Question

我无法使用mongoose从mongoDB（MEAN应用程序）中检索项目列表。我想检索数据库中存在的每个对象（及其属性），然后将结果保存到对象的本地数组中。

我的后端工作正常，使用邮递员或本地主机，我可以看到检索到的数据作为JSON对象。但是我似乎无法将其保存到数组中。

后端部分：App.js：

const express = require('express');
const bodyParser = require('body-parser');
const mongoose = require('mongoose');
const app = express();
let ObjectId = require('mongoose').Types.ObjectId;
const Player = require('./Model/player');


app.use((req, res, next) => {
    res.setHeader('Access-Control-Allow-Origin', "*");
    res.setHeader('Access-Control-Allow-Headers', "Origin, X-Requested-Width, Content-Type, Accept")
    res.setHeader('Access-Control-Allow-Methods', "GET, POST, PATCH, PUT, OPTIONS");
    next();
});


app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));

app.get('/api/players', (req, res, next) => {   
    Player.find((err, docs) => {
        if (!err) {
            console.log(docs)
            res.send(docs)}
        else { console.log("Error : " + JSON.stringify(err, undefined, 2)) }
    });
});

前端：我的播放器型号：

export interface IPlayer {
_id:string,
username: string;
rank: number;
score: number;
status:string;
time: string;
fGame: string;
}

players-service（从数据库中检索结果：

import { IPlayer } from './player.model';
import { Injectable } from '@angular/core';
import { Subject, Observable } from 'rxjs';
import { HttpClient } from "@angular/common/http";



@Injectable({ providedIn: 'root' })
export class PlayersService {
    public playersArr: IPlayer[]=[];
    private playersUpdated = new Subject<IPlayer[]>();

    selectedPlayer: IPlayer;

    constructor(private http: HttpClient) {

    }
    getPlayers():Observable<IPlayer[]> {

        const result =  this.http.get<IPlayer[]>('http://localhost:3000/api/players');
        console.log(result);
        return result;
    };

最后，播放器列表组件：

import { Component, OnInit, OnDestroy } from '@angular/core';
import { IPlayer } from '../player.model';
import{ PlayersService } from '../players.service';
import { Subscription  } from 'rxjs';

@Component({
  selector: 'app-player-list',
  templateUrl: './player-list.component.html',
  styleUrls: ['./player-list.component.css']
})
export class PlayerListComponent implements OnInit{

  players : IPlayer[] = [];
  private postsSub: Subscription;

  constructor(public playS : PlayersService) { }

  ngOnInit() {
    this.playS.getPlayers()
      .subscribe(data =>
        this.players=data);
  }
}

所以我的问题是在这里，数组“玩家”保持为空。我尝试过分配它，然后再将其发送到列表组件，仍然一无所获有任何想法吗？

猫鼬-Angular8的Get方法不保存值

0 个答案: