设计模式-命令模式命令模式的英文翻译是 Command Design Pattern。它是这么定义的:The command pattern encapsulates a request as an object, thereby letting us parameterize other objects with different requests, queue or log requests, and support undoable operations. 翻译一下就是命令模式将请求(命令)封装为一个对象,这样可以