/// <summary>
/// 手机抽象类，即装饰者模式中的抽象组件类
/// </summary>
public abstract class Phone
{
    public abstract void Print();
}

/// <summary>
/// 苹果手机，即装饰着模式中的具体组件类
/// </summary>
public class ApplePhone:Phone
{
    /// <summary>
    /// 重写基类方法
    /// </summary>
    public override void Print()
    {
        Console.WriteLine("开始执行具体的对象——苹果手机");
    }
}

/// <summary>
/// 装饰抽象类,要让装饰完全取代抽象组件，所以必须继承自Photo
/// </summary>
public abstract class Decorator:Phone
{
    private Phone phone;

    public Decorator(Phone p)
    {
        this.phone = p;
    }

    public override void Print()
    {
        if (phone != null)
        {
            phone.Print();
        }
    }
}

/// <summary>
/// 贴膜，即具体装饰者
/// </summary>
public class Sticker : Decorator
{
    public Sticker(Phone p)
        : base(p)
    { 
    }

    public override void Print()
    {
        base.Print();

        // 添加新的行为
        AddSticker();      
    }

    /// <summary>
    /// 新的行为方法
    /// </summary>
    public void AddSticker()
    {
        Console.WriteLine("现在苹果手机有贴膜了");
    }
}

/// <summary>
/// 手机挂件
/// </summary>
public class Accessories : Decorator
{
    public Accessories(Phone p)
        : base(p)
    {
    }

    public override void Print()
    {
        base.Print();

        // 添加新的行为
        AddAccessories();          
    }

    /// <summary>
    /// 新的行为方法
    /// </summary>
    public void AddAccessories()
    {
        Console.WriteLine("现在苹果手机有漂亮的挂件了");
    }
}

class Customer
{
    static void Main(string[] args)
    {
        // 我买了个苹果手机
        Phone phone = new ApplePhone();

        // 现在想贴膜了
        Decorator applePhoneWithSticker = new Sticker(phone);
        // 扩展贴膜行为
        applePhoneWithSticker.Print();
        Console.WriteLine("----------------------\n");

        // 现在我想有挂件了
        Decorator applePhoneWithAccessories = new Accessories(phone);
        // 扩展手机挂件行为
        applePhoneWithAccessories.Print();
        Console.WriteLine("----------------------\n");

        // 现在我同时有贴膜和手机挂件了
        Sticker sticker = new Sticker(phone);
        Accessories applePhoneWithAccessoriesAndSticker = new Accessories(sticker);
        applePhoneWithAccessoriesAndSticker.Print();
        Console.ReadLine();
    }
}

MemoryStream memoryStream = new MemoryStream(new byte[] {95,96,97,98,99});
// 扩展缓冲的功能
BufferedStream buffStream = new BufferedStream(memoryStream);
// 添加加密的功能
CryptoStream cryptoStream = new CryptoStream(memoryStream,new AesManaged().CreateEncryptor(),CryptoStreamMode.Write);
// 添加压缩功能
GZipStream gzipStream = new GZipStream(memoryStream, CompressionMode.Compress, true);