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，试图与非父子组件通信.所以我通过服务来传达它

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

service.ts

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

search.ts

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

Home.ts

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

所以当我在 Home 组件中点击提交时切换订阅被点击两次

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 个名称完全相同的字段.其中2个被遗漏了.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.它仅用于组件内部，仅用于父子通信.

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

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