我最近做了类似的事情，这就是我的做法.首先，您需要在应用程序的根目录下创建一个NavBarComponent.在NavBarComponent中，您引用(我称之为)GlobalEventsManager，这是一种您在需要的地方注入的服务.

I recently did something similar and here is how I did it. First, you need to create a NavBarComponent at the root of your app. And in the NavBarComponent you reference (what I call) a GlobalEventsManager which is a service that you inject where you need it.

这里是GlobalEventsManager的一个例子:

Here is a look at the GlobalEventsManager:

import { Injectable } from '@angular/core';
import { BehaviorSubject } from "rxjs/BehaviorSubject";
import { Observable } from "rxjs/Observable";

@Injectable()
export class GlobalEventsManager {

    private _showNavBar: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(false);
    public showNavBarEmitter: Observable<boolean> = this._showNavBar.asObservable();

    constructor() {}

    showNavBar(ifShow: boolean) {
        this._showNavBar.next(ifShow);
    }


}

现在您将GlobalEventsManger服务注入到您的登录组件中(类似这样)

Now you inject the GlobalEventsManger service into your login component (something like this)

import {GlobalEventsManager} from "./../GlobalEventsManager";

@Component({
  selector: 'fnd-login',
  templateUrl: './fnd/login/components/login.component.html',
  providers: [LoginService]
})
export class LoginComponent {
  /* .. other properties */

  constructor(private _router: Router, private _loginService: LoginService, private globalEventsManager: GlobalEventsManager) {
  }
  /* .. other methods  */
  /* .. other methods  */


  private onLoginSuccessfully(data : any) : void {
    /* --> HERE: you tell the global event manger to show the nav bar */
    this.globalEventsManger.showNavBar(true);
    this._router.navigate(['Welcome']);

  }
}

在您的NavBarComponent中，您订阅了showNavBar事件发射器:

In your NavBarComponent you subscribe to the showNavBar Event Emitter:

import {Component, OnInit} from "@angular/core";
import {GlobalEventsManager} from "../GlobalEventsManager";
@Component({
    selector: "navbar",
    templateUrl: "app/main/topNavbar/TopNavbar.html"
})

export class TopNavbarComponent  {
    showNavBar: boolean = false;


    constructor(private globalEventsManager: GlobalEventsManager) { 
        this.globalEventsManager.showNavBarEmitter.subscribe((mode)=>{
            
            this.showNavBar = mode;
        });
        
    }

 
}

在模板HTML中使用* ngIf ="showNavBar"隐藏/显示导航栏.

use *ngIf="showNavBar" in the template HTML to hide/show the Nav bar.

您的应用程序组件如下所示:

Your app component then looks something like this:

@Component({
  selector: 'app',
  template: `<navbar></navbar>
             <router-outlet></router-outlet>
              `
})
export class AppComponent {
  //This doesn't belong here --> public showMenu : boolean;
}

启动应用程序时，还必须注册GlobalEventsManager:

Also the GlobalEventsManager must be registered when you boot the app:

import { GlobalEventsManager } from './GlobalEventsManager';
import { TopNavbarComponent } from './TopNavbarComponent';

@NgModule({
    bootstrap: [App],
    declarations: [
        App,
        TopNavbarComponent
    ],
    imports: [
        BrowserModule
    ],
    providers: [GlobalEventsManager]
})
export class AppModule {
}

应该这样做.

更新:我已经更新了此答案，以反映使用组件外部(即服务中)的事件的更可接受的方式；这需要使用BehaviorSubject/Observable代替EventEmitter

UPDATE: I have updated this answer to reflect the more accepted way of using events outside of a component, ie in a service; which entails using BehaviorSubject/Observable instead of EventEmitter