An event structure type that contains information about an event exists for every Listener type. When a Listener method is called, an instance of this event is passed to the method as a parameter. Basic Listener methods can also call these event objects, so long as the appropriate parameter is passed in the Sub declaration. For example:
每个收听者类型中都存在一个含有事件信息的事件结构类型。当调用收听者方法时，会将此事件的一个实例作为参数传送到方法。只要子程序声明中传送了相应的参数，Basic 收听者方法就会调用这些事件对象。例如：