如何在Angular 8中调用另一个组件的方法

Question

I've explain the scenario in Image.

I've one LayoutComponent ,
In which I have 1) LeftMenuComponent and 2) Router-Outlet In side the LeftMenuComponent I've LoyaltyComponent which is coming from Shared Folder .

I want to call LoyaltyComponent ngOnInit method from any component inside RouterOutlet.

Please Note: LoyaltyComponent is inside Shared Folder and OrderListComponent is inside Order Folder.

Is there any way I can call cross component method or all I need is I want to refresh LoyaltyComponent from OrderList Component.

I've tried:

@ViewChild('Loyalty') private loyaltyComponenet : Loyalty;

But it is giving me undefined.

Also from using behaviourSubject, can I directly call ngOnInit of LoyaltyComponent?

LoyaltyComponent.ts

export class Loyalty implements OnInit {

    public loyaltyMet: number;
    public loyaltyThreshold: number;
    public loyaltyBarWidth: number;
    public loyaltyRequired : number;
    constructor() {
    }

    public ngOnInit(): void {     
        this.loyaltyMet = Context.loyaltyMet;
        this.loyaltyThreshold = Context.loyaltyThreshold;
        this.loyaltyRequired = this.loyaltyThreshold - this.loyaltyMet;
        this.loyaltyBarWidth = this.loyaltyMet * 100 / this.loyaltyThreshold;

        if (this.loyaltyRequired < 0) {
            this.loyaltyRequired = 0;
            this.loyaltyBarWidth = 100;
        }
    }
}

Answer 1

I believe Context is being injected via the constructor, is that a service ?

you can have a method on that service saying "refresh" or something, that when triggered, emits a value via a simple subject.

your Loyalty component, can, oninit, subscribe to that subject, and react to it when its triggered.

as long as the Context service is being used as a singleton for all consumers (as in, provided once) you should be good to go.

Answer 2

如果组件是父级和子级，则使用@Input和@Output ，如果不是，则使用EventEmitter这是解决方案https://stackoverflow.com/a/57324581/2762191