摘要： UML:通过让多个对象都有机会处理该请求,来避免耦合请求的发送者的接收器，。链接接收对象并且通过链来传递请求直到一个对象处理它。Avoid coupling the sender of a request to its receiver by giving more than one object a chance to handle the request. Chain the receivin... 阅读全文