Question

I got this simple ListBox with a contextMenu:

<ListBox BorderThickness="1" BorderBrush="Gray" SelectionChanged="TableList_SelectionChanged"   Grid.Column="0" x:Name="TableList">

            <ListBox.ContextMenu>
                <ContextMenu>
                    <MenuItem Click="MenuItem_Click"  Header="Ajouter"/>
                    <MenuItem Click="MenuItem_Click_1" Header="Supprimer"/>
                </ContextMenu>
            </ListBox.ContextMenu>

            <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal">
                        <Image Name="Image" Height="12px" Width="12px" Source="Apply.gif">
                            <Image.Margin>
                                <Thickness Right="10"></Thickness>
                            </Image.Margin>
                        </Image>
                        <TextBlock Text="{Binding Path=Content}" />
                    </StackPanel>
                </DataTemplate>
             </ListBox.ItemTemplate>

        </ListBox>

and I am trying to retrieve the “Image” control in the selected ListBoxItem from the Handler of the context menu action (any action). So the handler is:

 'Dim ListBox As ListBox = DirectCast(sender.Parent, System.Windows.Controls.ContextMenu).PlacementTarget
    Dim ListBox As ListBox = Me.TableList
    Dim myListBoxItem As ListBoxItem = CType(ListBox.ItemContainerGenerator.ContainerFromItem(ListBox.Items.CurrentItem), ListBoxItem)

    ' Getting the ContentPresenter of myListBoxItem
    Dim myContentPresenter As ContentPresenter = FindVisualChild(Of ContentPresenter)(ListBox)

    ' Finding textBlock from the DataTemplate that is set on that ContentPresenter
    Dim myDataTemplate As DataTemplate = myContentPresenter.ContentTemplate

According to this link form MSDN, I could call the “findName” method from the DataTemplate. But The variable “myDataTemplate” is Nothing…

What am I doing wrong?
Thanks

Answer 1

You’re getting content presenter of ListBox instead of ListBoxItem in this line:

Dim myContentPresenter As ContentPresenter = FindVisualChild(Of ContentPresenter)(ListBox)