#!/usr/bin/env python

 # -*- coding:utf-8 -*-

 __author__ = 'Andy'

 """

 大话设计模式

 设计模式——状态模式

 状态模式(State Pattern):当一个对象的内在状态改变时允许改变其行为，这个对象看起来像是改变了其类

 应用场景:当控制一个对象的状态转换的条件表达式过于复杂时,把状态的判断逻辑转移到表示不同状态的一系列类当中,可以把复杂的判断逻辑简化

 (当一个对象的行为取决于它的状态,并且它必须在运行时刻根据状态改变他的行为)

 """

 class State(object):

     def __init__(self):

         pass

     def write_program(self, w):

         pass

 class Work(object):

     def __init__(self):

         self.hour = 9

         self.curr = ForenoonState()

     def set_state(self, s):

         self.curr = s

     def write_program(self):

         self.curr.write_program(self)

 class ForenoonState(State):

     def write_program(self, w):

         if w.hour < 12:

             print "当前时间:%s点,"%w.hour,"精神百倍"

         else:

             w.set_state(AfternoonState())

             w.write_program()

 class AfternoonState(State):

     def write_program(self, w):

         if w.hour < 17:

             print "当前时间:%s点,"%w.hour,"状态还行,继续努力"

         else:

             w.set_state(EveningState())

             w.write_program()

 class EveningState(State):

     def write_program(self, w):

         if w.hour < 21:

             print "当前时间:%s点,"%w.hour,"加班呢,疲劳了"

         else:

             w.set_state(SleepState())

             w.write_program()

 class SleepState(State):

     def write_program(self, w):

         print "当前时间:%s点,"%w.hour,"不行了,睡着了"

 if __name__=="__main__":

     work = Work()

     work.hour = 9

     work.write_program()

     work.hour = 15

     work.write_program()

     work.hour = 20

     work.write_program()

     work.hour = 22

     work.write_program()

作者：Andy
出处：http://www.cnblogs.com/onepiece-andy/
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