vim file refresh

Question

I have a file that I opened with vim first, and then opened it with UE. I made changes in UE,
If you want to know if there is a corresponding command in vim, you can refresh the open document to the latest content.
Another: What does the :r command in vim mean?
Thanks!

Answer 1

:e!

r means read, reading the contents of another file and inserting it into the current position. Details :help read