set xmlC1Nodes = xmlDoc.selectNodes(//media:group/media:thumbnail[1]/@url)
        If xmlC1Nodes.length > 0 Then
            Dim j As Integer
            For j = 0 To xmlC1Nodes.length - 1
                appendText xmlC1Nodes(j).Text
            Next
        End If
    Next
    Exit Sub

这是我的输出

Progression! 9 more pounds to goo!  
http://i.ytimg.com/vi/7MTjYXt3rLQ/default.jpg   
http://i.ytimg.com/vi/O1Nd8lZFGpc/default.jpg    Plank Variations
Workout with Max Wettstein  
http://i.ytimg.com/vi/7MTjYXt3rLQ/default.jpg   
http://i.ytimg.com/vi/O1Nd8lZFGpc/default.jpg

有人能帮我调整一下吗，让它每个条目只返回一个图像

Answer 1

我并不精通VB6，但从XPath的角度来看，我会选择相对于您已经拥有的xmlEntryNode：

Set xmlC1Nodes = xmlEntryNode.selectNodes("media:group/media:thumbnail[1]/@url")

（我不明白为什么你的XPath表达式没有引号……但你说它会产生输出……）

或者，如果selectNodes（）方法仅适用于XML文档，则

Set xmlC1Nodes = xmlDoc.selectNodes(
        "/*/x:entry[" + i + "]/media:group/media:thumbnail[1]/@url")

Answer 2

有人能帮我调整一下吗，让它每个条目只返回一个图像

使用类似的东西（多年来一直没有使用MSXML或VB）：

Set urlAttrib = xmlEntryNode.SelectSingleNode("media:group/media:thumbnail[1]/@url")
wantedText = urlAttrib.nodeValue