Save the content in a treeview control to a file...

[Kool Cid]

How can I save the content in a treeview control to a file and..? I also need to know how to get the treeview's content from the file into the control again... Anyone knows how to do this??

[Joacim Andersson]

If you have VB6 you could fill a PropertyBag object and write down the Contents property of the PropertyBag to a file.
I written a Sub called SaveTree that takes three arguments:
A file name, the TreeView control which contents you want to save and the root node of that tree.

The SaveTree sub calles an other sub I called FillPropBag which goes through the tree in a recursive manner.

The LoadTree sub takes two arguments:
The file name and the TreeView control you want to populate.

Here's the code:

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

Good luck!