Microsoft.Windows.Controls.Ribbon.RibbonMenuButton.HandleMouseButton C# (CSharp) Метод

        protected override void HandleMouseButton(MouseButtonEventArgs e)
        {
            FrameworkElement source = e.OriginalSource as FrameworkElement;
            if (source != null && (source == this || source.TemplatedParent == this))
            {
                e.Handled = true;
            }
        }