Command binding issue in CustomControl: CanExecute() fires, Execute() does not - wpf

Question

I'm binding a button command, in a ControlTemplate, to an Execute() method in a CustomControl. I'm using a RoutedCommand, the CanExecute() fires, but the Execute() never does. When the CustomControl is placed in the main window, the code works as expected. When it is placed in a Usercontrol, I have this issue. I have tried several ways to wire up the buttons Command (RelayCommand etc) but can't seem to figure out what's wrong. Any help is appreciated.
For context, this is a TokenizingTextBox control - an early fork of the Xceed open source version. The button is for deleting the token from the list of tokens.
The complete style of a TokenIten (which contains the button of interest):
<Style TargetType="{x:Type local:TokenItem}">
<Setter Property="Background" Value="#F3F7FD" />
<Setter Property="BorderBrush" Value="#BBD8FB" />
<Setter Property="BorderThickness" Value="1" />
<Setter Property="Cursor" Value="Arrow" />
<Setter Property="Padding" Value="2,1,1,1" />
<Setter Property="Margin" Value="1,0" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:TokenItem}">
<Border Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Padding="{TemplateBinding Padding}"
CornerRadius="0,0,5,5"
Margin="{TemplateBinding Margin}"
>
<StackPanel Orientation="Horizontal" Margin="1" x:Name="myRoot">
<ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" />
<Button Margin="3,0,0,0" Cursor="Hand"
Command="{x:Static local:TokenizedTextBoxCommands.Delete}" CommandParameter="{TemplateBinding TokenKey}"
PresentationTraceSources.TraceLevel="High">
<!--<Button.Template>
<ControlTemplate TargetType="Button">
<ContentPresenter />
</ControlTemplate>
</Button.Template>-->
<Image Source="/Resources/delete8.png" Width="8" Height="8" />
</Button>
</StackPanel>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
The static Command:
public static class TokenizedTextBoxCommands
{
private static RoutedCommand _deleteCommand = new RoutedCommand();
public static RoutedCommand Delete => _deleteCommand;
}
The Custom Control inherits from ItemsControl. In the non-static constructor, we wire up the static delete command to the DeleteToken method:
public TokenizedTextBox()
{
CommandBindings.Add(new CommandBinding(TokenizedTextBoxCommands.Delete, DeleteToken, CanDelete));
}
Finally CanDelete which just sets CanExecute to true:
private void CanDelete(object sender, CanExecuteRoutedEventArgs canExecuteRoutedEventArgs)
{
canExecuteRoutedEventArgs.CanExecute = true;
}
And DeleteToken - functionality omitted, signature is really only important thing here:
private void DeleteToken(object sender, ExecutedRoutedEventArgs e)
{
...
}
So, hopefully this is enough information for anyone interested in providing guidance/suggestions. Thanks.

Answer 1

Little interest here so I hired a Mentor through Pluralsight. The bindings were correct, but the CustomControl had a RichTextBox which was capturing the Mouse Click. We fixed the issue using a Behavior targeting the Button's PreviewMouseDown.