Angular 7不同页面的不同菜单

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';

import { HomeComponent } from './home.component';
import { AboutComponent } from './about.component';
import { ContactComponent } from './contact.component';

const routes: Routes = [
  { path: '', component: HomeComponent },
  { path: 'about', component: AboutComponent },
  { path: 'contact', component: ContactComponent }
];

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

<nav>
  <ul>
    <li><a routerLink="/">Home</a></li>
    <li><a routerLink="/about">About</a></li>
    <li><a routerLink="/contact">Contact</a></li>
  </ul>
</nav>

<router-outlet></router-outlet>

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppRoutingModule } from './app-routing.module';

import { AppComponent } from './app.component';
import { HomeComponent } from './home.component';
import { AboutComponent } from './about.component';
import { ContactComponent } from './contact.component';

@NgModule({
  declarations: [
    AppComponent,
    HomeComponent,
    AboutComponent,
    ContactComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }