角度5下拉保留值

我想点击按钮生成一些字段。字段生成良好,但生成字段中的下拉列表不保留所选的值。它们被推送到数组中,但是值没有显示在表单中。代码如下。

app.component.html(应用程序组件.html)

<form #formRef="ngForm">
  <div *ngFor="let test of mytest; let in=index" class="col-sm-3">
      <div class="form-group"  >
        <select  name="fe[in]" class="form-control" [(ngModel)]="test.name" >
          <option  *ngFor="let f of fields" [value]="f">{{f}}</option>
        </select>
        <br>
        <select name="ty[in]" class="form-control" [(ngModel)]="test.type"> 
          <option  *ngFor="let ty of types" [value]="ty">{{ty}}</option>
        </select><br>
        <input type="text" [(ngModel)]="test.placeholder" name="name{{in}}" class="form-control" #name="ngModel" required />
        <br>
        <input type="text" [(ngModel)]="test.values" name="name{{in}}" class="form-control" #name="ngModel" />
      </div>
      <br />
  </div>
  <button [disabled]="!formRef.form.valid" (click)="add([in])">Add input</button>
</form>
<br />
<br />
{{ mytest | json}}

应用组件.ts

import { Component } from "@angular/core";
import { test } from './test';

  @Component({
  selector: "app-root",
  templateUrl: './app.component.html'
})
export class AppComponent {
  mytest: test[] = [];
  fields: string[] = ['First Name','Last Name','Email Address','Address1 ','Address2 ','City','Postal Code','Province']
  types: string[] = ['text','email','password','dropdown','radio button','check boxes'];

  add(val) {

    this.mytest.push({name: '',type: '',placeholder:'',values:''});

  }
}