问题
I'm using Angular5, and I have a list of fields, each has a name and FormControl. I try to dynamically add the controls to the group, using this code, but I got an error.
const formControlFields = [
{name: 'field1',control: [null, []] as FormControl},
{name: 'field2',control: [null, []] as FormControl}
];
const formGroup: FormGroup = new FormGroup({});
formControlFields.forEach( f => formGroup.addControl(f.name,f.control));
this.form = new FormGroup({groups:formGroup});
This is the error I get:
ERROR TypeError: control.setParent is not a function
at FormGroup.registerControl (forms.js:4352) at FormGroup.addControl (forms.js:4372) at eval (trade-search.component.ts:142)
回答1:
Instead use the new FormControl()
syntax and it will work:
ngOnInit() {
const formControlFields = [
{ name: 'field1', control: new FormControl(null, []) },
{ name: 'field2', control: new FormControl(null, []) }
];
const formGroup: FormGroup = new FormGroup({});
formControlFields.forEach(f => formGroup.addControl(f.name, f.control));
this.form = new FormGroup({ groups: formGroup });
console.log(this.form);
}
Demo: https://stackblitz.com/edit/angular-9vbsgf?file=src%2Fapp%2Fapp.component.ts
回答2:
Seems like formState for control is not passed or correctly set when using casting with as operator:
control: [null, []] as FormControl
However providing any value to FormControl constructor will solve the issue:
ngOnInit() {
this.form = new FormGroup({
'field1': new FormControl(''),
'field1': new FormControl('')
}
console.log(this.form);
}
来源:https://stackoverflow.com/questions/51209125/control-setparent-is-not-a-function-when-dymanically-creating-formgroup