等待Angular 2加载/解析FormBuilder/ControlGroups，然后渲染视图/模板 [英] Wait for Angular 2 to load/resolve FormBuilder/ControlGroups before rendering view/template

问题描述

有没有一种方法可以告诉Angular2等到FormBuilder及其元素(及其关联的默认值)已加载，然后渲染模板?

Is there a way to tell Angular2 to wait until a FormBuilder and its elements (with their associated default values) have loaded before rendering the template?

目前我的表单中有以下内容

Currently I have the following in my form

<form (ngSubmit)="submitFees()" [ngFormModel]="FeeForm">
    <div class="form-group row">
      <div class="col-sm-12">
        <input type="number" id="Fees" class="form-control"
        placeholder="Fee" required
       [ngFormControl]="FeeForm.controls['ContentFee']"
        [(ngModel)]="Fee">
      </div>
     Fee: {{postFee*1.2| number:'1.2-2'}}
  </div>
</form>

以及在我的构造函数中:

and in my constructor:

constructor(){
    let fb = new FormBuilder();
    this.FeeForm = fb.group({
        ContentFee: ['0', Validators.required]
    });
}

但是，在页面加载时，在我编辑费用之前，该值显示为NaN，理想情况下，我希望它在页面加载时显示其默认值(0.00).

However on the page load, before I edit the fee the value shows up as NaN, ideally I would like to have it show its default (0.00) on page load.

我该怎么做?

编辑

我注意到，如果用户[(ngModel)]不再提供FormBuilder的默认设置(当我尝试提交空白表单并记录FeeForm.value时，我未定义).周围有没有这个地方?

I notice that if user [(ngModel)] that the defaults of FormBuilder are no longer available (when I try submit a blank form and log the FeeForm.value i get undefined). Is there away around this?

推荐答案

好像您正在RC1中使用不推荐使用的表单，我知道这可以在RC2 +中的新表单中使用

Looks like you are using the deprecated forms in RC1, I know this works with the new forms in RC2+

如果您的组件中有一个Fee字段，则可以在构造函数中设置表单的初始值.

If you have a field Fee in your component you can set the initial value for the form in the constructor.

constructor(){
    this.Fee = 0 // This will show up as the default value 
    let fb = new FormBuilder();
    this.FeeForm = fb.group({
        ContentFee: ['0', Validators.required] // Value not used
    });
}

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