Reactjs 电子版生成后express服务器不工作

我对电子技术还不熟悉，一直在生产中。我的应用程序在开发模式下运行良好，但在我构建应用程序并运行桌面应用程序后，它一直无法满足我对服务器的请求。我使用react作为前端，express作为后端，并将它们与electron捆绑在一起。现在确定package.json中的代理是否导致了问题。谁能帮帮我吗

我的文件夹结构如下所示

• 计划
  • 前端 -建造 -公开的 -electron.js -Src
  • 后端 -server.js

mypackage.json

{
  "name": "Myapp",
  "version": "0.1.0",
  "description": "My first electron app",
  "author": "HenryLee",
  "main": "public/electron.js",
  "proxy": "http://localhost:5000",
  "build": {
    "appId": "com.myapp.firstelectronapp",
    "icon": "build/icon.ico"
  },
  "homepage": "./",
  "dependencies": {
    "@testing-library/jest-dom": "^4.2.4",
    "@testing-library/react": "^9.5.0",
    "@testing-library/user-event": "^7.2.1",
    "axios": "^0.20.0",
    "cross-env": "^7.0.2",
    "electron-is-dev": "^1.2.0",
    "react": "^16.14.0",
    "react-dom": "^16.14.0",
    "react-scripts": "3.4.3",
    "smalltalk": "^4.0.7"
  },
"scripts": {
    "react-start": "react-scripts start",
    "react-build": "react-scripts build",
    "react-test": "react-scripts test",
    "react-eject": "react-scripts eject",
    "electron-build": "electron-builder",
    "build": "npm run react-build && npm run electron-build",
    "start": "concurrently \"cross-env BROWSER=none npm run react-start\" \"wait-on http://localhost:3000 && electron .\""
  },
"devDependencies": {
    "concurrently": "^5.3.0",
    "electron": "^10.1.3",
    "electron-builder": "^22.9.1",
    "wait-on": "^5.2.0"
  }

我的electron.js

const { app, BrowserWindow, Menu, shell } = require('electron')
const isDev = require('electron-is-dev')
const path = require('path')
const isMac = process.platform === 'darwin'

function createWindow () {
  const win = new BrowserWindow({
    width: 1300,
    height: 665,
    icon: path.join(__dirname, 'ctklogo.png'),
    webPreferences: {
      nodeIntegration: true
    }
  })

  win.loadURL(
    isDev ? 'http://localhost:3000' : `file://${path.join(__dirname, "../build/index.html")}`
  )
}
app.on('window-all-closed', () => {
  if (process.platform !== 'darwin') {
    app.quit()
  }
})

app.on('activate', () => {
  if (BrowserWindow.getAllWindows().length === 0) {
    createWindow()
  }
})

My server.js（Express server）

const express = require('express');
const app = express();
const request = require('request');
const cors = require('cors');
const PORT = 5000;
const bodyParser = require('body-parser');
const path = require('path');

// middleware
app.use(express.json())
app.use(express.static(path.join(__dirname, '../frontend/build')))
app.use(bodyParser.urlencoded({ extended: true}))
app.use(cors())
app.use(bodyParser.json())