这个错误通常是由于使用过时的 RxJS 版本导致的，特别是 RxJS5 和 RxJS6 中的更改。在最新的版本中，fromPromise 已经被重命名为 from，所以需要使用 from 代替 fromPromise。

下面给出一个示例代码：

import { Injectable } from '@angular/core'; import { HttpEvent, HttpInterceptor, HttpHandler, HttpRequest } from '@angular/common/http'; import { Observable, from } from 'rxjs'; import { switchMap } from 'rxjs/operators';

@Injectable() export class AuthInterceptor implements HttpInterceptor {

constructor() {}

intercept(req: HttpRequest, next: HttpHandler): Observable> {

return from(getToken()).pipe(
  switchMap(token => {

    // Clone the request to add the new header
    const authReq = req.clone({ headers: req.headers.set('Authorization', 'Bearer ' + token) });

    // Pass on the cloned request instead of the original request.
    return next.handle(authReq);
  })
);

} }

function getToken(): Promise { return new Promise(resolve => { // Simulate a delay of 2 seconds before resolving with a token. setTimeout(() => { resolve('my-auth-token'); }, 2000); }); }