Motivation We can not talk about Object Oriented Programming without considering the state of the objects. After all object oriented programming is about objects and their interaction. The cases when certain objects need to be informed about the chan…
The Observer Pattern The Observer is a design pattern where an object (known as a subject) maintains a list of objects depending on it (observers), automatically notifying them of any changes to state. When a subject needs to notify observers about s…
观察者模式(Observer Pattern) 介绍定义对象间的一种一对多的依赖关系,以便当一个对象的状态发生改变时,所有依赖于它的对象都得到通知并自动刷新. 示例有一个Message实体类,某些对象对它的操作有Insert()方法,当发生某些改变的时候,通知所有这些对象并执行Insert()方法. MessageModel using System; using System.Collections.Generic; using System.Text; namespace Pattern.O…
... <?php /* The observer pattern implements a one-too-many dependency between objects. The object that holds the list of dependencies is called subject, while the dependents are called observers. When the subject object changes state, all of the dep…
一,什么是观察者模式(Observer Pattern)? 当对象间存在一对多关系时,则使用观察者模式(Observer Pattern).比如,当一个对象被修改时,则会自动通知它的依赖对象 二,代码如下: 在一开始我们先定义两个类,一个是Chinese类(被观察者) ,另一个是Jan类(观察者),观察者设计模式是当被观察者状态发生改变,从而触发观察者的事件 using System; using System.Collections.Generic; using System.Linq; us…
