在Angular中，可以使用Router来实现面包屑导航。默认情况下，Router会追踪导航路径并根据路径生成面包屑。如果不想追踪导航路径，可以使用自定义的面包屑服务来实现。

以下是一个基本的示例：

1. 创建一个面包屑服务：

import { Injectable } from '@angular/core';
import { ActivatedRoute, NavigationEnd, Router } from '@angular/router';
import { filter } from 'rxjs/operators';

@Injectable()
export class BreadcrumbService {
  breadcrumbs: { label: string, url: string }[] = [];

  constructor(private router: Router, private route: ActivatedRoute) {
    this.router.events.pipe(
      filter(event => event instanceof NavigationEnd)
    ).subscribe(() => {
      this.generateBreadcrumbs(this.route.root);
    });
  }

  generateBreadcrumbs(route: ActivatedRoute, url: string = '', breadcrumbs: { label: string, url: string }[] = []): void {
    const children: ActivatedRoute[] = route.children;

    if (children.length === 0) {
      return;
    }

    for (const child of children) {
      const routeUrl: string = child.snapshot.url.map(segment => segment.path).join('/');
      if (routeUrl !== '') {
        url += `/${routeUrl}`;
      }

      const label = child.snapshot.data['breadcrumb'];
      if (label !== undefined) {
        breadcrumbs.push({ label, url });
      }

      this.generateBreadcrumbs(child, url, breadcrumbs);
    }
  }
}

2. 在需要显示面包屑的组件中，使用BreadcrumbService：

import { Component, OnInit } from '@angular/core';
import { BreadcrumbService } from './breadcrumb.service';

@Component({
  selector: 'app-breadcrumb',
  template: `
    
  `
})
export class BreadcrumbComponent implements OnInit {
  breadcrumbs: { label: string, url: string }[] = [];

  constructor(private breadcrumbService: BreadcrumbService) {}

  ngOnInit() {
    this.breadcrumbs = this.breadcrumbService.breadcrumbs;
  }
}

3. 在路由配置中，为需要显示面包屑的路由添加breadcrumb数据：

import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';
import { HomeComponent } from './home.component';
import { AboutComponent } from './about.component';

const routes: Routes = [
  { path: '', component: HomeComponent, data: { breadcrumb: 'Home' } },
  { path: 'about', component: AboutComponent, data: { breadcrumb: 'About' } }
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule { }

4. 在父组件中，添加来显示面包屑。

这样，当导航到不同的路由时，面包屑会根据路由配置中的breadcrumb数据自动生成。