javascript 如何从嵌套的 FormGroup 添加/删除 FormControl
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How to add/remove FormControl from a nested FormGroup
提问by Apar Adhikari
candidateForm:FormGroup;
constructor(private fBuilder: FormBuilder){ }
ngOnInit(){
this.candidateForm = this.fBuilder.group({
fname: [null, [Validators.required]],
lname: [null, [Validators.required]],
address: this.fBuilder.group({
address1: [null],
address2: [null],
})
})
}
How to add a FormControl named address3to the form group address? And similarly how to remove them from the same FormGroup?
如何address3在表单组中添加一个名为 FormControl 的控件address？同样如何从同一个 FormGroup 中删除它们？
回答by Erex
First you have to get the sub FormGroup from your main FormGroup, and then you could use the addControl and removeControl refrenced in the documentation here: https://angular.io/api/forms/FormGroup.
首先，您必须从主 FormGroup 中获取子 FormGroup，然后您可以使用此处文档中引用的 addControl 和 removeControl：https://angular.io/api/forms/FormGroup 。
So in your case it would be:
所以在你的情况下，它将是：
//Add:
this.candidateForm.get('address').addControl('address3',[]);
//Remove:
this.candidateForm.get('address').removeControl('address2', null);
回答by Ali Adravi
I tried Adhikari answer but could not worked for me, it always throw error:
我尝试了 Adhikari 答案，但对我不起作用，它总是抛出错误：
error TS2339: Property 'addControl' does not exist on type 'AbstractControl'.
His answer helped me to think, and finally I came out with this:
他的回答帮助我思考，最后我得出了这个：
Write a getter property anywhere like this (to get the group):
在任何地方编写一个 getter 属性（以获取组）：
get addressGroup() { return this.candidateForm.get('address'); }
Now wherever you want to add some controls, use like this:
现在，无论您想在何处添加一些控件，都可以像这样使用：
if(this.addressGroup instanceof FormGroup){
var ctrl:AbstractControl = this.fBuilder.control('', [Validators.required]);
(<FormGroup>this.addressGroup).addControl('address3', ctrl);
var emailCtrl:AbstractControl = this.fBuilder.control('', [Validators.email]);
(<FormGroup>this.addressGroup).addControl('myEmail', emailCtrl);
var add4:AbstractControl = this.fBuilder.control('', []);
(<FormGroup>this.addressGroup).addControl('address4', add4);
}
It is an old question, but hope this will help someone!
这是一个老问题，但希望这会对某人有所帮助！
