无法在组件之间进行通信(角2)

Question

我有一个场景，我需要在两个组件之间传递数据，请找到下面的组件树场景。

     A
    / \
   B   C
  / \ / \
 D  E F  G

在这里，我需要将数据从G组件传递到位于同一屏幕上的B组件。

服务

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

@Injectable()
export class myCommService {
  private activeTabIndex = new Subject<number>();
  public activeTabIndexs = new Subject<number>();
  activeTab$ = this.activeTabIndex.asObservable();
  selectedCount$=this.activeTabIndexs.asObservable();
  constructor() { }
  fnActiveTabIs(astronaut: number) {
    debugger
    this.activeTabIndex.next(astronaut);
  }
  fnSelected(astronauts: number) {
    debugger
    this.activeTabIndexs.next(astronauts);
  }
}

G构成部分：

import { Component, OnInit, Input } from '@angular/core';
import { myCommService} from '../../../../shared/services/comm.service';
@Component({
  selector: 'app-bl-view-widget-menu',
  templateUrl: './bl-view-widget-menu.component.html',
  styleUrls: ['./bl-view-widget-menu.component.css'],
  inputs: ['id'],
  providers: [myCommService]
})
export class BlViewWidgetMenuComponent implements OnInit {

  isToggle: boolean = true;
  i = 1;
  constructor(private myCommService: myCommService) { }
  id: Number;
  ngOnInit() {

  }

  fn(data, id) {
    debugger
    this.i = this.i + 1;
    // alert(this.i);
    this.myCommService.fnSelected(1);
  }

}

B构成部分：“

import { Component, OnInit } from '@angular/core';
import { Subscription } from 'rxjs/Subscription';
import { myCommService} from '../../shared/services/comm.service';

@Component({
  // moduleId: module.id,
  selector: 'app-bl-filter',
  templateUrl: 'bl-filter.component.html',
  styleUrls: ['bl-filter.component.css'],
  providers: [myCommService]
})
export class BlFilterComponent implements OnInit {
  showInfo: boolean = true;
  activeTabIndex;
  a;
  constructor(
    private myCommService: myCommService
  ) {
    debugger
     myCommService.selectedCount$.subscribe(
       astronauts => {
         this.a = astronauts;
       });


  }

  ngOnInit() {
  }


}

但是在这里，我能够更新服务中的日期，但是在B组件中，我无法从服务中获取数据。没有错误，实际上我无法调试。任何帮助都将不胜感激。

Answer 1

这是因为服务是每个提供者的单例服务

由于您向G和B组件注入了不同的服务实例，因此无法将其存档。

您需要在一个公共模块中提供服务，如

@NgModule({
    imports: [],
    exports: [],
    declarations: [Gcomponent, BComponent], // <-- components declared in same module
    providers: [myCommService], // <--- service provided here
})