[Solved] GetClickedElement(Of ListBoxItem) in RadPanelBar

[Lukas]

Hi,

I try to get the ContextMenu.GetClickedElement() Element when clicking on a ListBoxItem, whose ListBox is nested in a RadPanelBarItem.
XAML:

<Canvas>
                <telerikN:RadContextMenu.ContextMenu>
                    <telerikN:RadContextMenu x:Name="contextMenu" ItemClick="contextMenu_ItemClick" Opened="contextMenu_Opened">
                        <telerikN:RadMenuItem Header="Löschen" x:Name="delete"/>
                    </telerikN:RadContextMenu>
                </telerikN:RadContextMenu.ContextMenu>


                <telerikN:RadPanelBar Name="rpb_Vorlagen" HorizontalAlignment="Stretch" Width="505">
                    <telerikN:RadPanelBarItem Header="Administrative Vorlagen" IsExpanded="True" FontWeight="ExtraBold" FontSize="14">
                        <ListBox HorizontalAlignment="Left" Width="498" MaxHeight="215"  Name="lbx_TemplatesAdmin" VerticalAlignment="Top" Background="{StaticResource ControlBrush}">
                            <ListBox.ItemTemplate>
                                <DataTemplate>
                                    <RadioButton GroupName="grp1"  Content="{Binding Name}" Checked="CheckBox_Checked" IsChecked="{Binding isChecked,Mode=TwoWay}" FontWeight="Normal" FontSize="12" />
                                </DataTemplate>
                            </ListBox.ItemTemplate>
                        </ListBox>
                    </telerikN:RadPanelBarItem>
</telerikN:RadPanelBar>

            </Canvas>

I want to get the DataContext of the ListBoxItem clicked. For that I use this Code:

Private Sub contextMenu_Opened(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs)
        Dim buf = Me.contextMenu.GetClickedElement(Of ListBoxItem)()
        If buf IsNot Nothing Then _selectedItem = TryCast(buf.DataContext, DPTemplate)
        If _selectedItem Is Nothing Then
            contextMenuTemplate.IsOpen = False
        End If
    End Sub

But Me.contextMenuTemplate.GetClickedElement(Of ListBoxItem)() always returns nothing!
If I try RadPanelBarItem instead of ListBoxItem for the Type in GetClickedElement i get the ListBox but not the ListBoxItem.

Am I missing something?
How can I retrieve the ListBoxItem clicked in the contextMenue_Open event?

thanks in advance

Lukas

[Hristo]

Hello Lukas,

Could you let us know which Silverlight are you using 3 or 4? Also is there browser zoom?
And let us know which version of the RadControls are you using?
I've created example using your xaml, SL4 and RadControls for Silverlight 4 (2010.1.422.1040) and its working. It is attached.

Let us know if your case is different.

All the best,
Hristo
the Telerik team

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[Lukas]

Hello Hristo ,

thanks for the answer. I looked at your example and compared it to my project.

After a while I found that the only major difference ist the type of added Items.

I have a list of selfwritten class "DPTemplate" and that List is attached to the ItemsSource-Property od the ListBox.
I thought these Items would be added with Type "ListBoxItem" and as DataContext the DPTemplate-Class.

But the added items are of type "Object" (says debugger during runtime). In previous version of my project I used to get all Elements under the cursor and loop through them while TryCasting every found element to  type "DPTemplate", but this doesn't work anymore in the new release of TelerikControls.
(exactly: it still works, but I always have to right-click twice; seems to be due to the new RightClick-Handling in SL 4.0)
So I want to use the new way, but I cannot use GetClickedElement(Of DPTemplate) because DPTemplate does not inherit FrameworkElement.
Could you suggest any way to get these items and cast them to type "DPTemplate" without looping trough all element?
If not I will return to the old way.

Anyway thanks alot so far,

Lukas

[Lukas]

I now found a solution.

I'm still looping through all elements to find the one of the right type.
But due to the contextmenue.opened event is fired before the MouseRightButtonUp event is fired I have to suppred the contextmenue event and fire event manually after the MouseRightButtonU is finished.

    Private Sub OnRightMouseButtonUp(ByVal sender As Object, ByVal e As Windows.Input.MouseButtonEventArgs) Handles Me.MouseRightButtonUp
        Dim mousePosition As Point = e.GetPosition(Nothing)

        For Each item As UIElement In VisualTreeHelper.FindElementsInHostCoordinates(mousePosition, Me)

            Dim buf = TryCast(item, System.Windows.Controls.ListBoxItem)

            If buf IsNot Nothing Then
                _selectedItem = CType(buf.DataContext, DPTemplate)
                contextMenuTemplate.IsOpen = True
                Exit For
            End If
        Next
    End Sub

    Private Sub contextMenu_Opened(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs)  Handles contextMenuTemplate.Opened
        If _selectedItem Is Nothing Then
            contextMenuTemplate.IsOpen = False
        End If
    End Sub

thx

Lukas