Angular 2.0，如何检测子组件上的路由更改

Question

如何检测子组件上的路由更改？。这是我尝试过的方法，但我只看到应用程序组件跟踪路由更改。我希望能够检测到 url 何时从例如MetaDetailView 组件中的#/meta/a/b/c 到#/meta/a/b/c/d。

@RouteConfig([
    { path: '/', name: 'Home', redirectTo: ['Meta']},
    { path: '/meta/...', name: 'Meta', component: MetaMainComponent, useAsDefault: true},
    ...other routes...,
  ])    
export class AppComponent {
    constructor(private _router: Router) {
        _router.subscribe( (url) => console.log("app.url = " + url));
    }
}

@RouteConfig([
    { path: '/*other', name: 'Detail', component: MetaDetailViewComponent, useAsDefault: true},
])
export class MetaMainComponent {
    constructor(private _router: Router) {
        _router.subscribe( (url) => console.log("metamain.url = " + url));
        console.log("MetaMainComponent")
    }
}

export class MetaDetailViewComponent {
    constructor(private _router: Router) {
        _router.subscribe( (url) => console.log("metadetail.url = " + url));
        console.log("MetaDetailViewComponent")
    }
}

谢谢杰斯珀

Answer 1

RC3+解决方案:

constructor(private router: Router) {
  router.events.subscribe(event => {
    if (event.constructor.name === 'NavigationStart') {
      console.log(event.url);
    }
  });
}

或者，您可以使用 filter 筛选 NavigationStart 事件管道(RxJS 6+):

constructor(private router: Router) {
  router.events.pipe(
    filter(event => event instanceof NavigationStart),
  ).subscribe((event: NavigationStart) => {
    console.log(event.url);
  });
}