javascript - When using vue $on and $emit to transfer values ​​between two vue files, the value can be printed on the console but not on the page.

Question

Write emit in a.vue

Write $on in b.vue to get

But in b.vue, the value of user_id can be printed on the console, but cannot be printed on the page.

Both vue files have introduced bus, why is this?

Answer 1

Print this to see if it is this of the vue instance