public override void SetAlpha(int dwAlpha)
 {
     base.SetAlpha(dwAlpha);
     _imageFocused.SetAlpha(dwAlpha);
     _imageNonFocused.SetAlpha(dwAlpha);
     _imageAlternativeFocused.SetAlpha(dwAlpha);
     _imageAlternativeNonFocused.SetAlpha(dwAlpha);
 }
        /// <summary>
        /// Changes the alpha transparency component of the colordiffuse.
        /// </summary>
        /// <param name="dwAlpha">The new value of the colordiffuse.</param>
        public override void SetAlpha(int dwAlpha)
        {
            base.SetAlpha(dwAlpha);
            _imageFocused.SetAlpha(dwAlpha);
            _imageNonFocused.SetAlpha(dwAlpha);

            if (_hoverImage != null)
            {
                _hoverImage.SetAlpha(dwAlpha);
            }
        }