角度5在某些部件中有面包屑

在我的angular 5项目中,我尝试为我的组件创建面包屑,我遵循了以下指南 https://medium.com/@bo.vandersteene/angular-5-breadcrumb-c225fd9df5cf

通过瘦面包屑仅显示应用程序组件。html文件,它不会显示在其他组件中。。。我想在某些组件中添加beadcrumb。

例如:

export class BreadcrumbComponent implements OnInit {
    breadcrumbs$;
    // Build your breadcrumb starting with the root route of your current activated route
    constructor(private activatedRoute: ActivatedRoute,
                private router: Router) {
       this.breadcrumbs$ = this.router.events
        .filter(event => event instanceof NavigationEnd)
        .distinctUntilChanged()
        .map(event => this.buildBreadCrumb(this.activatedRoute.root));

    }

    ngOnInit() {
    }

    buildBreadCrumb(route: ActivatedRoute, url: string = '',
                    breadcrumbs: Array<BreadCrumb> = []): Array<BreadCrumb> {
        // If no routeConfig is avalailable we are on the root path
        const label = route.routeConfig ? route.routeConfig.data[ 'breadcrumb' ] : 'Home';
        const path = route.routeConfig ? route.routeConfig.path : '';
        // In the routeConfig the complete path is not available,
        // so we rebuild it each time
        const nextUrl = `${url}${path}/`;
        const breadcrumb = {
            label: label,
            url: nextUrl
        };
        const newBreadcrumbs = [ ...breadcrumbs, breadcrumb ];
        if (route.firstChild) {
            // If we are not on our current path yet,
            // there will be more children to look after, to build our breadcumb
            return this.buildBreadCrumb(route.firstChild, nextUrl, newBreadcrumbs);
        }
        return newBreadcrumbs;
    }
}

html:

<ol class="breadcrumb">
  <li *ngFor="let breadcrumb of breadcrumbs$ | async"
      class="breadcrumb-item">
    <a [routerLink]="[breadcrumb.url, breadcrumb.params]">
      {{ breadcrumb.label }}
    </a>
  </li>
</ol>

我将路由器事件移动到构造函数以检测路由器更改,但它在其他组件中仍然没有显示任何内容 ..在他的代码中,如果我们移动到内容组件,它也不会显示任何内容。

我怎样才能解决这个问题?