使用rxjs5运算符fromEvent时获取“ this”的上下文吗？

Question

How do I get the this context when using fromEvent observable?

window.addEventListener("scroll", function(event) {
    var top = this.scrollY;
   console.log(top)
}, false);

But how do I get it when I do fromEvent?

 Observable.fromEvent(window, 'scroll')
          .subscribe((event) => {
            console.log(this.scrollY);
          });

Answer 1

From mdn :

the value of this inside the handler is a reference to the element. It is the same as the value of the currentTarget property of the event argument that is passed to the handler

So you could just do event.currentTarget.scrollY .