如何在Angular 9中实现router.events的单例订阅

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

@Injectable({
  providedIn: 'root'
})
export class RouterEventsService {
  constructor(private router: Router) { }

  subscribeToRouterEvents() {
    this.router.events.pipe(
      filter(event => event instanceof NavigationEnd)
    ).subscribe((event: NavigationEnd) => {
      // 处理路由事件
      console.log('NavigationEnd event:', event);
    });
  }
}

import { Component, OnInit } from '@angular/core';
import { RouterEventsService } from 'path-to-router-events.service';

@Component({
  selector: 'app-my-component',
  template: '...',
  styleUrls: ['./my-component.component.css']
})
export class MyComponent implements OnInit {
  constructor(private routerEventsService: RouterEventsService) { }

  ngOnInit() {
    this.routerEventsService.subscribeToRouterEvents();
  }
}