用代理发布请求不起作用angular7 httpclient和expressjs

Question

我几个小时都在解决这个问题

我有一个简单的带有数据服务的客户端，该客户端从epxress js服务器获取数据，并允许通过发布请求创建数据。

GET请求仅适用于代理。该帖子根本无效。

我在服务器端收到请求，但是主体为空，似乎存在一些我不理解的cors问题

客户端'proxy.conf.json'

中的代理

{
  "/": {
    "target": "http://127.0.0.1:3000",
    "secure": false,
    "logLevel": "debug"
  }
}

运行ng serve --proxy-config=proxy.conf.json

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

@Injectable({
  providedIn: 'root'
})
export class DataService {  
  constructor(private httpclient:HttpClient) { }

  async get_dogs(){
    return await this.httpclient.get<Dog[]>('/dogs').toPromise();
  }

  async create_dog(dog){
    return await this.httpclient.post<Dog>('/dogs',dog).toPromise();
  }
}

表达.js

const express = require('express');
const bodyParser = require('body-parser');
const {initElements, createElement } = require('./utils');


const app = express();

const port = 3000;
const dogsRouter = express.Router();

app.use(bodyParser.text());

app.listen(port, () => console.log(`Example app listening on port ${port}!`));
app.get('/', (req, res) => res.send('Hello World!'));


const dogs = [];
initElements(dogs);


app.use('/dogs', dogsRouter);

// Get all dogs
dogsRouter.get('/', (req, res, next) => {
  res.send(dogs);
});

// Create an expression
app.post('/dogs', (req, res, next) => {
  console.log(req);
  const newDog = createElement(req.query);
  if (newDog) {
    dogs.push(newDog);
    res.status(201).send(newDog);
  } else {
    res.status(400).send();
  }
});