HTTP 请求元素在 Node js 中始终未定义

Question

我有这样的问题。我正在制作一个平均堆栈应用程序。在该文件中，我创建了一个服务文件来处理预订。它看起来像这样。

import { Injectable } from '@angular/core';
import { HttpClient , HttpHeaders } from '@angular/common/http';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/toPromise';
import {Reservation} from "./reservation";
@Injectable()
export class ReservationService {
public selectedReservation: Reservation = new Reservation();
public  reservations: Reservation[];
constructor(private http: HttpClient) { }
getNotConfirmedReservationList(){
return this.http.get('http://localhost:3000/reservation/notComfirmed')
}
confirm(_id: string){
console.log(_id);
let headers = new HttpHeaders();
headers.append('Content-Type', 'application/json');
return this.http.post('http://localhost:3000/reservation/confirm', _id, {headers: headers});
}
}

在这里，我放了一个控制台日志，它正确打印了id。但是在用 Express 制作的 API 的控制器文件中，我再次控制台记录它给我的 Id 作为未定义的输出。在这里，我在 API 中提供我的控制器文件。

const express = require('express');
var router = express.Router();
var  Reservation  = require('../models/reservation');
router.post("/create",function (req,res) {
const newReservation = new Reservation({
date: req.body.date,
from: req.body.from,
to: req.body.to,
lab: req.body.lab,
name: req.body.name,
email: req.body.email,
role: req.body.role,
year: req.body.year,
reason: req.body.reason,
state: "Not Comfirm"
});
Reservation.saveReservation(newReservation, function (err, reservation) {
if (reservation) {
res.send(reservation);
}
else {
console.log('Error in User save :' + JSON.stringify(err, undefined, 2));
}
});
});
router.get('/notComfirmed', function (req, res) {
Reservation.findNotComfirmed(function (err, reservations) {
if(err) throw err;
if (!reservations){
res.json({state:false,msg:"No reservations found"});
}
if(reservations){
res.json(reservations);
}
})
});
router.post('/confirm', function(req, res){
const _id= req.body._id;
console.log(req.body._id);
Reservation.updateReservation(_id, function (err, reservation) {
if(err) throw err;
if (!reservation){
res.json({state:false,msg:"Something went wrong"});
}
if(reservation){
res.json(reservation);
}
})
})

module.exports = router;

我尝试了很多次来找到我的代码的问题。但我找不到它。有人可以帮助我找到此代码的问题吗？谢谢！

Answer 1

1. 您没有正确设置请求正文。将return this.http.post('http://localhost:3000/reservation/confirm', _id, {headers: headers});替换为return this.http.post('http://localhost:3000/reservation/confirm', {_id}, {headers: headers});

2. 您没有分析请求正文。将router.post('/confirm', function(req, res)替换为router.post('/confirm', json(), function(req, res)并导入const json = require('body-parser').json。最终你必须npm i --save body-parser.