Typescript 刷新时保持当前名称的Angular

我有一个下拉列表，当我使用它时它可以工作，但它有两个问题:

• 如果我刷新，则下拉菜单中的值为空
• 如果我通过URI访问链接，则下拉菜单为空

我基本上想根据我所在的顺序来保留这个名字.想象一下，在下拉列表中有多个订单， Select 一个就会转到该页面.

// Topbar:

export class AppTopbarComponent implements OnInit {
  items?: MenuItem[];
  orders: Order[] = [];
  filteredOrders: any[] = [];
  selectedOrder: any[] = [];
  displayRoutes: string[] = ['/order'];

  constructor(
    public appMain: AppMainComponent,
    private ordersService: OrderService,
    private router: Router,
    private orderSelectionService: OrderSelectionService
  ) {}

  ngOnInit(): void {
    this.ordersService.getAllOrders().subscribe((orders) => {
      this.orders = orders;
    });

    this.router.events.subscribe((event) => {
      if (event instanceof NavigationEnd) {
        const shouldDisplayDropdown = this.displayRoutes.some((route) => event.url.startsWith(route));
        this.selectedOrder = shouldDisplayDropdown ? this.selectedOrder : [];
      }
    });

    this.orderSelectionService.selectedOrderName$.subscribe((selectedOrderName) => {
      this.selectedOrder = selectedOrderName;
    });
  }

  onOrderSelect(event: any) {
    const selectedOrderId = event.Id;
    this.orderSelectionService.setSelectedOrderName(event || []);
    this.router.navigate(['/order', selectedOrderId, 'home']);
  }
}

// Service:

@Injectable({
  providedIn: 'root',
})
export class OrderSelectionService {
  private selectedOrderSource = new BehaviorSubject<any[]>([]);

  selectedOrderName$: Observable<any[]> = this.selectedOrderSource.asObservable();

  setSelectedOrderName(orderName: any[]) {
    this.selectedOrderSource.next(orderName);
  }
}

到目前为止，我一直在设法弄到这条路由.

this.activatedRoute.params.subscribe((params) => {
  console.log('Route Params:', params);
  const selectedOrderId = params['id'];
  this.selectedOrder = this.orders.find((order) => order.Id === selectedOrderId) || [];
});

但它返回未定义的.

只是需要一些帮助来找出做到这一点的最佳方法.DisplayRoutes，这样做的方法是在不在特定路由上时重置下拉列表.