angular – TypeError：您在预期的流中提供了“undefined”

doSignup() {
  // set login to same as email
  this.account.login = this.account.email;
  // Attempt to login in through our User service
  this.user.signup(this.account).subscribe((resp) => {
    this.navCtrl.push(MainPage);
  },(err) => {
    //console.log('error in signup',err);
    // ^^ results in 'You provided 'undefined' where a stream was expected'
    //this.navCtrl.push(MainPage);

    // Unable to sign up
    let toast = this.toastCtrl.create({
      message: this.signupErrorString,duration: 3000,position: 'top'
    });
    toast.present();
  });
}

出于某种原因,此代码从不调用成功回调,只调用错误处理程序.如果是这样,它会导致您在上面的评论中看到的错误.

我的user.signup()方法如下所示：

signup(accountInfo: any) {
  return this.api.post('register',accountInfo).share();
}

我的Api类看起来如下：

import { HttpClient,HttpParams } from '@angular/common/http';
import { Injectable } from '@angular/core';

/**
 * Api is a generic REST Api handler. Set your API url first.
 */
@Injectable()
export class Api {
  public static API_URL: string = 'http://localhost:8080/api';

  constructor(public http: HttpClient) {
  }

  get(endpoint: string,params?: any,reqOpts?: any) {
    if (!reqOpts) {
      reqOpts = {
        params: new HttpParams()
      };
    }

    // Support easy query params for GET requests
    if (params) {
      reqOpts.params = new HttpParams();
      for (let k in params) {
        reqOpts.params.set(k,params[k]);
      }
    }

    return this.http.get(Api.API_URL + '/' + endpoint,reqOpts);
  }

  post(endpoint: string,body: any,reqOpts?: any) {
    return this.http.post(Api.API_URL + '/' + endpoint,body,reqOpts);
  }

  put(endpoint: string,reqOpts?: any) {
    return this.http.put(Api.API_URL + '/' + endpoint,reqOpts);
  }

  delete(endpoint: string,reqOpts?: any) {
    return this.http.delete(Api.API_URL + '/' + endpoint,reqOpts);
  }

  patch(endpoint: string,reqOpts);
  }
}

我尝试从user.signup()中删除share(),并返回Observable< any>,但这没有帮助.