publishBehaviour使用BehaviourSubject,并返回ConnectableObservable。connect()方法必须用于订阅创建的可观察对象。
publishBehaviour(defaultvalue)
import { interval} from 'rxjs'; import { take, publishBehavior} from 'rxjs/operators'; let observer = interval(1000).pipe( take(5), publishBehavior(4) ); const subscribe_one = observer.subscribe( x => console.log("Value from Sub1 = "+x) ); const subscribe_two = observer.subscribe( x => console.log("Value from Sub2 = "+x) ); observer.connect(); console.log("After 2 seconds"); setTimeout(() => { const subscribe_three = observer.subscribe( x => console.log("Value from Sub3 = "+x) ); }, 2000);