[Solved] Keep dragged/dropped item in listbox selected

[Jeroen]

Hi,

I'm trying to figure out which event is fired when you drag and drop an item within the same listbox?

The actual problem I have is that when I drop my item in the same listbox (I only want to support reordering items in the listbox), the selected item automatically becomes unselected. I want the item that I just dropped to STAY selected. I can't find any property that causes that behaviour, and I can't find any event in which I can handle this myself.

I've tried DragDropManager.AddDragDropCompletedHandler(), DragDropManager.AddDropHandler(), the Drop event... Nothing seems to work.

How should I approach this?

Kind regards,
-- Jeroen

[Nick]

Hi Jeron,

Usually this would be done in the Drop handler. However, if you are using the ListBoxDragDropBehavior, you have to subscribe to the drop event with handledEventsToo set to true.

Let me know if that helps! 

Regards,
Nik
Telerik

[Jeroen]

How do I do that? I'm guessing using AddHandler in code behind, but I can't seem to figure out how to subscribe a DropEvent that way. I'm working in C#.

My listbox is defined as follows:

<telerik:RadListBox ItemsSource="{Binding BitmapComponentModel.ListLayers}" x:Name="LbLayers" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
                                    ScrollViewer.VerticalScrollBarVisibility="Visible" ScrollViewer.HorizontalScrollBarVisibility="Disabled" Margin="2"
                                    Style="{StaticResource RadListBoxStyle}"
                                    SelectedItem="{Binding BitmapComponentModel.SelectedLayer, Mode=TwoWay}" SelectionChanged="LbLayers_SelectionChanged"
                                    SelectionMode="Single"
                                    Background="Black">
                    <telerik:RadListBox.DragVisualProvider>
                        <telerik:ScreenshotDragVisualProvider />
                    </telerik:RadListBox.DragVisualProvider>
                    <telerik:RadListBox.DragDropBehavior>
                        <telerik:ListBoxDragDropBehavior AllowReorder="True"/>
                    </telerik:RadListBox.DragDropBehavior>
                    <telerik:RadListBox.ItemTemplate>
                        <DataTemplate>
                            <!-- ... -->
                        </DataTemplate>
                    </telerik:RadListBox.ItemTemplate>
                </telerik:RadListBox>

[Jeroen]

I figured it out...

DragDropManager.AddDropHandler(LbLayers, OnElementDrop, true);

That seems to work. Thanks!