通过两次调用服务订阅方法进行Angular 7通信 [英] Angular 7 Communication through service subscribe method called twice

问题描述

我正在使用angular，试图与不是父子组件的组件进行通信.因此，我正在通过服务进行通信

I'm using angular, trying to communicate to a component that is not parent-child. So I'm communicating it through service

service.ts

service.ts

Istoggle=false; 
@Output() change: EventEmitter < boolean > = new EventEmitter();
toggle() {
    this.Istoggle= !this.Istoggle;
    this.toggle.emit(this.Istoggle);
}

search.ts

search.ts

submit():void{
  this.service.toggle();
}

Home.ts

ngOnInit() {    
   this.service.change.subscribe(_toggle=> {
           //some code here
    }
}

因此，当我单击主页"组件中的提交"时，切换订阅会被击中两次

so when I click on submit in Home component toggle subscribe get hit twice

推荐答案

如我所见，您的服务中有3个字段具有完全相同的名称.他们中的两个被错过了.你可以做

as I see you have 3 fields with exact the same name in your service. 2 of them are missed. you could do

value=false; 
search: EventEmitter < boolean > = new EventEmitter();
toggle() {
   this.value = !this.value;
   this.search.emit(this.value);
}

在您的服务和组件中:

ngOnInit() {    
  this.service.search.subscribe(value => {
       //some code here
  }
}

请注意，我删除了@Output()装饰器.它仅在组件内部使用，仅用于父子沟通.

note that I removed @Output() decorator. it is used only inside components just for parent-child communication.

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