Canceling SelectionChanging event and expanding item causes a crash

[Paweł Polaczyk]

I just want to let you know about a bug that I found and I do not really see how to report a bug (and not a feature suggestion) in the issue tracker.

I have a RadTreeListView.
I want to click on an item on the list to expand it.
So that I implemented the following:

<t:RadTreeListView x:Name="radTreeListView" AutoGenerateColumns="False" SelectionChanging="radTreeListView_SelectionChanging">

    <t:RadTreeListView.ChildTableDefinitions>
        <t:TreeListViewTableDefinition ItemsSource="{Binding Children}" />
    </t:RadTreeListView.ChildTableDefinitions>

    <t:RadTreeListView.Columns>
        <t:GridViewDataColumn DataMemberBinding="{Binding Name}" Header="Name" IsReadOnly="True" >
            <t:GridViewDataColumn.CellTemplate>
                <DataTemplate>
                    <Label Content="{Binding Name}"></Label>
                </DataTemplate>
            </t:GridViewDataColumn.CellTemplate>
        </t:GridViewDataColumn>
    </t:RadTreeListView.Columns>

</t:RadTreeListView>

and a handler:

private void radTreeListView_SelectionChanging(object sender, SelectionChangingEventArgs e)
{
    var selectedItem = e.AddedItems.FirstOrDefault();

    e.Cancel = true;

    this.radTreeListView.ExpandHierarchyItem(selectedItem);
}

This causes an exception when I start the application (basically, when the selection is changing).

Removing e.Cancel = true line solves the issue, but well... if I want to cancel this event, then the app crashes.

[Vera]

Hello Paweł,

Thank you for the provided details. We were able to reproduce the problem and will investigate it further. We cannot commit to any specific date or release where the issue will be resolved since it turned out to be not a trivial one and just a check for null will not resolve it.

Please excuse us for the inconvenience caused. Your Telerik points have been updated accordingly.

Regards,
Vera
Telerik