RadTreeListView after reload not displaying correctly

[Luzius]

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.

[Luzius]

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?

[Luzius]

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;
    //http://forums.silverlight.net/forums/p/181670/412165.aspx
}

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

[Luzius]

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;
}

[Konstantin]

_ExpNodes - what is it? 

[Luzius]

Hi  Konstantin

_ExpNodes is a member variable and defined as a list of strings.

List<String> _ExpNodes = new List<String>();