Question

我正在使用Angular5，我有一个字段列表，每个字段都有一个名称和FormControl。我尝试使用此代码将控件动态添加到组中，但出现错误。

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});

这是我得到的错误：

错误TypeError： control.setParent不是函数

at FormGroup.registerControl (forms.js:4352)
at FormGroup.addControl (forms.js:4372)
at eval (trade-search.component.ts:142)

Answer 1

代替使用new FormControl()语法，它将起作用：

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);
}

演示：https://stackblitz.com/edit/angular-9vbsgf?file=src%2Fapp%2Fapp.component.ts

Answer 2

使用带as运算符的强制转换时，似乎无法传递或正确设置控件的formState：

 control: [null, []] as FormControl

但是向FormControl构造函数提供任何值将解决此问题：

ngOnInit() {
        this.form = new FormGroup({
            'field1': new FormControl(''),
            'field1': new FormControl('')
        }
        console.log(this.form);
    }

动态创建formGroup

2 个答案: