如何知道哪个observable触发器在Rx.Observable.combineLatest中发生了变化

RxJs无法实现这一目标.不过你可以用额外的状态来做:

var trigger = "";

Rx.Observable
  .combineLatest(
    s1.do(function() { trigger = "s1"; }),
    s2.do(function() { trigger = "s2"; }))
  .subscribe(function(){
    // use trigger
  });