Definition
To do something quickly and often while doing something else, without prior preparation or much thought about how it should be done.
張口就来
We decided to change the presentation flow on the fly during the meeting.
我们在会议期间临时决定改变简报流程。
Due to the time crunch, I had to finish the report on the fly on the plane.
由于时间紧迫，我不得不在飞机上临时完成报告。
Many decisions for this project were made on the fly during execution.
这个项目的许多决定都是在执行过程中临时做出的。
To perform a function without interrupting a computer program that is currently running.
即时（电脑程序）
This software can adjust graphics settings on the fly while the program is running.
这个软件可以在程序运行时即时调整图形设置。
The engineer developed a tool that allows the program to update data on the fly without restarting.
工程师开发了一个工具，可以在不重新启动的情况下即时更新程序数据。
The system can dynamically add server resources on the fly without stopping the service.
系统可以在不停止服务的情况下动态地即时添加服务器资源。