角度 6 反应形式上的两种方式绑定 [英] Two way binding on angular 6 reactive form

问题描述

我正在尝试创建一个复杂的反应式表单，其中包含填充有数据对象的嵌套组件.

I am trying to create a complex reactive form with nested component that is populated with a data object.

我试图实现的行为与模板驱动表单的双向数据绑定非常相似:当用户编辑表单的输入时，数据对象自动.

The behavior I am trying to achieve is very similar to the two-way data binding of a template-driven form: when the user edits an input of the form, the data object is changing automatically.

但与模板驱动的表单相反，我不能使用 [(ngModel)] 因为它在 angular V6 的反应式表单中已被弃用.

but as opposed to template-driven form, I cannot use [(ngModel)] because it is deprecated in reactive forms for angular V6.

我知道 fromGroup.patchValue() 只会做一种方式绑定，然后我必须手动订阅更改事件并手动更新数据对象 - 这会导致很多累人代码.

I know that fromGroup.patchValue() will only do a one way binding and then ill have to manually subscribe to change events and update the data object manually - this will result in a lot of tiring code.

这种情况有什么解决方法吗?

Is there any workaround for that scenario?

推荐答案

好吧，如果我理解正确的话，我遇到了类似的问题(我真的不知道这是否是最佳实践)但它对我有用，所以在 HTML 中:

Well if I understand you correctly I had a similar problem what I did (I really don't know if this is the best practice)but it's work for me so in the HTML:

<mat-form-field class="mat-container">
    <input matInput  [formControl]="generalDiscount" type="number" 
        formControlName="generalDiscount" 
        (input)="course.amounts.generalDiscount = $event.target.value" <-the workaround 
        placeholder="Discount" required="required">
</mat-form-field>

此输入使其成为双向绑定，并且在您的 .ts 类中，您需要将相同的字段放入表单组中，例如

This input makes it two way binding and in your .ts class you need to put the same field in your form group like

this.amountGroup = this._formBuilder.group({

    [this.course.amounts.fitToNomberOfPeople,Validators.required],
    generalDiscount:[this.course.amounts.generalDiscount,Validators.required],

});

希望能帮到你

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