首先，要确保在每个模块中都要导入RouterModule并调用forChild方法以设置子路由。然后，要在app.module.ts中导入所有模块并调用forRoot方法以设置根路由。 在app.component.html中，使用标记来显示当前路由的内容。 以下是一个示例代码：

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { RouterModule } from '@angular/router';
import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { HomeModule } from './home/home.module';
import { AboutModule } from './about/about.module';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    RouterModule,
    AppRoutingModule,
    HomeModule,
    AboutModule,
    RouterModule.forRoot(AppRoutingModule)
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

app-routing.module.ts

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

const routes: Routes = [
  { path: 'home', loadChildren: () => import('./home/home.module').then(m => m.HomeModule) },
  { path: 'about', loadChildren: () => import('./about/about.module').then(m => m.AboutModule) },
  { path: '', redirectTo: '/home', pathMatch: 'full' }
];

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

home.module.ts

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { HomeComponent } from './home.component';
import { RouterModule } from '@angular/router';

const routes = [
  { path: '', component: HomeComponent }
];

@NgModule({
  declarations: [HomeComponent],
  imports: [
    CommonModule,
    RouterModule.forChild(routes)
  ]
})
export class HomeModule { }

about.module.ts

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { AboutComponent } from