Prevent nodes from being selected

[steven]

I have a RadTreeView bound in an MVVM style application. If a selection does not contain Details I need to disable the ability to click on that node and keep the currently selected node highlighted. The user should still able to expand and collapse.

I have tried to bind to PreviewSelected but the SelectedItem property still gets hit even if I switch e.handled = true and I lose the node highlighting on the currently selected node. 

<UserControl.Resources>

    <ResourceDictionary>

        <Style x:Key="PHToCItemContainerStyle" TargetType="{x:Type telerik:RadTreeViewItem}" BasedOn="{StaticResource RadTreeViewDefaultItemPlusMinusStyle}">

            <Setter Property="IsExpanded" Value="{Binding IsExpanded, Mode=TwoWay}"/>

            <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}"/>

        </Style>

        <DataTemplate x:Key="Measure">

            <TextBlock Text="{Binding Name }" Style="{StaticResource RadTreeViewItemSelectedTextBlockDefaultStyle}" VerticalAlignment="Center"/>

        </DataTemplate>

        <HierarchicalDataTemplate x:Key="Condition" ItemTemplate="{StaticResource Measure}" ItemsSource="{Binding Measures}">

            <TextBlock Text="{Binding Name}" Style="{StaticResource RadTreeViewItemSelectedTextBlockDefaultStyle}" />

        </HierarchicalDataTemplate>

        <HierarchicalDataTemplate x:Key="ConditionGroup" ItemTemplate="{StaticResource Condition}" ItemsSource="{Binding Conditions}" >

            <TextBlock Text="{Binding Name }" FontWeight="Bold" Style="{StaticResource RadTreeViewItemSelectedTextBlockDefaultStyle}" />

        </HierarchicalDataTemplate>

    </ResourceDictionary>

</UserControl.Resources>

 

...

 

<telerik:RadTreeView

    x:Name="RadTree"     

    telerik:TextSearch.TextPath="Name"   

    VirtualizingStackPanel.IsVirtualizing="True"

    VirtualizingStackPanel.VirtualizationMode="Recycling"

    ItemsSource="{Binding ResultObject}"

    Style="{StaticResource RadTreeViewDefaultPlusMinusStyle}"

    ExpanderStyle="{StaticResource RadTreeViewDefaultPlusMinusExpanderStyle}"

    ItemTemplate="{StaticResource ConditionGroup}"

    ItemContainerStyle="{StaticResource PHToCItemContainerStyle}"

    SelectedItem="{Binding ResultObject.SelectedIndexItem}" />

dll version = 2014.1.331.45

[Martin Ivanov]

Hello Steven,

Indeed, when you try the cancel the selection in the PreviewSelection event the previously selection is removed. However, this is not reproducible with the latest version of our controls. Furthermore, we recommend using the PreviewSelectionChanged event instead of the PreviewSelection. If you handle the PreviewSelectionChanged event of the tree, the issue won't be observed.

private void RadTreeView_PreviewSelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
    e.Handled = true;
}

I hope this helps.

Regards,
Martin
Telerik