Angular4 - 如何动态设置选择选项值

typescript
import { Component } from '@angular/core';
@Component({
  selector: 'app-root',
  template: <code>
    <h2>动态设置选择选项值</h2>
    <select [(ngModel)]="selectedColor">
      <option *ngFor="let color of colors" [value]="color">
        {{ color }}
      </option>
    </select>
    
你选择的颜色是: {{ selectedColor }}
  </code>
})
export class AppComponent {
  colors: string[] = ['红色', '蓝色', '绿色', '黄色', '紫色'];
  selectedColor: string;
}