Element-ui's Select selector switch back

Element-ui's Select selector switch back

Requirement: After selecting a certain school year, you need to ask whether to confirm?

step:

1. Monitor the change when selected, save the old selected id
   
   The selected id is yearId
2. Use @change to switch methods
   
3. Possible problems?
   • After selecting Ask to cancel or confirm, the next box will be re-expanded
   • solve:
     1. define ref
     2. Called after checking to ask to cancel or confirmthis.$refs.selectRef.blur();