Angular 2 rc4：无法从表单中获取值

Question

以下是我的代码的一部分。

<form (ngSubmit)="onSubmit(f)" #f="ngForm"> 
      <label for="city">City</label> 
      <input ngControl="cityName" type="text" id="city"> 
      <button type="submit">Add City</button> 
</form> 

export class SearchCity { 
    onSubmit(form: ControlGroup){ 
     console.log(form.value.cityName); 
    } 

它显示Undefined，我怎么能得到的cityName价值？

Answer 1

您必须添加#cityName="ngForm"才能获得cityName值，如下所示。

https://plnkr.co/edit/CvNwKb8lZtIZHcg05lgS?p=preview

<form (ngSubmit)="onSubmit(f.value)" #f="ngForm"> 
       <label for="city">City</label> 
       <input ngControl="cityName" #cityName="ngForm" type="text" id="city"> 
       //added #cityName="ngForm" as you are dealing with ngControl 

       <button type="submit">Add City</button> 
</form> 


onSubmit(myForm){ 
    console.log(myForm.cityName); 
}