从

[formArrayName]="areas" 

并且仅使用

formArrayName="areas"

这是因为您正在尝试使用[ ]绑定变量，而实际上并没有.还要注意您的提交，应该是:

This, because with [ ] you are trying to bind a variable, which this is not. Also notice your submit, it should be:

(ngSubmit)="onSubmit(areasForm.value)"

而不是areasForm.values.