Why doesn't button click event “bubble up visual tree” to StackPanel as MSDN article states?

Question

In the MSDN article Understanding Routed Events and Commands In WPF, it states

an event will bubble (propagate) up the visual tree from the source ele

Answer 1

As others have said, it's because the MouseDown event gets handled by the Button before it can be bubbled further. You can see this in Reflector, in ButtonBase.OnMouseLeftButtonDown:

protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e)
{
    if (this.ClickMode != ClickMode.Hover)
    {
        e.Handled = true;
        // SNIP...
    }
    base.OnMouseLeftButtonDown(e);
}

One solution is to listen for a MouseDown event, and indicate that you don't care if the event is handled. You can do this with the AddHandler method. It has a boolean overload that lets you listen for events which are already handled.

If you do this somewhere instead of setting the MouseDown handler in XAML:

TheStackPanel.AddHandler(MouseDownEvent, new MouseButtonEventHandler(TheStackPanel_MouseDown), true);

You'll receive all MouseDown events on TheStackPanel, regardless of whether they've been handled.