// Part of service
public someEvent: EventEmitter<number> = new EventEmitter();
....
// Component
@Component({
selector: 'some-component',template: `...`
})
export class SomeComponent {
constructor(public service: Service) {
this.service.someEvent.subscribe((x) => {
// Do something
});
}
}
SomeComponent显示在/ route中.当我在我的应用程序中导航到不同的路由,并再次返回时,SomeComponent将再次订阅该事件,导致回调触发两次.如何订阅事件一次或取消订阅销毁组件并再次订阅？
// Can't subscribe after.
ngOnDestroy() {
this.service.someEvent.unsubscribe();
}
对订阅的呼叫返回
instance of
Disposable,其方法为
dispose.
或者如果您使用的是RxJS 5,dispose has been renamed to unsubscribe(感谢@EricMartinez).
…when we’re no longer interested in receiving the data as it comes streaming in,we call dispose on our subscription.
存储您的呼叫结果以订阅,然后在ngOnDestroy中处理订阅.
RxJS 5：
export class SomeComponent {
constructor (public service: Service) {
this.subscription = this.service.someEvent.subscribe((x) => {...});
}
ngOnDestroy () {
this.subscription.unsubscribe();
}
}
RxJS< 5：
export class SomeComponent {
constructor (public service: Service) {
this.subscription = this.service.someEvent.subscribe((x) => {...});
}
ngOnDestroy () {
this.subscription.dispose();
}
}
