Observables often need to be stopped before they are completed. This lesson shows how to use takeUntil to stop a running timer. Then we use the starting stream and the stopping stream together to create a simple stopwatch.
const Observable = Rx.Observable; const startButton = document.querySelector(‘#start‘); const stopButton = document.querySelector(‘#stop‘); const start$ = Observable.fromEvent(startButton, ‘click‘); const interval$ = Observable.interval(1000); const stop$ = Observable.fromEvent(stopButton, ‘click‘); const intervalThatStops$ = interval$ .takeUntil(stop$); start$ .switchMapTo(intervalThatStops$) .subscribe((x)=> console.log(x));
[RxJS] Stopping a Stream with TakeUntil
原文：http://www.cnblogs.com/Answer1215/p/5258721.html