改变对ngFor的检测

Question

我在DOM中有2个选择元素。应根据我对第一个选择元素的选择来填充第二个选项。我在这里创建了它的简化版本：https://plnkr.co/edit/tJMjCFp3hQ4PnrGWn3qG?p=preview

@Component({
  selector: 'my-app',
  template: `
    <div>
      <select (change)="setResults($event)">
        <option value='numbers'>Numbers</option>
        <option value='colors'>Colors</option>
      </select>
      <select>
        <option *ngFor = "let op of results" value={{op}}>{{op}}</option>
      </select>
    </div>
  `,
})
export class App {
  name:string;
  constructor() {

  }

  public value: string;
  public result: any[];
  public colors = ['red', 'green', 'blue'];
  public numbers = [1, 2, 3, 4, 5];

  public setResults(e){
    let name = e.target.options[e.target.selectedIndex].value;
    console.log(name);
    if(name === 'numbers'){
      this.result = this.numbers;
      console.log(this.result);
    }
    else
      this.result = this.colors;
  }

}

现在不行。关于什么是错的任何建议？