Angular 中可以通过使用 ngTemplateOutlet 指令实现类似于 Vue.js 中 component 的功能，同时也可以使用 ngIf 和 ngSwitch 指令来控制组件的显示和隐藏。而对于 keep-alive 功能，需要在组件内手动管理组件状态和数据的缓存，可以使用 Service 或者 RxJS 等方法实现。

示例代码：

// app.component.html

// app.component.ts import { Component, OnDestroy } from '@angular/core'; import { MyService } from './my.service'; import { Subscription } from 'rxjs';

@Component({ selector: 'app-root', template: '' }) export class AppComponent implements OnDestroy { private subscription: Subscription; private cachedComponent: any;

constructor(private myService: MyService) {}

ngOnInit() { this.subscription = this.myService.getCachedComponent().subscribe((component: any) => { this.cachedComponent = component; }); }

ngOnDestroy() { if (this.subscription) { this.subscription.unsubscribe(); } } }

// my.service.ts import { Injectable } from '@angular/core'; import { Observable, BehaviorSubject } from 'rxjs';

@Injectable({ providedIn: 'root' }) export class MyService { private cachedComponent = new BehaviorSubject(null);

cacheComponent(component: any) { this.cachedComponent.next(component); }

getCachedComponent(): Observable { return this.cachedComponent.asObservable(); } }

// my-component.ts import { Component, OnInit, OnDestroy } from '@angular/core'; import { MyService } from '../my.service';

@Component({ selector: 'my-component', template: '

My Component

ngOnInit() { this.myService.cacheComponent(this); }

ngOnDestroy() { this.myService.cacheComponent(null); } }