VBA 循环遍历 XML 节点并在每个节点中获取值

Posted 2023-02-19

【中文标题】VBA 循环遍历 XML 节点并在每个节点中获取值

【英文标题】：VBA loop through XML nodes and get values within each node

【发布时间】：2021-06-22 15:12:58

【问题描述】：

在 Access 中，我有一个表单，它将加载用户提供的 XML 文件，然后循环从文件中提取信息。这是 XML 文件的结构。

<manifest identifier="MANIFEST1">
  <organizations />
  <resources>  
    <resource identifier="AMS_EDDC7208" type="imsqti_xmlv1p2p1" href="a1231.xml"> 
      <metadata> 
        <schema>abc123</schema>
        <schemaversion>1.2</schemaversion>
        <metadata> 
          <exmetadata>
            <exmetadataSection identifier="841" name="Topic">
              <description>
              </description>
              <exmetadataparameterSet>
                <param name="Topic" type="String">Math</param>
                <param name="Gender" type="String">N</param>
                <param name="Race" type="String">Z</param>
                <param name="Difficulty Level" type="String">HARD</param>
              </exmetadataparameterSet>
              <exdependencysection identifierref="" /> 
            </exmetadataSection>
            <exmetadataSection identifier="842" name="Math Reasoning">
              <description>
              </description>
              <exmetadataparameterSet>
                <param name="Item_Type" type="String">A</param>
                <param name="Cont1" type="String">ARI</param>
                <param name="Cont2" type="String">REM</param>
                <param name="Cognitive" type="String">PUR</param>
              </exmetadataparameterSet>
              <exdependencysection identifierref="" />
            </exmetadataSection>
          </exmetadata>
        </metadata>
      </metadata>
      <file href="a1231.xml" />
    </resource>
  <resources>  
    <resource identifier="AMS_AB3dC7208" type="imsqti_xmlv1p2p1" href="a1232.xml"> 
      <metadata> 
        <schema>abc123</schema>
        <schemaversion>1.2</schemaversion>
        <metadata> 
          <exmetadata>
            <exmetadataSection identifier="841" name="Topic">
              <description>
              </description>
              <exmetadataparameterSet>
                <param name="Topic" type="String">Math</param>
                <param name="Gender" type="String">N</param>
                <param name="Race" type="String">Z</param>
                <param name="Difficulty Level" type="String">HARD</param>
              </exmetadataparameterSet>
              <exdependencysection identifierref="" /> 
            </exmetadataSection>
            <exmetadataSection identifier="842" name="Math Reasoning">
              <description>
              </description>
              <exmetadataparameterSet>
                <param name="Item_Type" type="String">A</param>
                <param name="Cont1" type="String">GEO</param>
                <param name="Cont2" type="String">ABS</param>
                <param name="Cognitive" type="String">PUR</param>
              </exmetadataparameterSet>
              <exdependencysection identifierref="" />
            </exmetadataSection>
          </exmetadata>
        </metadata>
      </metadata>
      <file href="a1232.xml" />
    </resource>  
  <resources>  
    <resource identifier="AMS_EE0023DC7208" type="imsqti_xmlv1p2p1" href="a1233.xml"> 
      <metadata> 
        <schema>abc123</schema>
        <schemaversion>1.2</schemaversion>
      </metadata>
      <file href="a1233.xml" />
    </resource>  
  <resources>  
    <resource identifier="AMS_XXZDF2323CC208" type="imsqti_xmlv1p2p1" href="a1234.xml"> 
      <metadata> 
        <schema>abc123</schema>
        <schemaversion>1.2</schemaversion>
        <metadata> 
          <exmetadata>
            <exmetadataSection identifier="841" name="Topic">
              <description>
              </description>
              <exmetadataparameterSet>
                <param name="Topic" type="String">Math</param>
                <param name="Gender" type="String">N</param>
                <param name="Race" type="String">Z</param>
                <param name="Difficulty Level" type="String">HARD</param>
              </exmetadataparameterSet>
              <exdependencysection identifierref="" /> 
            </exmetadataSection>
            <exmetadataSection identifier="842" name="Math Reasoning">
              <description>
              </description>
              <exmetadataparameterSet>
                <param name="Item_Type" type="String">A</param>
                <param name="Cont1" type="String">ALG</param>
                <param name="Cont2" type="String">APP</param>
                <param name="Cognitive" type="String">REA</param>
              </exmetadataparameterSet>
              <exdependencysection identifierref="" />
            </exmetadataSection>
          </exmetadata>
        </metadata>
      </metadata>
      <file href="a1234.xml" />
    </resource>          
</manifest>

我能够遍历 resource 节点并获取每个节点的 identifer 和 href 文本，但我遇到了问题当我遍历每个资源节点时，从 param 节点获取正确的详细信息。我只需要某些参数值，因此尝试使用 SelectSingleNode 但意识到这只会给我它遇到的第一个集合。

Dim XDoc, nodesThatMatter  As Object
Dim strFieldName, strESID, strFile, strTopic, strItemType, strCont1, strCont2, strCognitive As String
Set XDoc = CreateObject("MSXML2.DOMDocument")
XDoc.async = False: XDoc.validateOnParse = False
XDoc.Load (Me.FileIn)

Set nodesThatMatter = XDoc.SelectNodes("//resource")
   
For Each node In nodesThatMatter
    
    'resource identifier
    strESID = node.Attributes.Item(0).Text
    'resource file
    strFile = node.Attributes.Item(2).Text
            
    strTopic = node.SelectSingleNode("//param[@name='Topic']").Text
    strItemType = node.SelectSingleNode("//param[@name='Item_Type']").Text
    strCont1 = node.SelectSingleNode("//param[@name='Cont1']").Text
    strCont2 = node.SelectSingleNode("//param[@name='Cont2']").Text
    strCognitive = node.SelectSingleNode("//param[@name='Cognitive']").Text
              
         
Next node
 
Set XDoc = Nothing

如何根据我所在的资源节点更新这些值，并考虑节点何时可能没有参数节点？

【参考方案1】：

我最终深入到子节点并能够得到我需要的东西。仍然想知道是否有更直接的方法可以通过名称直接进入特定级别？