On Wed, 20 Oct 2004 12:47:34 +0200, "Mr.D" <kj**@dlkhdlhjd .com> wrote:
How do I save/load the contents of a Treeview to a file?
I have found several good examples written i VB6, but not a single one for
VB.NET.
Please help.
----
Tim
The following uses a couple of strucures to represent the Treeview in
it's simplest form and then serialization to persist the data to file:
<Code>
<Serializable() > Public Structure TreeViewData
Public Nodes() As TreeNodeData
Public Sub New(ByVal treeview As TreeView)
If treeview.Nodes. Count = 0 Then Exit Sub
ReDim Nodes(treeview. Nodes.Count - 1)
For i As Integer = 0 To treeview.Nodes. Count - 1
Nodes(i) = New TreeNodeData(tr eeview.Nodes(i) )
Next
End Sub
Public Sub PopulateTree(By Val treeview As TreeView)
If Me.Nodes Is Nothing OrElse Me.Nodes.Length = 0 Then Exit
Sub
For i As Integer = 0 To Me.Nodes.Length - 1
treeview.Nodes. Add(Me.Nodes(i) .ToTreeNode)
Next
End Sub
End Structure
<Serializable() > Public Structure TreeNodeData
Public Text As String
Public ImageIndex As Integer
Public SelectedImageIn dex As Integer
Public Nodes() As TreeNodeData
Public Sub New(ByVal node As TreeNode)
Me.Text = node.Text
Me.ImageIndex = node.ImageIndex
Me.SelectedImag eIndex = node.SelectedIm ageIndex
If node.Nodes.Coun t = 0 Then Exit Sub
ReDim Nodes(node.Node s.Count - 1)
For i As Integer = 0 To node.Nodes.Coun t - 1
Nodes(i) = New TreeNodeData(no de.Nodes(i))
Next
End Sub
Public Function ToTreeNode() As TreeNode
ToTreeNode = New TreeNode(Me.Tex t, Me.ImageIndex,
Me.SelectedImag eIndex)
If Me.Nodes Is Nothing OrElse Me.Nodes.Length = 0 Then Exit
Function
For i As Integer = 0 To Me.Nodes.Length - 1
ToTreeNode.Node s.Add(Me.Nodes( i).ToTreeNode)
Next
End Function
End Structure
</Code>
Then to use it:
<Code>
Private SubLoadButton_C lick(ByVal sender As System.Object, ByVal e
As System.EventArg s) Handles Button3.Click
Dim ser As New
System.Xml.Seri alization.XmlSe rializer(GetTyp e(TreeViewData) )
Dim file As New System.IO.FileS tream("C:\Temp\ TreeView.xml",
IO.FileMode.Ope nOrCreate)
Dim writer As New System.Xml.XmlT extWriter(file, Nothing)
ser.Serialize(w riter, New TreeViewData(Tr eeView1))
writer.Close()
file.Close()
file = Nothing
End Sub
Private Sub Button4_Click(B yVal sender As System.Object, ByVal e
As System.EventArg s) Handles Button4.Click
Dim ser As New
System.Xml.Seri alization.XmlSe rializer(GetTyp e(TreeViewData) )
Dim file As New System.IO.FileS tream("C:\Temp\ TreeView.xml",
IO.FileMode.Ope n)
Dim reader As New System.Xml.XmlT extReader(file)
Dim treeData As TreeViewData = CType(ser.Deser ialize(reader),
TreeViewData)
treeData.Popula teTree(TreeView 1)
reader.Close()
file.Close()
file = Nothing
End Sub
</Code>
Hope this helps
Blu.
