关于angular：Angular2：类型’AbstractControl’上不存在属性’controls’。通过索引访问formarray中的对象的.control时出错

Angular2: Property 'controls' does not exist on type 'AbstractControl'. Error when accessing .control of an object within a formarray thru an index

我正在尝试在formarray中推送另一个formbuilder，但这给我一个错误，因为我认为初始化代码时数组中没有项目，因此没有控件。错误是属性'controls'在类型'AbstractControl'之后不存在

1	(<FormArray>this.loanTypeForm.controls['frequency']).controls[index]

我正在使用角度2.0.0-beta.17

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let settingsForm: FormArray = new FormArray([]);
(<FormArray>this.loanTypeForm.controls['frequency']).push(
this.formBuilder.group({
'name': [value, Validators.required],
'settings': settingsForm,
})
);
(<FormArray>this.loanTypeForm.controls['frequency']).controls[index].controls['settings'].push(
this.formBuilder.group({
'term': [null, Validators.required],
'eir': [null, Validators.required],
})
);

您可以使用['controls']代替.controls，如下所示：

1	(<FormArray>this.loanTypeForm.controls['frequency']).controls[index]['controls']['settings'].push(...)

但是为了简化并提供更高的可读性，建议您将其全部更改为：

1 2	const control = this.loanTypeForm.get(`frequency.${index}.settings`) as FormArray; control.push(...);

相关讨论

get()是访问表单控件的首选方法

1	this.loanTypeForm.get(`frequency.${index}.settings`)

看来loanTypeForm被视为AbstractControl ...所以让我们向编译器保证它是FormGroup

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var group = this.loanTypeForm as FormGroup;
var array = group.controls['frequency'] as FormArray;
var control = group.controls[index]; // AbstractControl again.. could be casted as needed

如果该控件也是组或形式，我们也只需要使用assert(cast)

1	var control = group.controls[index] as FormGroup

然后我们可以轻松地继续

1	control.controls['settings']...