componentWillMount, componentWillReceiveProps, componentWillUpdate
Unsafe: React has a BUG in future releases, especially after allows asynchronous rendering
Version 16.3
Three cycles to add UNSAFE_ * mark.
UNSAFE_componentWillMount, UNSAFE_componentWillReceiveProps, UNSAFE_componentWillUpdate
Version 16.9
Add or not to add the prefix UNSAFE_ *, can be used. But if you use does not add a prefix UNSAFE_ *, then the browser will issue a warning
Version 17.0
Do not add a prefix to remove UNSAFE_ * life cycle, can only be used to add a prefix UNSAFE_ * life cycle.