Compare TreeViews and remove extra items - vb6

Question

Treeview1 has a-z zip names and each zip has child items.
Treeview2 has same zip names but each extra unwanted child items may exist. I need to remove the extra items from Treeview2.

Answer 1

Here's a solution that should work, with useful functions for later in your project:
Private Sub PruneTreeView(ByRef p_objSourceTreeView As TreeView, ByRef p_objTargetTreeView As TreeView)
Dim objSourceNode As Node
Dim objMatchNode As Node
Dim objSourceChildNode As Node
Dim objTargetChildNode As Node
Dim fFound As Boolean
Dim iNodeIndex As Integer
Dim sSummary As String
' Build summary string
sSummary = "Prune TreeView Summary:" & vbCrLf
' Get first node from Source TreeView
Set objSourceNode = p_objSourceTreeView.Nodes(1)
Do While Not objSourceNode Is Nothing
' Check if node has children, otherwise no need to look for match
If objSourceNode.Children > 0 Then
' Find matching node in Target TreeView
Set objMatchNode = GetMatchingNode(p_objTargetTreeView, p_objTargetTreeView.Nodes(1), objSourceNode)
If Not objMatchNode Is Nothing Then
sSummary = sSummary & "Source Node '" & objSourceNode.Text & "' Found in Target." & vbCrLf
' Check all children in Target Node
If objMatchNode.Children > 0 Then
' Set Found flag to False
fFound = False
' Get first Child of Target
Set objTargetChildNode = objMatchNode.Child
Do While Not objTargetChildNode Is Nothing
' Look for match in Source Tree
fFound = Not GetMatchingNode(p_objSourceTreeView, objSourceNode.Child, objTargetChildNode) Is Nothing
' Keep Index reference
iNodeIndex = objTargetChildNode.Index
sSummary = sSummary & "Target Child Node '" & objMatchNode.Text & ":" & objTargetChildNode.Text & "'"
' Go to next sibling
Set objTargetChildNode = GetNextSibling(p_objTargetTreeView, objTargetChildNode)
If fFound Then
sSummary = sSummary & " Found in Target." & vbCrLf
Else
' No Match found
sSummary = sSummary & " Not Found in Target: Deleting at Index " & iNodeIndex & vbCrLf
p_objTargetTreeView.Nodes.Remove iNodeIndex
End If
DoEvents
Loop
End If
End If ' MatchNode exists
End If ' Source Node Children > 0
' Go to next sibling
Set objSourceNode = GetNextSibling(p_objSourceTreeView, objSourceNode)
Loop
End Sub
The following are Helper functions I wrote to handle common tasks while looking up nodes:
Function GetMatchingNode(ByRef p_objTreeView As TreeView, ByRef p_objStartNode As Node, ByRef p_objCompareToNode As Node) As Node
Dim objNode As Node
' Get First Node
Set objNode = p_objStartNode
' Check all Siblings and match on Text property
Do While Not objNode Is Nothing
If objNode.Text = p_objCompareToNode.Text Then
' Match found
Set GetMatchingNode = objNode
Exit Do
Else
Set objNode = GetNextSibling(p_objTreeView, objNode)
End If
Loop
Set GetMatchingNode = objNode
End Function
Function GetNextSibling(ByRef p_objTreeView As TreeView, ByRef p_objNode As Node) As Node
If HasSibling(p_objTreeView, p_objNode) Then
Set GetNextSibling = p_objTreeView.Nodes(GetNextSiblingIndex(p_objNode))
Else
Set GetNextSibling = Nothing
End If
End Function
Function HasSibling(ByRef p_objTreeView As TreeView, ByRef p_objNode As Node) As Boolean
HasSibling = Not (p_objNode.LastSibling Is p_objNode)
End Function
Function GetNextSiblingIndex(ByRef p_objNode As Node) As Integer
With p_objNode
GetNextSiblingIndex = .Index + .Children + 1
End With
End Function

Answer 2

all credits go to Étienne Laneville
Private Sub PruneTreeView(ByRef p_objSourceTreeView As TreeView, ByRef p_objTargetTreeView As TreeView)
Dim objSourceNode As Node
Dim objMatchNode As Node
Dim objSourceChildNode As Node
Dim objTargetChildNode As Node
Dim fFound As Boolean
Dim iNodeIndex As Integer
Dim sSummary As String
' Build summary string
sSummary = "Prune TreeView Summary:" & vbCrLf
' Get first node from Source TreeView
Set objSourceNode = p_objSourceTreeView.Nodes(1)
Do While Not objSourceNode Is Nothing
' Check if node has children, otherwise no need to look for match
If objSourceNode.Children > 0 Then
' Find matching node in Target TreeView
Set objMatchNode = GetMatchingNode(p_objTargetTreeView, p_objTargetTreeView.Nodes(1), objSourceNode)
If Not objMatchNode Is Nothing Then
sSummary = sSummary & "Source Node '" & objSourceNode.Text & "' Found in Target." & vbCrLf
' Check all children in Target Node
If objMatchNode.Children > 0 Then
' Set Found flag to False
fFound = False
' Get first Child of Target
Set objTargetChildNode = objMatchNode.Child
Do While Not objTargetChildNode Is Nothing
' Look for match in Source Tree
fFound = Not GetMatchingNode(p_objSourceTreeView, objSourceNode.Child, objTargetChildNode) Is Nothing
' Keep Index reference
iNodeIndex = objTargetChildNode.Index
sSummary = sSummary & "Target Child Node '" & objMatchNode.Text & ":" & objTargetChildNode.Text & "'"
' Go to next sibling
Set objTargetChildNode = GetNextSibling(p_objTargetTreeView, objTargetChildNode)
If fFound Then
sSummary = sSummary & " Found in Target." & vbCrLf
Else
' No Match found
sSummary = sSummary & " Not Found in Target: Deleting at Index " & iNodeIndex & vbCrLf
p_objTargetTreeView.Nodes.Remove iNodeIndex
End If
DoEvents
Loop
End If
End If ' MatchNode exists
End If ' Source Node Children > 0
' Go to next sibling
Set objSourceNode = GetNextSibling(p_objSourceTreeView, objSourceNode)
DoEvents
Loop
End Sub