Javascript 网络错误：req.headers.forEach Apollo客户端Angular4

正在尝试使用Apollo客户端提供的Apollo Client.query调用查询我的graphql端点，该端点可以通过postman调用访问，并返回结果。按照文档中的指导原则，我应该能够在定制的angular 4组件中快速、粗略地执行以下操作：

import { Component } from '@angular/core';
import { AuthService } from '../services/auth.service';
import { User } from '../models/user';

import { Apollo } from 'apollo-angular';

import gql from 'graphql-tag';

@Component({
  selector: 'app-login',
  templateUrl: './login.component.html',
  styleUrls: ['./login.component.css']
})
export class LoginComponent  {
  user: User = new User();
  constructor(private auth: AuthService, private apollo: Apollo) {}
  onLogin(): void {

    this.apollo.query({
      context: {
        headers: {
            'Content-Type': 'application/json',
            'Accept': 'application/json',
        },
        opts: {

          mode: 'no-cors',
        }
      },
      query: gql`{
  allUsers {
    id
    emailAddress
    password
  }
}`}).subscribe(
      (response) => console.log(response),
      (error) => console.log(error),
      () => console.log('completed!')
    );
  }
}

在我的主app.module.ts中创建以下Apollo客户端

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { RouterModule } from '@angular/router';
import {HttpClientModule} from '@angular/common/http';
import { FormsModule } from '@angular/forms';


import { AppComponent } from './app.component';
import { HeaderComponent } from './header/header.component';
import { LoginComponent } from './login/login.component';
import { AuthService } from './services/auth.service';
import { RegisterComponent } from './register/register.component';
import { StatusComponent } from './status/status.component';

import { ApolloModule, Apollo } from 'apollo-angular';
import { HttpLinkModule, HttpLink } from 'apollo-angular-link-http';
import { InMemoryCache } from 'apollo-cache-inmemory';

@NgModule({
  declarations: [
    AppComponent,
    HeaderComponent,
    LoginComponent,
    RegisterComponent,
    StatusComponent
  ],
  imports: [
    BrowserModule,
    HttpClientModule,
    FormsModule,
    ApolloModule,
    HttpLinkModule,
    RouterModule.forRoot([
      { path: 'login', component: LoginComponent },
      { path: 'register', component: RegisterComponent },
      { path: 'status', component: StatusComponent }
    ])

  ],
  providers: [AuthService],
  bootstrap: [AppComponent]
})
export class AppModule {

  constructor(
    apollo: Apollo,
    httpLink: HttpLink
  ) {
    apollo.create({
      link: httpLink.create({ withCredentials: false,
        uri: 'http://localhost:8080/graphql'}),
      cache: new InMemoryCache()
    });
  }
}

然而，在我的调试控制台中，我得到了以下错误。思想？在下面滚动查看我的javascript库的版本控制

Error: Network error: req.headers.forEach is not a function
    at new ApolloError (ApolloError.js:34)
    at QueryManager.js:277
    at QueryManager.js:655
    at Array.forEach (<anonymous>)
    at QueryManager.js:654
    at Map.forEach (<anonymous>)
    at QueryManager.webpackJsonp.../../../../apollo-client/core/QueryManager.js.QueryManager.broadcastQueries (QueryManager.js:649)
    at QueryManager.js:226
    at ZoneDelegate.webpackJsonp.../../../../zone.js/dist/zone.js.ZoneDelegate.invoke (zone.js:392)

---

我也有同样的问题。对我来说，解决这个问题的方法是交换要插入中间件的头，然后将中间件作为concat（）结果传递给link

const authMiddleware=new ApolloLink（（操作，转发）=>{
//将授权添加到标题中
操作.setContext({
headers:new HttpHeaders（）.set（'Authorization'，yourToken）
});
返回向前（操作）；
});
... 
阿波罗创造({
链接：concat（auth中间件，http），
缓存：新的InMemoryCache（）
});  

当然，您可能可以交换内容类型和任何其他您想要的头的授权

{
  "name": "frontend",
  "version": "0.0.0",
  "license": "MIT",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "^4.0.0",
    "@angular/common": "^4.0.0",
    "@angular/compiler": "^4.0.0",
    "@angular/core": "^4.0.0",
    "@angular/forms": "^4.0.0",
    "@angular/http": "^4.0.0",
    "@angular/platform-browser": "^4.0.0",
    "@angular/platform-browser-dynamic": "^4.0.0",
    "@angular/router": "^4.0.0",
    "apollo-angular": "^1.0.0",
    "apollo-angular-link-http": "^1.0.1",
    "apollo-cache-inmemory": "^1.1.1",
    "apollo-client": "^2.0.3",
    "core-js": "^2.4.1",
    "graphql": "^0.11.7",
    "graphql-tag": "^2.5.0",
    "rxjs": "^5.4.1",
    "zone.js": "^0.8.14"
  },
  "devDependencies": {
    "@angular/cli": "1.2.3",
    "@angular/compiler-cli": "^4.0.0",
    "@angular/language-service": "^4.0.0",
    "@types/jasmine": "~2.5.53",
    "@types/jasminewd2": "~2.0.2",
    "@types/node": "~6.0.60",
    "codelyzer": "~3.0.1",
    "jasmine-core": "~2.6.2",
    "jasmine-spec-reporter": "~4.1.0",
    "karma": "~1.7.0",
    "karma-chrome-launcher": "~2.1.1",
    "karma-cli": "~1.0.1",
    "karma-coverage-istanbul-reporter": "^1.2.1",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.1.2",
    "ts-node": "~3.0.4",
    "tslint": "~5.3.2",
    "typescript": "~2.3.3"
  }
}

const authMiddleware = new ApolloLink((operation, forward) => {
    // add the authorization to the headers
    operation.setContext({
        headers: new HttpHeaders().set('Authorization', yourToken)
    });

    return forward(operation);
});

... <other code>

apollo.create({
    link: concat(authMiddleware, http),
    cache: new InMemoryCache()
});