Angular2 : Property 'controls' does not exist on type 'AbstractControl' . 通过索引访问格式数组中对象的 .control 时出错

Question

我试图在一个 formarray 中推送另一个 formbuilder，但它给了我一个错误，因为我认为在初始化代码时数组中没有项目，因此没有控件。错误是属性“控件”在

之后类型“AbstractControl”上不存在

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

我正在使用 angular 2.0.0-beta.17

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],
      })
    );

Answer 1

您可以使用['controls']代替.controls，如下所示:

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

但为了简化并提供更多可读性，我建议您将其全部更改为:

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