使用python实现观察者思想

最新推荐文章于 2024-08-04 23:49:00 发布

原创最新推荐文章于 2024-08-04 23:49:00 发布 · 1.1k 阅读

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本文深入探讨了观察者模式的原理与应用，通过代码示例详细解释了如何使用观察者模式来处理对象间的依赖关系，并展示了触发事件与响应事件的具体实现过程。

#coding=utf-8
class Observer(object):

    def __init__(self):
        self.handlersDic = {}
    
    def fireEvent(self, eventKey, **kw):
        """
        触发
        """
        eList = self.handlersDic.get(eventKey,[])
        for handler in eList: handler(**kw)
        
    def un(self,eventKey, handler):
        """
        在事件字典里删除相关方法
        """
        eList = self.handlersDic.get(eventKey,[])
        for i in range(len(eList)-1, -1, -1):
            if eList[i] == handler: del eList[i]
                   
    def on(self,eventKey, handler):
        """
        关联
        """
        eList = self.handlersDic.get(eventKey,[])
        if not eList: self.handlersDic[eventKey] = eList
        eList.append(handler)

if __name__ == '__main__':
    import time
    def eatFood(t):
        print "i am eat food at %s!" %t
    o = Observer()
    o.on("eatingFood", eatFood)
    def singing():
        print "i am singing!"
        t = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(time.time()))
        o.fireEvent("eatingFood", t=t)
    singing()