angular - 如何在 Angular 2 Material 设计的 md-select 组件上设置默认值？

Question

我有以下选择组件，它从来自 rest api 的数据中填充。如何在 md-select 上设置默认选择值？

  <md-select
                placeholder= "Warehouse"
                style="width: 100%"
                [(ngModel)]='selectedProductWarehouse.warehouse'
                name="Warehouse"
                required
                #Warehouse="ngModel">
          <md-option *ngFor="let warehouse of warehouses" [value]="warehouse">{{warehouse.description}}</md-option>
        </md-select>

Answer 1

你可以试试下面，

组件 HTML

  <md-select placeholder="Favorite food" [(ngModel)]="selectedValue" name="food">
    <md-option *ngFor="let food of foods" [value]="food.value" >
      {{food.viewValue}}
    </md-option>
  </md-select>

  <p> Selected value: {{selectedValue}} </p>

组件脚本

@Component({
  selector: 'select-form-example',
  templateUrl: './select-form-example.html',
})
export class SelectFormExample {
  foods = [
    {value: 'steak-0', viewValue: 'Steak'},
    {value: 'pizza-1', viewValue: 'Pizza'},
    {value: 'tacos-2', viewValue: 'Tacos'}
  ];


   // setting this is the key to initial select.
   selectedValue: string = this.foods[0].value;
}

这里的关键是给selectedValue设置初始值。

检查这个StackBlitz .

希望这对您有所帮助!