angular – 如何使用共享服务将数据从一个组件发送到另一个组件

参见英文答案 > How to share service between two modules – @NgModule in angular not between to components?5个
> Angular – shared service between components doesn’t work2个
我想使用subject将数据发送到另一个组件(用于赚钱目的).我无法取回数据.这是我的代码：

app.component.ts

import { Component } from '@angular/core';
import { shareService } from './share.service';

@Component({
 selector: 'my-app',template: `
  <hello></hello>
  <button (click)="passData()">
    Start
  </button>
  `,styleUrls: [ './app.component.css' ],providers:[shareService]
})
export class AppComponent  {
  constructor(private service : shareService){}

  passData(){
   this.service.send("hello");
}

}

hello.component.ts

import { Component,Input } from '@angular/core';
import { shareService } from './share.service';
import { Subscription }   from 'rxjs/Subscription';

@Component({
  selector: 'hello',template: `<h1>Hello!</h1>`,styles: [`h1 { font-family: Lato; }`],providers:[shareService]
})
export class HelloComponent  {
  subscription: Subscription;
    constructor(private share : shareService){
    this.subscription =  share.subj$.subscribe(val=>{
    console.log(val);
    })
  }
}

share.service.ts

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

@Injectable()
export class shareService{

  private sub = new Subject();
  subj$= this.sub.asObservable();

    send(value: string) {
    this.sub.next(value);
  }

}

我没有在控制台中获得价值.

这是工作演示：DEMO

@Component({
  .....
  providers: [shareService]
})

@NgModule({
  ....
  providers: [shareService]
})