Uložení a načtení obsahu TreeView do/ze souboru

Procedury:
Základem jsou dvě procedury -  SaveTree and LoadTree. 
Procedura SaveTree má 3 argumenty:
Jméno souboru (včetně cesty) pro uložení obsahu stromu, název komponenty TreeView  jehož obsah má být uložen a root node - nód, od kterého má začít ukládání. 
Procedura  SaveTree volá privátní proceduru FillPropBag, která vykoná černou práci.

Procedura LoadTree má dva argumenty: jméno souboru, ze kterého se má načíst obsah a jméno komponenty TreeView, do které se obsah uloží.

Private Sub FillPropBag(pb As PropertyBag, _
  tvw As MSComctlLib.TreeView, Root As MSComctlLib.Node)

Static nCount As Long
Dim nde As MSComctlLib.Node
Dim nIndex As Long

If pb Is Nothing Then
Set pb = New PropertyBag
nCount = 0
pb.WriteProperty "NumberOfNodes", tvw.Nodes.Count, 0
End If
On Error Resume Next
pb.WriteProperty "Text" & nCount, Root.Text
nIndex = Root.Parent.Index
If nCount = 0 Then
nIndex = 0
End If
pb.WriteProperty "Parent" & nCount, nIndex, 0
pb.WriteProperty "Key" & nCount, Root.Key, ""
pb.WriteProperty "Index" & nCount, Root.Index, 0
pb.WriteProperty "Image" & nCount, Root.Image, vbEmpty
pb.WriteProperty "SelectedImage" & nCount, _
          Root.SelectedImage, vbEmpty
Set nde = Root.Child
If nde Is Nothing Then
Set nde = Root.Next
If nde Is Nothing Then
Exit Sub
End If
End If
nCount = nCount + 1
FillPropBag pb, tvw, nde
End Sub

Public Sub SaveTree(sFilename As String, _
  tvw As MSComctlLib.TreeView, Root As MSComctlLib.Node)
  
  Dim pb As PropertyBag
  Dim bArr() As Byte
  Dim iFile As Integer

  FillPropBag pb, tvw, Root
  iFile = FreeFile
  Open sFilename For Binary Access Write As #iFile
  bArr = pb.Contents
  Put #iFile, , bArr
  Close #iFile
End Sub

Public Sub LoadTree(sFilename As String, _
  tvw As MSComctlLib.TreeView)
  
  Dim pb As PropertyBag
  Dim bArr() As Byte
  Dim iFile As Integer
  Dim nde As MSComctlLib.Node
  Dim nCount As Long
  Dim nNumOfNodes As Long
  Dim nIndex As Long
  Dim sText$, sKey$
  Dim nParent As Long
  Dim vImage, vSelectedImage

  iFile = FreeFile
  Open sFilename For Binary Access Read As #iFile
  ReDim bArr(LOF(iFile)) As Byte
  Get #iFile, , bArr
  Close #iFile
  Set pb = New PropertyBag
  pb.Contents = bArr
  tvw.Nodes.Clear
  nNumOfNodes = pb.ReadProperty("NumberOfNodes", 0)
  If nNumOfNodes = 0 Then
    Exit Sub
  End If
  Do While nCount < nNumOfNodes
    nParent = pb.ReadProperty("Parent" & nCount, 0)
    nIndex = pb.ReadProperty("Index" & nCount, 0)
    sKey = pb.ReadProperty("Key" & nCount, "")
    sText = pb.ReadProperty("Text" & nCount, "")
    vImage = pb.ReadProperty("Image" & nCount, vbEmpty)
    vSelectedImage = pb.ReadProperty("SelectedImage" _
      & nCount, vbEmpty)
    If nParent Then
      tvw.Nodes.Add tvw.Nodes(nParent), tvwChild, sKey, _
        sText, vImage, vSelectedImage
    Else
      tvw.Nodes.Add , , sKey, sText, vImage, vSelectedImage
    End If
    nCount = nCount + 1
  Loop
End Sub

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