Angular2 Observable fromEvent keyup map Property＆＃39; key＆＃39;类型＆＃39; {}＆＃39;上不存在

Question

请问，我该如何修复此代码？

Observable.fromEvent(this.getNativeElement(this.term), 'keyup')
    .debounceTime(500)
    .map(ev => ev.key)
    .scan((acc, one) => acc + one)
    .subscribe(term => console.log(term));

我收到错误Property＆＃39; key＆＃39;类型＆＃39; {}＆＃39;上不存在

更新

在@ jb-nizet的评论中（thx这么多:)） 我用

解决了这个问题

Observable.fromEvent<KeyboardEvent>(this.getNativeElement(this.term), 'keyup')

Answer 1

使用

map(ev => ev['key']) 

或告诉TypeScript您的初始Observable是Observable<KeyboardEvent>

const obs: Observable<KeyboardEvent> = Observable.fromEvent(this.getNativeElement(this.term), 'keyup');
obs.debounceTime()...