vb.net - 更改嵌套XML中的属性

我有一个带有嵌套元素/节点的XML文件。我需要<proceduralStep>为每个节点及其子节点增加属性“ id”。我的第一个问题是我无法使用来更改属性 node.Attributes("id").Value = node.Attributes("id").Value + 1。它在上给出了错误node.Attributes("id").Value +1。这是父元素/proceduralStep/。第二个问题是，如果它是的子元素，则需要更改每个节点属性<proceduralStep>。因此，如果/proceduralStep/proceduralStep属性ID更改为1.1。我一直在网上搜索有关如何执行此操作的示例和说明，但没有找到任何可行的方法。

样本XML

<dmodule>
  <mainProcedure>
    <proceduralStep id="step1">
      <para>Step 1</para>
    </proceduralStep>
    <proceduralStep id="step2">
      <figure id="fig2">
        <title>xxxxx</title>
        <graphic infoEntityIdent="ICN-GAASI"></graphic>
      </figure>
    </proceduralStep>
    <proceduralStep id="step3">
      <para>Step 3 with link to step 2 (ID 23) here:
                <internalRef internalRefId="step2" internalRefTargetType="step"></internalRef></para>
      <figure id="fig3">
        <title>xxxxx</title>
        <graphic infoEntityIdent="ICN-GAASIB0"></graphic>
      </figure>
      <proceduralStep id="step3.1">
        <para>Step 3.2 with link to step 3.1 (ID 23a) here:
                    <internalRef internalRefId="step3.1" internalRefTargetType="step"></internalRef></para>
      </proceduralStep>
      <proceduralStep id="step3.2">
        <figure>
          <title>xxxxx</title>
          <graphic infoEntityIdent="ICN-GAASIB0-00-"></graphic>
        </figure>
        <proceduralStep id="step3.2.1">
          <figure>Step 3.3.1</figure>
        </proceduralStep>
        <proceduralStep id="step3.2.2">
          <para>Step 3.3.2 with link to step 3.3.1 (ID 23c1) here:
                        <internalRef internalRefId="step3.2.1" internalRefTargetType="step"></internalRef></para>
        </proceduralStep>
        <proceduralStep id="step3.2.3">
          <figure>Step 3.3.3</figure>
        </proceduralStep>
      </proceduralStep>
    </proceduralStep>
  </mainProcedure>
</dmodule>

无效的代码

        Dim doc As XDocument = XDocument.Load(FILENAME)
        Dim directoryName As String = Path.GetDirectoryName(FILENAME)
        Dim root As XElement = doc.Root
        Dim prefixStep As String = "step"
        Dim prefixFig As String = "fig"
        Dim nameResult As String = Path.GetFileName(FILENAME)
        Dim ns As XNamespace = root.GetDefaultNamespace()
        Dim mainProcedure As XElement = root.Descendants("mainProcedure").FirstOrDefault()

        RenumberStep(mainProcedure, prefixStep, ns)
        RenumberFigures(mainProcedure, prefixFig, ns)

        For Each internalRef As XElement In doc.Descendants(ns + "internalRef")
        Dim oldId As String = CType(internalRef.Attribute("internalRefId"), String)
            If Not oldId Is Nothing Then
                If dictionary.ContainsKey(oldId) Then
                    internalRef.SetAttributeValue("internalRefId", dictionary(oldId))
                Else
                    '  internalRef.SetAttributeValue("internalRefId", "Error : " & oldId)
                End If
            End If
        Next internalRef

        doc.Save(FILENAME)
Module Module1
    Public dictionary As New Dictionary(Of String, String)
    Public dictionaryFig As New Dictionary(Of String, String)

    Sub RenumberStep(parent As XElement, prefix As String, ns As XNamespace)
        Dim index As Integer = 1
        For Each proceduralStep As XElement In parent.Elements(ns + "proceduralStep")
            Dim oldId = CType(proceduralStep.Attribute("id"), String)
            If Not oldId Is Nothing Then
                dictionary.Add(oldId, prefix + index.ToString())
                proceduralStep.SetAttributeValue("id", prefix + index.ToString())
                RenumberStep(proceduralStep, prefix + index.ToString() + ".", ns)
            Else
                proceduralStep.SetAttributeValue("id", prefix + index.ToString())
            End If
            index = index + 1
        Next proceduralStep
    End Sub

    Sub RenumberFigures(parent As XElement, prefix As String, ns As XNamespace)
        Dim index As Integer = 1

        For Each figure As XElement In parent.Elements(ns + "figure")
            Dim oldfigId = CType(figure.Attribute("id"), String)
            If Not oldfigId Is Nothing Then
                dictionaryFig.Add(oldfigId, prefix + index.ToString())
                figure.SetAttributeValue("id", prefix + index.ToString())
                RenumberFigures(figure, prefix + index.ToString() + ".", ns)
            Else
                figure.SetAttributeValue("id", prefix + index.ToString())
            End If
            index = index + 1
        Next figure
    End Sub
End Module