Author of the article: Caspian
Source Website: https://blog.csdn.net/WangPaiFeiXingYuan
Introduction:
UG\NX secondary development program exit, initialization and termination
exit (User Exit)
User Exit is an important concept in UG/Open API. During the running process of UG, there are specified exits in some specific locations. When the process executes to these exits, UG will automatically check whether the user has defined an environment pointing to the location of the internal UF program. If it is not defined, it will continue to run in the default mode of UG; if it is defined, it will automatically run the user-developed program from there. This process is called User Exit.
Utilizing different User Exit allows user programs to be automatically executed when the UG runs to a specific point. Different entries have different User Exit names, and user programs use different User Exit as exit points to determine which stage of the UG process the program is automatically activated and run.
Each User Exit has a unique exit name, so that the user can call it in the subroutine. When UG executes to a certain exit, it will look for the corresponding User Exit function name in the user program. If it exists, call the function and execute it. Function body, if it does not exist, continue the UG default process.
The most commonly used User Exit is ufsta() and ufusr(), and UF_exit.