electron加载create-react-app打包后的文件一片空白

使用create-react-app的npm run bild命令打包react。
使用electron-builder打包成exe。

package.json部分代码

"main": "public/electron.js",
  "repository": "https://github.com/electron/electron-quick-start",
  "homepage": ".",
  "author": "GitHub",
  "build": {
    "publish": [
      {
        "provider": "generic",
        "url": "http://localhost:4000/electron/"
      }
    ],
    "directories": {
      "output": "release",
      "app": "./"
    },
    "files": [
      "build/**/*"
    ],
    "win": {
      "target": [
        "nsis",
        "zip"
      ]
    },
    "nsis": {
      "oneClick": false,
      "allowToChangeInstallationDirectory": true,
      "perMachine": true
    }
  },
  "scripts": {
    "dev": "concurrently \"set BROWSER=none&&react-scripts start\" \"wait-on http://localhost:3000 && electron .\"",
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject",
    "dist": "electron-builder"
  },

public/electron.js加载create-react-app打包后的代码

 if (isDev) {
        mainWindow.loadURL("http://localhost:3000/");
    } else {
        mainWindow.loadURL(url.format({
            pathname: path.join(__dirname, './../build/index.html'), // 修改
            protocol: 'file:',
            slashes: true
        }))
    }

npm run dist打包成功，打开exe安装后显示一片空白，控制台没有显示出错。