設計模式學習筆記

最近利用早晨的大好時光，學習了一下設計模式，同時學習了英語。目前一共學習了八種模式：

一、             The Observer Pattern

It defines a one to many relationship between a set of objects. When the state of one object changes, all of its dependents are notified.

二、             The Decorator Pattern

It attaches additional responsibilities to an object dynamically.Decorators provide a flexible alternative to subclassing for extending functionality.

三、             The Factory Pattern

It defines an interface for creating an object, but lets subclasses decide which class to instantiate. Factory method lets a class defer instantiation to subclass.

四、             The Abstract Pattern

It provides an interface for creating families of related or dependent objects without specifying their concrete classes.

五、             The Singleton Pattern

It ensures a class has only one instance, and provides a global point of access to it.

六、             The Command Pattern

It encapsulates a request as an object, thereby letting you parameterize other objects with different requests, queue or log requests, and support undoable operations.

七、             The Adapter Pattern

It converts the interface of a class into another interface the clients expect. Adapter lets classes work together that couldn’t otherwise because of  imcompatible interface.

八、             The Façade Pattern

It provides a unified interface to a set of interfaces in a subsystem. Façade defines a higher-level interface that makes the subsystem easier to use.

在這上述的八個模式中,包含了設計模式的三種類型：創建型模式，結構型模式，行為模式。其中Factory、Abstract Factory、Singleton為創建型模式，Decorator、Adapter、Facade為結構型模式，其余的Command和Observer為行為模式。

不過，感覺有時侯理解的特別清楚，但過一段時間就忘了。所以一定要將其用起來，才能對其有深深的體會，不會就是死的知識。一定要讓其活起來。

呵呵，又看了一些蝸牛的家寫的設計模式趣解，反而更有助于理解呦，不妨看看。鏈接地址為：http://www.shnenglu.com/bangle/archive/2008/08/23/59725.html