如何在Angular 9中实现CanActivate的保护中使用http请求的结果？

import { HttpClient } from '@angular/common/http';

import { Injectable } from '@angular/core';
import { CanActivate, Router } from '@angular/router';
import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';

@Injectable()
export class AuthGuard implements CanActivate {
  constructor(private http: HttpClient, private router: Router) {}

  canActivate(): Observable<boolean> {
    return this.http.get<boolean>('your-api-url').pipe(
      map((response: boolean) => {
        if (response) {
          return true; // 允许导航到该路由
        } else {
          this.router.navigate(['/unauthorized']); // 导航到未授权页面
          return false;
        }
      })
    );
  }
}

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { AuthGuard } from './auth.guard';

const routes: Routes = [
  { path: 'protected', component: ProtectedComponent, canActivate: [AuthGuard] },
  // 其他路由配置...
];

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