Angular2路由器监听参数变化

Question

我有几个链接导航为

http://localhost:4200/#/forward/services/our-services?category=1
http://localhost:4200/#/forward/services/our-services?category=2
http://localhost:4200/#/forward/services/our-services?category=3

我想获取类别的值

我试过了

this.sub = this._activatedRoute.params.subscribe(params => {

  this.category = + params['category'];

  console.log(params['category']);

});

console.log() 只打印一次，

我如何确保在类别值发生变化时捕获

这是用来导航的

<ul id="menu-services-menu" class="menu" *ngFor="let category of categories">
 <li><a routerLinkActive="active" [routerLink]="['/forward/services/our-services']" [queryParams]="{ category: category.category }" >{{category.category}}</a></li>

  </ul>

Answer 1

constructor(router:Router, route:ActivatedRoute) {
  router.events
  filter(e => e instanceof NavigationEnd) 
  .forEach(e => console.log(route.snapshot.params['category']);
}