如何保存路由器状态并在angular 6中按back按钮返回到路由器状态

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

constructor(private router: Router) { }

ngOnInit() {
  this.router.events
    .pipe(filter(event => event instanceof NavigationEnd))
    .subscribe(() => {
      // 保存当前的路由器状态
      this.saveRouterState();
    });
}

saveRouterState() {
  const routerState = this.router.routerState.snapshot;
  localStorage.setItem('routerState', JSON.stringify(routerState));
}

restoreRouterState() {
  const routerState = JSON.parse(localStorage.getItem('routerState'));
  if (routerState) {
    this.router.navigateByUrl(routerState.url);
  }
}

goBack() {
  // 返回到之前的路由器状态
  this.restoreRouterState();
}