在Angular6中,我正在创建一个Injectable
服务。我正在尝试初始化constructor
中的Observable
,请参阅下面的简化代码。
问题:Observable.create
的回调函数从不执行,没有错误。为什么console.log('authObserver created!')
从不打电话?
import { Observable, Observer } from 'rxjs';
@Injectable()
export class UserLoginService implements OnInit{
authObserver:Observer;
authObservable:Observable;
constructor() {
this.authObservable = Observable.create((observer: Observer) => {
this.authObserver = observer;
console.log('authObserver created!')
});
}
}
randomCallbackFunction(){
this.authObserver.next("Button has been clicked");
}
在您的代码中,我没有看到任何订阅发生。可观察量仅在订阅后工作。试试这个
this.authObservable = Observable.create((observer: Observer) => {
this.authObserver = observer;
console.log('authObserver created!')
});
this.authObservable.subscribe()
你可以看到它在这里工作
您需要订阅并保持并关注正确推送新值:
/*
Create an observable that emits 'Hello' and 'World' on
subscription.
*/
const hello = Rx.Observable.create(function(observer) {
observer.next('Hello');
observer.next('World');
});
//output: 'Hello'...'World'
const subscribe = hello.subscribe(val => console.log(val));
看看这个小提琴。