也许对事件使用继承层次结构?

Perhaps use an inheritance hierarchy for the Events?

所以你有:

- abstract Event
-- MoveEvent(Direction)
-- FooEvent()
-- BarEvent()

可能更有意义:

- abstract Event
-- abstract MoveEvent
--- MoveUpEvent
--- MoveDownEvent
--- MoveRightEvent
--- MoveLeftEvent
-- FooEvent
-- BarEvent

如果所有的 Move 事件都有一个距离，那么将它传递给 MoveEvent 构造函数(它会向下波动).

If all the Move events have a distance, then pass that into the MoveEvent constructor (which will ripple down).