c# 裝飾模式

    public interface IPhoneHandle
    {
        void Show();
    }

    public class ApplePhone : IPhoneHandle
    {
        public void Show()
        {
            Console.WriteLine("ApplePhone");
        }
    }

    public class PhoneDecorator:IPhoneHandle
    {
        private IPhoneHandle _myPhone;
        public PhoneDecorator(IPhoneHandle phone)
        {
            _myPhone = phone;
        }

        public PhoneDecorator()
        {
        }

        public virtual void Show()
        {
            if(_myPhone != null)
            {
                _myPhone.Show();
            }
        }
    }

    public class Sticker:PhoneDecorator
    {
        public Sticker(IPhoneHandle phone) : base(phone) { }

        public override void Show()
        {
            Console.WriteLine("with Sticker");
            base.Show();
        }
    }
    public class Accessories : PhoneDecorator
    {
        public Accessories(IPhoneHandle phone) : base(phone) { }

        public override void Show()
        {
            Console.WriteLine("with Accessories");
            base.Show();
        }
    }

<pre name="code" class="csharp">            IPhoneHandle phone = new Accessories(new Sticker(new PhoneDecorator()));
            phone.Show();