Angular2进阶之如何避免Dom误区

@Component({ ... })
export class HeroComponent {
 constructor(private _elementRef: ElementRef) {}

 doBadThings() {
  $('id').click(); //jquery
  this._elementRef.nativeElement.xyz = ''; //原生的ElementRef
  document.getElementById('id'); //javascript
 }
}

<div>商品信息</div>
<ul>
 <li *ngFor="let product of dataSource| async as list">
  {{product.title}}
 </li>
</ul>
<div #dia>
</div>

import { Component, OnInit,Renderer2, ViewChild，ElementRef,AfterViewInit} from '@angular/core';
@Component({
 selector: 'app-product',
 templateUrl: './product.component.html',
 styleUrls: ['./product.component.css']
})

export class ProductComponent implements OnInit,AfterViewInit {
 @ViewChild('dia') dia:ElementRef ;定义子试图
 ngOnInit() {
 /**1.
 *创建一个文本
 */
  this.dia.nativeElement.innerHTML="这只是一个测试的文档";

 /**2.
  *添加click事件
  */
 let ul=this.element.nativeElement.querySelector('ul');
  this.render2.listen(ul,"click",()=>{
   this.render2.setStyle(ul,"background","blue");

ngAfterViewInit(){
/**3.
 *修改背景颜色
 */
 let li=this.element.nativeElement.querySelector('ul');
 this.render2.setStyle(li,"background","red");
 }
}