Use a TIBEvents component to allow your application to register interest in, and asynchronously handle, events posted by an InterBase server.
In essence, the TIBEvents component allows an application to say "I want to be informed when events X, Y and Z occur."When any of the requested events does occur, the InterBase server notifies the application and OnEventAlert is called.
简而言之,TIBEvents 由InterBase server触发,获取异步事件发生的handle.