CS

State Intent •Allow an object to alter its behavior when its internal state changes. The object will appear to change its class. applicability An object's behavior depends on its state, an

NULL OBJECT Patterns                    第一次发现此模式时，是由于Bob大叔的经典著作《Agile Principles, Patterns, and Practices In C#》！        下面是出自书中的例子作为引例： Employee e = DB.GetEmployee("Bob"); if (e != nul

Collecting Parameter 场景 You have a single bulky method that accumulates information to a local variable. 你有一个较长方法，其主要为了积累局部信息。 定义 A Collecting Parameter is an object that you pass to method

Intent 目的 Providea way to access the elements of an aggregate object sequentially withoutexposing its underlying representation. 提供一种方法顺序访问一个聚合对象中各个元素, 而又不需暴露该对象的内部表示。 applicability 适应性 to a

Intent Define a family of algorithms, encapsulate each one, and make the minter changeable. Strategy lets the algorithm vary independently from clients that use it. 定义一套算法进行封装，使得可以改变。策略使得算法在调用段可以独立变