java 全局变量 访问_如何在组件之间获取和设置/访问和修改全局变量

在缺少直接连接的组件之间传递数据时，例如兄弟姐妹，孙子孙等，您应该使用共享服务 .

您可以尝试以下代码段 .

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

import { BehaviorSubject } from 'rxjs/BehaviorSubject';

@Injectable()

export class SharedService {

private messageSource = new BehaviorSubject("list");

currentMessage = this.messageSource.asObservable();

constructor() { }

changeMessage(message: string) {

this.messageSource.next(message)

}

}

//器Comp1

import { Component, OnInit } from '@angular/core';

import {SharedService} from '../shared.service';

@Component({

selector: 'app-comp1',

templateUrl: './comp1.component.html',

styleUrls: ['./comp1.component.css']

})

export class Comp1Component implements OnInit {

message:string;

constructor(private data: SharedService) {

}

ngOnInit() {

this.data.currentMessage.subscribe(message => this.message = message)

console.log(this.message);

}

}

//器Comp2

import { Component, OnInit } from '@angular/core';

import {SharedService} from '../shared.service';

@Component({

selector: 'app-comp2',

templateUrl: './comp2.component.html',

styleUrls: ['./comp2.component.css']

})

export class Comp2Component implements OnInit {

message:string;

constructor(private data: SharedService) { }

ngOnInit() {

this.data.currentMessage.subscribe(message => this.message = message)

console.log(this.message);

}

}