动态表单数组验证Angular 2

Question

我正在从服务响应创建动态FormGroup和FormArray，现在我想验证表单数组，如果任何一个输入有值，否则我不想验证。

this.billingForm = this._fb.group({
   itemRows: this._fb.array([this.initItemRows()])
});

  initItemRows() {
    return this._fb.group({
      Id: '',
      orgName: '',
      billing: this._fb.array([]),
      payment: this._fb.array([])
    });
  }

Answer 1

你可以使用这样的东西：

// Subscribe to value changes on FormGroup
this._fb.valueChanges.subscribe(c => {
    // Check empty values
    if (this._fb.controls['Id'].value !== '' && this._fb.controls['orgName'].value !== '') {
        // Set validators
        this._fb.controls['billing'].validator = Validators.required; // You can specify any validator method here
        this._fb.controls['payment'].validator = Validators.required;
    } else {
        this._fb.controls['billing'].validator = null;
        this._fb.controls['payment'].validator = null;
    }
});

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