What if the change event is not triggered when Angular2 assigns a value to the cascading Select?

now the three-level cascade select has been done, but it is found that the change event will not be triggered when assigning values in onInit. How do you handle it in use?

Mar.05,2021

(change) = "selectChange ($event)" change to (ngModelChange) = "selectChange ($event)"
then console.log (event); will do

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b38749-2c11d.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b38749-2c11d.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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