Subroutine AddChildrenToTreeView loops through an XML node's children. For each XML child, it creates a new TreeView node making it the child of the indicated TreeView parent node. If there is no TreeView parent node, it makes the new node have no child so it is a TreeView root node.

After creating the TreeView node, subroutine AddChildrenToTreeView calls itself recursively to add the children of the child node to the tree.

' Load a TreeView control from an XML file.
Private Sub LoadTreeViewFromXmlFile(ByVal file_name As _
    String, ByVal trv As TreeView)
Dim xml_doc As DOMDocument

    ' Load the XML file into the DOMDocument.
    Set xml_doc = New DOMDocument
    xml_doc.Load file_name

    ' Add the root node's children to the TreeView.
    TreeView1.Nodes.Clear
    AddChildrenToTreeView trv, Nothing, _
        xml_doc.documentElement
End Sub

' Add this XML node's children to the indicated TreeView
' node.
Private Sub AddChildrenToTreeView(ByVal trv As TreeView, _
    ByVal treeview_parent As Node, ByVal xml_node As _
    IXMLDOMElement)
Dim xml_child As IXMLDOMElement
Dim new_node As Node

    ' Examine each XML child.
    For Each xml_child In xml_node.childNodes
        ' Add the child to the TreeView.
        If treeview_parent Is Nothing Then
            Set new_node = trv.Nodes.Add(, , , _
                xml_child.nodeName)
        Else
            Set new_node = trv.Nodes.Add(treeview_parent, _
                tvwChild, , xml_child.nodeName)
        End If
        new_node.EnsureVisible

        ' Add the child's children.
        AddChildrenToTreeView trv, new_node, xml_child
    Next xml_child
End Sub