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RadTreeListView after reload not displaying correctly

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TreeListView
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Luzius
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Luzius asked on 20 Jan 2011, 11:09 AM

Hi

When I set the ItemsSource of the RadTreeListView the first time after my silverlight 4 app has loaded. The tree is displayed correctly. Including expanded rows.

private void tlvLicMgmt_RowLoaded(object sender, Telerik.Windows.Controls.GridView.RowLoadedEventArgs e)
{
        if (_ExpNodes.Contains(((LicTLstNodeData)e.Row.DataContext).NodeID))
            ((TreeListViewRow)e.Row).IsExpanded = true;
}

If I reload the data the first row is displayed expanded but without showing the subnodes. When I click the first row the arrow changes to collapsed. When I click to expand again, the first two lines are there but almost the rest of the RadTreeListView client region is white only the last two lines are displayed too. When I click on the second node to collaps, everything starts to work fine again.
I work with Version 2010.3.1110.1040.

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Luzius
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answered on 21 Jan 2011, 01:13 PM
This seems to be a problem also if a node contains a large amount of subnodes. I see this behavior also when displaying a result with one top node containing about 500 subnodes (in one level, not sub sub nodes!). Is there another way the restore expanded nodes after load/reload?
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Luzius
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answered on 24 Jan 2011, 01:42 PM
I found a work around by using a DispatcherTimer.

private void tlvSwInv_RowLoaded(object sender, Telerik.Windows.Controls.GridView.RowLoadedEventArgs e)
{
    if (e.Row is TreeListViewRow && e.Row.DataContext is LicTLstNodeData)
    {
        if (_ExpNodes.Contains(((LicTLstNodeData)e.Row.DataContext).NodeID))
        {
            //((TreeListViewRow)e.Row).IsExpanded = true;
            ExpTlvRowDispatcherTimer ExpNodeTimer = new ExpTlvRowDispatcherTimer();
            ExpNodeTimer.Interval = new TimeSpan(0, 0, 0, 0, 2);
            ExpNodeTimer.row = (TreeListViewRow)e.Row;
            ExpNodeTimer.evtHandler = new EventHandler(ExpNodeTimer_Tick);
            ExpNodeTimer.Tick += ExpNodeTimer.evtHandler;
            ExpNodeTimer.Start();
        }
    }
}
void ExpNodeTimer_Tick(object sender, EventArgs e)
{
    ((ExpTlvRowDispatcherTimer)sender).Stop();
    ((ExpTlvRowDispatcherTimer)sender).row.IsExpanded = true;
    ((ExpTlvRowDispatcherTimer)sender).Tick -= ((ExpTlvRowDispatcherTimer)sender).evtHandler;
}


public class ExpTlvRowDispatcherTimer : DispatcherTimer
{
    public TreeListViewRow row { get; set; }
}

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Luzius
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answered on 28 Jan 2011, 08:25 AM
The Telerik support suggested me to used the DataLoaded event to restore expanded nodes.

private void tlvLicMgmt_DataLoaded(object sender, EventArgs e) 
      
    List<string> ExpNodes = new List<string>(_ExpNodes); 
    _ExpNodes.Clear(); 
    foreach (String NodeID in ExpNodes) 
    
        LicTLstNodeData NodeData = GetLicTListNode(NodeID, (ObservableCollection<LicTLstNodeData>)tlvLicMgmt.ItemsSource); 
        if (NodeData != null
        
            DependencyObject dpo = this.tlvLicMgmt.ItemContainerGenerator.ContainerFromItem(NodeData); 
            if (dpo is TreeListViewRow) 
            
                if (!((TreeListViewRow)dpo).IsExpanded) 
                
                    ((TreeListViewRow)dpo).IsExpanded = true
                
            
            else 
            
                tlvLicMgmt.ExpandHierarchyItem(NodeData); 
            
        
    
private LicTLstNodeData GetLicTListNode(String NodeID, ObservableCollection<LicTLstNodeData> SubNodes) 
    foreach (LicTLstNodeData NodeData in SubNodes) 
    
        if (NodeID == NodeData.NodeID) 
            return NodeData; 
        LicTLstNodeData NodeDataSub = GetLicTListNode(NodeID, NodeData.SubNodes); 
        if (NodeDataSub != null
            return NodeDataSub; 
    
    return null
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Konstantin
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answered on 10 Oct 2012, 01:36 PM
_ExpNodes - what is it? 
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Luzius
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answered on 22 Oct 2012, 06:44 AM
Hi  Konstantin

_ExpNodes is a member variable and defined as a list of strings.
List<String> _ExpNodes = new List<String>();

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Konstantin
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