Can't get treeview control to stay open asp.net

[Proctor]

Hello: I'm working on a small web site and would like to use the treeview control. This is my first time to use a treeview control.

I've embedded the treeview in a master page - and When it first loads, it collapses to show only the primary nodes; If I select one of these, it expands as it should to show the child nodes; however, if I click on a child node to display a page, the child nodes collapse after the page opens.

I'm working with System.Web.UI.WebControls and my tree view is not created dynamically.

I'm trying to work with some of the events such as TreeView1_TreeNodeExpanded but can't seem to get it to work.

I would really appreciate any dirrection you can point me in.

Thanks,
Proctor

[Proctor]

I was able to find the solution on the internet (http://msdn2.microsoft.com/en-us/mag...c163598.aspx):

Imports System
Imports System.Web.UI.WebControls
Imports System.Collections.Generic
Partial Class SiteNavigation
Inherits System.Web.UI.MasterPage
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
' Disable ExpandDepth if the TreeView’s expanded/collapsed 
' state is stored in session. 
If Session("TreeViewState") IsNot Nothing Then
TreeView1.ExpandDepth = -1
End If
End Sub
Protected Sub TreeView1_DataBound(ByVal sender As Object, ByVal e As System.EventArgs) Handles TreeView1.DataBound
If Session("TreeViewState") Is Nothing Then
' Record the TreeView’s current expanded/collapsed state. 
Dim list As New List(Of String)(100)
SaveTreeViewState(TreeView1.Nodes, list)
Session("TreeViewState") = list
Else
' Apply the recorded expanded/collapsed state to 
' the TreeView. 
Dim list As List(Of String) = DirectCast(Session("TreeViewState"), List(Of String))
RestoreTreeViewState(TreeView1.Nodes, list)
End If
End Sub
Protected Sub TreeView1_TreeNodeCollapsed(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.TreeNodeEventArgs) Handles TreeView1.TreeNodeCollapsed
If IsPostBack Then
Dim list As New List(Of String)(100)
SaveTreeViewState(TreeView1.Nodes, list)
Session("TreeViewState") = list
End If
End Sub
 
Protected Sub TreeView1_TreeNodeExpanded(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.TreeNodeEventArgs) Handles TreeView1.TreeNodeExpanded
If IsPostBack Then
Dim list As New List(Of String)(100)
SaveTreeViewState(TreeView1.Nodes, list)
Session("TreeViewState") = list
End If
End Sub
 
 
Private Sub SaveTreeViewState(ByVal nodes As TreeNodeCollection, ByVal list As List(Of String))
' Recursively record all expanded nodes in the List. 
For Each node As TreeNode In nodes
If node.ChildNodes IsNot Nothing AndAlso node.ChildNodes.Count <> 0 Then
If node.Expanded.HasValue AndAlso node.Expanded.Value = True AndAlso Not [String].IsNullOrEmpty(node.Text) Then
list.Add(node.Text)
End If
'If node.Expanded.HasValue AndAlso node.Expanded = True AndAlso Not [String].IsNullOrEmpty(node.Text) Then
' list.Add(node.Text)
'End If
SaveTreeViewState(node.ChildNodes, list)
End If
Next
End Sub
Private Sub RestoreTreeViewState(ByVal nodes As TreeNodeCollection, ByVal list As List(Of String))
For Each node As TreeNode In nodes
' Restore the state of one node. 
If list.Contains(node.Text) Then
If node.ChildNodes IsNot Nothing AndAlso node.ChildNodes.Count <> 0 AndAlso node.Expanded.HasValue AndAlso node.Expanded.Value = False Then
node.Expand()
End If
ElseIf node.ChildNodes IsNot Nothing AndAlso node.ChildNodes.Count <> 0 AndAlso node.Expanded.HasValue AndAlso node.Expanded.Value = True Then
node.Collapse()
End If
' If the node has child nodes, restore their states, too. 
If node.ChildNodes IsNot Nothing AndAlso node.ChildNodes.Count <> 0 Then
RestoreTreeViewState(node.ChildNodes, list)
End If
Next
End Sub
 
 
End Class

I converted to vb and thought I'd post in case it could be useful to anyone.
Thanks,
Proctor