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NodeExpand event fires twice

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niv kfir
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niv kfir asked on 12 Aug 2010, 09:17 PM
Hi,
I'm populating a treeView with: 
 TreeNodeExpandMode.ServerSideCallBack

and:
 <telerik:RadTreeView ID="tvScannedURLs" runat="server" 
            OnNodeExpand="tvScannedURLs_NodeExpand">
</telerik:RadTreeView>

My problem is that the tvScannedURLs.NodeExpand event is fires twice for every expand of a node on the tree.
It has no connection to the PostBack property of the page.

Any idea why?
Thanks,
Niv.

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niv kfir
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answered on 13 Aug 2010, 09:26 AM
I solved this by adding a flag - Set on the first time the event fires,
and reset on page PostBack.

Not very elegant, but works.
Thanks,
Niv.

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Ryan Ewing
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answered on 26 Aug 2010, 07:04 PM
I have this same problem, I don't really understand what you did, but wrapped the entire function with an "If not e.node.hasControls then", If the node calling this has controls, I know the event has already been fired once.

Is there any progress on why this is happening?
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Yana
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answered on 27 Aug 2010, 09:43 AM
Hello,

Could you please paste some sample code which will help us reproduce the issue?

Greetings,
Yana
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Ryan Ewing
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answered on 27 Aug 2010, 09:12 PM
He is a simple example where this happens:

aspx

 

 

<%@ Page Title="" Language="VB" MasterPageFile="~/Research.master" AutoEventWireup="false" CodeFile="treetest.aspx.vb" Inherits="treetest" %>
  
<asp:Content ID="Content1" ContentPlaceHolderID="cHead" Runat="Server">
  
</asp:Content>
  
<asp:Content ID="Content2" ContentPlaceHolderID="cc" Runat="Server">
  
<telerik:RadScriptManager ID="RadScriptManager1" runat="server">
  
</telerik:RadScriptManager>
  
<telerik:RadTreeView ID="RadTreeView1" runat="server" Height="300px" Width="400px" OnNodeExpand="RadTreeView1_NodeExpand">
  
</telerik:RadTreeView>
  
</asp:Content>

 




aspx.vb

Partial Class treetest
  
Inherits System.Web.UI.Page
  
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
  
If Not IsPostBack Then
  
For i As Integer = 0 To 10
  
Dim sectionNode As Telerik.Web.UI.RadTreeNode = New Telerik.Web.UI.RadTreeNode
  
sectionNode.Text = i.ToString
  
sectionNode.Value = i.ToString
  
sectionNode.ExpandMode = Telerik.Web.UI.TreeNodeExpandMode.ServerSideCallBack
  
sectionNode.PostBack = False
  
RadTreeView1.Nodes.Add(sectionNode)
  
Next
  
End If
  
End Sub
  
Protected Sub RadTreeView1_NodeExpand(ByVal sender As Object, ByVal e As Telerik.Web.UI.RadTreeNodeEventArgs) Handles RadTreeView1.NodeExpand
  
Dim sectionNode As Telerik.Web.UI.RadTreeNode = e.Node
  
For i As Integer = 0 To 10
  
Dim pageNode As Telerik.Web.UI.RadTreeNode = New Telerik.Web.UI.RadTreeNode
  
pageNode.Text = sectionNode.Value & i.ToString
  
pageNode.Value = sectionNode.Value & i.ToString
  
sectionNode.Nodes.Add(pageNode)
  
Next
  
'sectionNode.Expanded = True
  
End Sub
  
End Class

if you put a breakpoint on radtreeview1_nodeExpand you will see that is fires twice for each click, also it put the subnodes in twice.

 

 

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Yana
Telerik team
answered on 30 Aug 2010, 11:56 AM
Hello Ryan,

You should subscribe to the event either in the markup or in the code-behind with  "Handles", so please remove one of the these and the event will be fired only once as expected.

Kind regards,
Yana
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niv kfir
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Answers by
niv kfir
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Ryan Ewing
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Yana
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