Angular 6将值从一个服务传递到另一个服务？

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

@Injectable()
export class DataService {
  private dataSubject = new BehaviorSubject<string>(''); // 创建一个可观察对象
  public data$ = this.dataSubject.asObservable(); // 将可观察对象公开为只读属性

  setData(value: string) {
    this.dataSubject.next(value); // 更新可观察对象的值
  }
}

import { Injectable } from '@angular/core';
import { DataService } from './data.service';

@Injectable()
export class AnotherService {
  constructor(private dataService: DataService) {}

  getValueFromDataService() {
    this.dataService.data$.subscribe(value => {
      console.log(value); // 在控制台打印传递的值
    });
  }
}

import { Component } from '@angular/core';
import { DataService } from './data.service';

@Component({
  selector: 'app-root',
  template: `
    <button (click)="setValue()">Set Value</button>
  `
})
export class AppComponent {
  constructor(private dataService: DataService) {}

  setValue() {
    this.dataService.setData('Hello from AppComponent'); // 更新值
  }
}