要在前端隐藏URL，可以使用Angular的路由器来实现。以下是一个示例代码：

app.module.ts:

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { RouterModule, Routes } from '@angular/router';

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

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

@NgModule({
  imports: [BrowserModule, RouterModule.forRoot(routes)],
  declarations: [AppComponent, HomeComponent, AboutComponent],
  bootstrap: [AppComponent]
})
export class AppModule { }

app.component.html:

home.component.ts:

import { Component } from '@angular/core';

@Component({
  template: '
Home
'
})
export class HomeComponent { }

about.component.ts:

import { Component } from '@angular/core';

@Component({
  template: '
About
'
})
export class AboutComponent { }

通过上述代码，你可以在浏览器中访问http://localhost:4200来访问首页，访问http://localhost:4200/about来访问关于页面。这样，URL地址栏上不会显示具体的组件路径，而是通过路由器进行导航隐藏了URL的细节。