装饰模式与子类 [英] Decorator pattern versus sub classing

问题描述

我可以通过添加子类来解决添加功能的问题，那我为什么要使用装饰器模式?装饰器模式的真正优势是什么?

I can solve the problem of adding functionality by adding sub classing then why should I use decorator pattern what's the real advantage of decorator pattern ?

推荐答案

来自 维基百科的装饰模式

装饰者模式可用于使其有可能扩展(装饰)某个对象的功能在运行时.

The decorator pattern can be used to make it possible to extend (decorate) the functionality of a certain object at runtime.

装饰器模式的全部意义在于动态添加额外的行为/功能，这在设计时当然是不可能的.

The whole point of decorator pattern is to dynamically add additional behaviour/functionality, which is of course not possible at design time.

来自同一篇文章:

装饰者模式是一个子类化的替代方法.子类在编译时添加行为时间，而变化影响到所有原始类的实例；装饰可以提供新的行为单个对象的运行时.

The decorator pattern is an alternative to subclassing. Subclassing adds behavior at compile time, and the change affects all instances of the original class; decorating can provide new behavior at runtime for individual objects.

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