Associate select value to ngModel in Angular 4

问题

I'm using Angular4 tyring to associate ngValue to ngModel but getting Null. So kindly help me to connect ngValue to ngModel

<select name="gender" [(ngModel)]="nameForm.gender">
  <option [ngValue]="Male">Male</option>
  <option [ngValue]="Female">Female</option>
  <option [ngValue]="Others">Others</option>
</select>

回答1:

wrap around single quates 'Male'

<select name="gender" [(ngModel)]="nameForm.gender">
    <option [ngValue]="'Male'">Male</option>
    <option [ngValue]="'Female'">Female</option>
    <option [ngValue]="'Others'">Others</option>
 </select>

回答2:

Bind to value attr directly:

<option [value]="'Male'">Male</option>

...note the single quotes inside [value].

回答3:

use [value]

<select [(ngModel)]="nameForm.gender">
    <option [value]="'Male'">Male</option>
    <option [value]="'Female'">Female</option>
    <option [value]="'Others'">Others</option>
</select>

回答4:

In addition to other answers - I would populate options via *ngFor:

<option *ngFor="let item of genders" [ngValue]="item">{{ item }}</option>

And in the component's class simply create genders property like this:

genders: string[] = ['Male', 'Female', 'Others'];

If you want to use different key-value, you can create object array:

[{value: 'male', title: 'Male'}, {value: 'female', title: 'Female'}, ...]

And in your template:

<option *ngFor="let item of genders" [ngValue]="item.value">{{ item.title }}</option>

Last case - if you want to have options in your template, you can simplify binding syntax:

<option ngValue="Male">Male</option>
...

来源：https://stackoverflow.com/questions/51839685/associate-select-value-to-ngmodel-in-angular-4

标签

javascript

angular

forms

select