我正在使用Angular 6，我遇到了关于导航菜单的问题 .

当我单击子项时，在使用routerLinkActive时，只有子项设置为活动而不是父项 .

我想知道如何在Angular 6中选择其子项时将父项类设置为活动状态？

让我们说我点击楼层维护，这是服务的孩子 . 仅楼层维护将设置为活动，但不设置为服务 . 我想在点击任何子项时使用routerLinkActive激活服务按钮 .

导航菜单

<nav class="navbar navbar-expand-lg navbar-light bg-white thick-border-bottom">
  <div class="container">
  <a class="navbar-brand" routerLink=""><img id="logo" class="img-fluid" src="./assets/logo.svg" alt=""></a>
  <button class="navbar-toggler my-3" type="button" data-toggle="collapse" data-target="#navbarNavDropdown" aria-controls="navbarNavDropdown"
    aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>
  <div class="collapse navbar-collapse" id="navbarNavDropdown">
    <ul class="navbar-nav">
      <li class="nav-item">
        <a class="nav-link" routerLink="" routerLinkActive="active" [routerLinkActiveOptions]={exact:true}>Home<span class="sr-only">(current)</span></a>
      </li>
      <li class="nav-item">
        <a class="nav-link" routerLink="/about" routerLinkActive="active">About</a>
      </li>

        <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" routerLink="services" routerLinkActive="active" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true"
          aria-expanded="false">
            Services
          </a>
          <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
            <a class="dropdown-item" routerLink="services/janitorial-services" routerLinkActive="active">Janitorial Services</a>
            <a class="dropdown-item" routerLink="services/floor-maintenance" routerLinkActive="active">Floor Maintenance</a>
            <a class="dropdown-item" routerLink="services/green-cleaning-services" routerLinkActive="active">Green Cleaning</a>
          </div>
        </li>

      <li class="nav-item">
        <a class="nav-link" routerLink="/our-difference" routerLinkActive="active">Our Difference</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" routerLink="/our-clients" routerLinkActive="active">Our Clients</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" routerLink="/contact" routerLinkActive="active">Contact</a>
      </li>
    </ul>
  </div>
  </div>

</nav>

路由模块

import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';
import { AboutComponent } from './frontend/pages/about/about.component';
import { HomeComponent } from './frontend/pages/home/home.component';
import { ServicesComponent } from './frontend/pages/services/services.component';
import { JanitorialServicesComponent } from './frontend/pages/services/subpages/janitorial-services/janitorial-services.component';
import { ServiceAreasComponent } from './frontend/pages/service-areas/service-areas.component';
import { OurClientsComponent } from './frontend/pages/our-clients/our-clients.component';
import { ContactComponent } from './frontend/pages/contact/contact.component';
import { FloorMaintenanceComponent } from './frontend/pages/services/subpages/floor-maintenance/floor-maintenance.component';
import { GreenCleaningServicesComponent } from './frontend/pages/services/subpages/green-cleaning-services/green-cleaning-services.component';
import { OurDifferenceComponent } from './frontend/pages/our-difference/our-difference.component';

const routes: Routes = [
  { path: '', redirectTo: '/', pathMatch: 'full' },
  { path: '', component: HomeComponent },
  { path: 'about', component: AboutComponent },
  { path: 'services', component: ServicesComponent, 
    children: [
      {path: "janitorial-services", component: JanitorialServicesComponent},
      { path: "green-cleaning-services", component: GreenCleaningServicesComponent},
      { path: "floor-maintenance", component: FloorMaintenanceComponent}
    ] 
  },
  { path: 'our-difference', component: OurDifferenceComponent },
  { path: 'our-clients', component: OurClientsComponent },
  { path: 'contact', component: ContactComponent }
];
@NgModule({
  exports: [RouterModule],
  imports: [RouterModule.forRoot(routes)],
})


export class AppRoutingModule { }