It provides an event handler for each menu option.
它为每一个菜单选项提供事件处理程序。
2
If the option to persist all event data is selected it will be placed here.
如果选择了持久化所有事件数据的选项，则会将该竖井放在此处。
3
By default, the event monitors are created with the AUTOSTART option, which means that the event monitors are automatically started the next time the database is activated.