类型"Observable< User>"上不存在属性"switchMap" [英] Property 'switchMap' does not exist on type 'Observable<User>'

问题描述

尝试将switchMap运算符应用于我的Observable时，我收到以下错误消息:

I have been getting the following error message when trying to apply the switchMap operator to my Observable:

可观察"类型不存在属性"switchMap".

Property 'switchMap' does not exist on type 'Observable'.

我当前正在使用rxjs版本5.5.2，在我的组件中，我将其导入为:

I'm currently using rxjs version 5.5.2, and in my component, I have it imported like so:

import 'rxjs/operator/switchMap';

但是，我仍然遇到编译错误.我已经看过类似的问题，却没有找到合适的解决方案，关于这里可能出现的问题有什么建议吗?

However, I still get a compilation error. I have looked at similar questions and have not found a proper solution to this, any suggestions on what could be the issue here?

get appUser$() : Observable<AppUser> {
  return this.user$
    .switchMap(user => {
      if (user) return this.userService.get(user.uid);

      return Observable.of(null);
    });    
}

图片:

推荐答案

如果您使用的是较旧的"patch"样式的运算符，则应从rxjs/add/operator/switchMap导入:

You should be importing from rxjs/add/operator/switchMap if you're using the older "patch" style of operators:

import 'rxjs/add/operator/switchMap';

由于RxJS 5.5具有可点入"运算符，因此您应该从'rxjs/operators'导入:

Since RxJS 5.5 with "pipable" operators you should import from 'rxjs/operators':

import { switchMap } from 'rxjs/operators';

这篇关于类型"Observable< User>"上不存在属性"switchMap"的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！