如何在 Angular 6 中观察服务变量

Question

我已经尝试让 Angular 更新服务变量“open_popup”好几天了，但没有成功。

太长了；我想做的是，每当变量“open_popup”发生变化时，使其在组件上发生变化，也能够从组件函数中更改服务变量。

这是我到目前为止所尝试过的。

应用程序/src/app/audience-creator/shared/audience-creator.service.ts

import { Injectable } from "@angular/core";
import {Observable} from "rxjs/index";
import { of } from "rxjs/index";

@Injectable()
export class AudienceCreatorService {
    constructor(private http: HttpClient) {}

    public open_popup = false;

    public toggleCreatorPopup() {
        this.open_popup = !this.open_popup;
    }

    popupIsOpen(): Observable<any> {
        return of(this.open_popup);
    }
}

应用程序/src/app/audience-creator/audience-creator.component.ts

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

@Component({
    selector: 'audience-creator',
    templateUrl: 'audience-creator.html'
})
export class AudienceCreatorComponent implements AfterViewInit, OnInit {

    public popup_is_open = false;

    @Input()
    audience_creator_service;

    ngOnInit() {
        this.audience_creator_service.popupIsOpen().subscribe(
            popup_is_open => this.popup_is_open = popup_is_open
        );
    }
}

应用程序/src/app/audience-creator/audience-creator.html

--> {{ this.popup_is_open }} variable is always false.

不起作用

{{ this.popup_is_open }}

PS：只是尝试将函数直接破解到模板中并且它可以工作，所以我绑定组件变量的方式一定有问题？

{{ audience_creator_service.popupIsOpen().value }}

Answer 1

@Injectable()
export class AudienceCreatorService {
constructor(private http: HttpClient) {}

public open_popup = false
private isOpen: BehaviorSubject<boolean> = new BehaviorSubject(false);

public toggleCreatorPopup() {
    this.open_popup = !this.open_popup;
    this.isOpen.next(this.open_popup);
}

popupIsOpen(): Observable<any> {
    return this.isOpen.asObservable();
}
}