RoutedEvent from a class not firing

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I am developing a diagramming project within C# using WPF. I based the
visual representation off a tutorial from CodeProject <a
href=http://www.codeproject .com/KB/WPF/WPFDiagramDesig ner_Part4.aspx" >WPF
Diagram Designer</a>. I've added most of the extensions that I need for the
solution but I'm new to WPF and having trouble getting RoutedEvents to work
correctly.

I have a canvas object which has several designerItems on it. The
DesignerItem class has a RoutedEvent called NewDesignerItem Event which is
fired whenever a new item is created:

<code>
/// <summary>
/// Notify any listeners that a new Designer Item has been created.
/// </summary>
public static readonly RoutedEvent NewDesignerItem Event =
EventManager.Re gisterRoutedEve nt("NewDesigner Item",
RoutingStrategy .Bubble,
typeof(RoutedEv entHandler),
typeof(Designer Item));

public event RoutedEventHand ler NewDesignerItem
{
add { AddHandler(NewD esignerItemEven t, value); }
remove { RemoveHandler(N ewDesignerItemE vent, value); }
}

/// <summary>
/// Fires the NewDesignerItem Event with a reference to this instance
/// of the DesignerItem class
/// </summary>
private void NotifyNewDesign erItem()
{
RoutedEventArgs e = new
RoutedEventArgs (DesignerItem.N ewDesignerItemE vent, this);
RaiseEvent(e);
}

</code>

Within my XAML I have added an EventHandler that should catch all
NewDesignerItem events that are bubbling up:

<code>
<s:DesignerCanv as
Focusable="true "
x:Name="MyDesig ner"

s:DesignerItem. NewDesignerItem ="MyDesigner_Ne wDesignerItem"
Background="{St aticResource
WindowBackgroun dBrush}"
Margin="10" FocusVisualStyl e="{x:Null}"
ContextMenu="{S taticResource
DesignerCanvasC ontextMenu}"/>

</code>

The behavior I am expecting is that whenever the NewDesignerItem event is
fired for a child within the DesignerCanvas object "MyDesigner " that event
will be "bubled up" to my event handler. However, nothing happens! I can
step through the creation of the DesignerItem and verify that my RoutedEvent
is being called but the Handler never gets it.

I was able to get the event handler to fire by using
EventManager.Re gisterClassHand ler() within my Window constructor.
Unfortunately, this implementation doesn't meet my goals because I will
eventually have dozens of Canvas objects and I only want to handle the event
on the canvas that "owns" the newly added DesignerItem.

I did a sanity test by replacing my NewDesignerItem event with the
ButtonBase.Clic k event and trapping that. This implementation works fine and
my EventHandler is called as expected for all buttons contained in my
DesignerCanvas.

<code>

<s:DesignerCanv as
Focusable="true "
x:Name="MyDesig ner"
ButtonBase.Clic k="MyDesignerBu tton_Click"
Background="{St aticResource
WindowBackgroun dBrush}"
Margin="10" FocusVisualStyl e="{x:Null}"
ContextMenu="{S taticResource
DesignerCanvasC ontextMenu}">
</s:DesignerCanva s>

</code>
Thanks in advance!

I'm using Visual Studio 2008 Professional with .NET Framework 3.5 SP1