应用场景，不同组件中操作统一组数据，不论哪个组件对数据进行了操作，其他组件中立马看到效果。这样他们就要共用一个服务实例，是本次的重点，如果不同实例，那么操作的就不是同一组数据，那么就不会有这样的效果，想实现共用服务实例，就是在所有父组件中priviates:[]中引入这个组件，子组件中不需要再次引入，那么他们都是用的父组件中的服务实例。

1、公用服务

import {Injectable} from "@angular/core";

@Injectable()
export class CommonService {
 public dateList: any = [
 {
 name: "张旭超",
 age: 20,
 address: "北京市朝阳区"
 }
 ];

 constructor() {

 }

 addDateFun(data) {
 this.dateList.push(data);
 }
}

2、parent.component.ts

import {Component, OnInit} from "@angular/core";
import {CommonService} from "./common.service";

// 这里要通过父子公用服务来操作数据，只需要在父组件中引入服务。
@Component({
 selector: "parent-tag",
 templateUrl: "parent.component.html",
 providers: [
 CommonService
 ]
})
export class ParentComponent implements OnInit {
 public list: any = [];

 constructor(private commonService: CommonService) {
 this.list = commonService.dateList;
 }

 ngOnInit() {

 }
}

3、parent.component.html

<table width="500">
 <tr *ngFor="let item of list">
 <td>
 {{item.name}}
 </td>
 <td>
 {{item.age}}
 </td>
 <td>
 {{item.address}}
 </td>
 </tr>
</table>
<child-one-tag></child-one-tag>

4、child-one.component.ts

import {Component} from "@angular/core";
import {CommonService} from "./common.service";

@Component({
 selector: "child-one-tag",
 templateUrl: "child-one.component.html"
})
export class ChildOneComponent {
 public display: boolean = false;
 public username: string = "";
 public age: number = 20;
 public address: string = "";
 constructor(public commonService: CommonService) {

 }

 showDialog() {
 this.display = true;
 }

 hideDialog() {
 this.display = false;
 }

 addInfoFun() {
 let params = {
 name: this.username,
 age: this.age,
 address: this.address
 };
 this.commonService.addDateFun(params);
 params = {};
 }
}

5、child-one.component.html

<p-dialog header="弹窗" [(visible)]="display" [width]="300" appendTo="body" modal="modal">
 <form #myForm="ngForm" name="myForm">
 <p>姓名：<input type="text" name="username" [(ngModel)]="username" pInputText/></p>
 <p>年龄：<input type="number" name="age" [(ngModel)]="age" pInputText/></p>
 <p>地址：<input type="text" name="address" [(ngModel)]="address" pInputText/></p>
 <button pButton label="确定" type="submit" (click)="addInfoFun()"></button>
 <button pButton label="取消" (click)="hideDialog()"></button>
 </form>
</p-dialog>
<button label="添加" pButton (click)="showDialog()"></button>