Angular 2: How to get the selected value from diff

问题:

I would like to use a <select> in a form to let the user being able to update values among different <option>. I have used the technique from the guide here: https://angular.io/docs/ts/latest/guide/forms.html. Here is the sample I am talking about:

<div class="form-group">
    <label for="type">Type :</label>
    <select class="form-control" [(ngModel)]="order.type" ngControl="type">
        <option *ngFor="#type of types" [value]="type">{{type}}</option>
    </select>
</div>

In my order-details.component I have got an updateOrder() which calls the updateOrder() from myApp.services.

My problem is when I am trying to send the data from the form to the back-end: all the parts with an <input> are OK, but not those with <select> (it returns the original values, and not the one selected).

Does anyone have encountered this or a similar problem? Thanks for your help!

回答1:

There is a way to get the value from different options. check this plunker

component.html

 <select class="form-control" #t (change)="callType(t.value)">
      <option *ngFor="#type of types" [value]="type">{{type}}</option>
    </select>

component.ts

this.types = [ 'type1', 'type2', 'type3' ];
   this.order = {
      type: 'type1'          
  };  

  callType(value){
    console.log(value);
    this.order.type=value;
  }

回答2:

Been tackling this problem for a few hours.

Checked in the (incomplete) documentation to find an item in the NgSelectOption page called "ngValue"

Not sure if this is the intended use but it seemed to work fine.

So instead of using

[value]="item"

Use:

[ngValue]="item"

Just use ngModel on the select and ngModelChange event if you want to do something when it changes.

回答3:

In fact I can't reproduce your problem. I created a plunkr with a very simple form with an input and a select. When I submit the form, I have actual values in the bound object. See this plunkr: https://plnkr.co/edit/5C3agW7QZfcrdt88QzSh?p=preview.

Feel free to tell me if I didn't correctly understand your problem.

Thierry