public static void OnPrimaryButtonImagePathChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            ToggleMemoryButton button = d as ToggleMemoryButton;

            if (button != null)
            {
                button._button.ImagePath = (string)e.NewValue;
            }
        }
        public static void OnCurrentIndexChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            ToggleMemoryButton button = d as ToggleMemoryButton;

            if (button != null)
            {
                button._label.Content = String.Format(button.DisplayFormat, button.CurrentIndex + 1) + (button.CurrentIndex < 1 ? "" : "s");
                button._selectAll((int)e.NewValue);
            }
        }