【发布时间】：2022-06-17 19:58:48
【问题描述】：
我正在尝试为身体定位数据创建一个调试应用程序。此数据通过我的receiveAndConversion.js 中的 MQTT 作为 JSON 接收。我能够正确接收数据并打印到控制台。到目前为止，一切都很好。但现在我希望在我的主窗口中显示我收到的值（例如当手合上时使屏幕变为绿色）。
我尝试了很多东西，包括 ipc 和添加
nodeIntegration: true, contextIsolation: false, enableRemoteModule: true, 作为main.js 中的首选项
研究这个有点痛苦，因为我总是遇到有人试图从main.js而不是渲染器更改DOM的问题。
我是电子新手，并且一直在文档上花费数小时，但他们的所有示例都是在启动应用程序时触发或通过按钮（用户交互）触发的。我需要在收到新消息时更改 DOM，这与用户交互或其他事情无关。
我现在的结构是这样的：
- main.js
- receiveAndConversion.js
- index.html
- renderer.js
除了receiveAndConversion.js、renderer.js和main.js中提到的Preferences之外，代码与The quick start guide大致相同。
似乎阻止我的主要问题是，我似乎无法从我收到新消息时运行的 receiveAndConversion.js mqttClient.on() 调用我的 renderer.js。我的想法是我可以从那里调用 render.js 中的渲染函数，但是从 receiveAndConversion.js 调用它时，我收到“未定义文档”错误（至少我相信这是原因）。
如果您对我如何实现这一点而无需将所有内容都放入 main.js 有一个想法，我将不胜感激。
您可以在下面找到完整的代码。
// main.js
// Modules to control application life and create native browser window
const { app, BrowserWindow, ipcMain } = require('electron')
//const Renderer = require('electron/renderer')
const path = require('path')
const mqttClient = require('./receiveAndConversion.js')
const createWindow = () => {
// Create the browser window.
const mainWindow = new BrowserWindow({
width: 800,
height: 600,
webPreferences: {
//nativeWindowOpen: true,
nodeIntegration: true,
contextIsolation: false,
enableRemoteModule: true,
preload: path.join(__dirname, 'preload.js')
}
})
// and load the index.html of the app.
mainWindow.loadFile('index.html')
// Open the DevTools.
// mainWindow.webContents.openDevTools()
}
// This method will be called when Electron has finished
// initialization and is ready to create browser windows.
// Some APIs can only be used after this event occurs.
app.whenReady().then(() => {
//
//ipcMain.handle('left-hand-closed', (event, arg) => {
// console.log('left hand is closed');
//}
//)
createWindow()
app.on('activate', () => {
// On macOS it's common to re-create a window in the app when the
// dock icon is clicked and there are no other windows open.
if (BrowserWindow.getAllWindows().length === 0) createWindow()
})
})
// Quit when all windows are closed, except on macOS. There, it's common
// for applications and their menu bar to stay active until the user quits
// explicitly with Cmd + Q.
app.on('window-all-closed', () => {
if (process.platform !== 'darwin') app.quit()
})
// In this file you can include the rest of your app's specific main process
// code. You can also put them in separate files and require them here.
<!--index.html-->
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<!-- https://developer.mozilla.org/en-US/docs/Web/HTTP/CSP -->
<meta http-equiv="Content-Security-Policy" content="default-src 'self'; script-src 'self'">
<meta http-equiv="X-Content-Security-Policy" content="default-src 'self'; script-src 'self'">
<title>Hello World!</title>
</head>
<body>
<h1>Hello World!</h1>
We are using Node.js <span id="node-version"></span>,
Chromium <span id="chrome-version"></span>,
and Electron <span id="electron-version"></span>.
<!-- Create different field which will be used to visualise if hands are open or not. So one field for left hand one field for right hand. -->
<div id="left-hand"></div>
<div id="right-hand"></div>
<!-- You can also require other files to run in this process -->
<script src="./renderer.js"></script>
</body>
</html>
//renderer.js
// get info of open or closed hands from receiveAndConversion.js
// then make the left-hand div or right-hand div green or red depending on open or closed
//const {ipcRenderer} = require('electron')
// //write something in the divs
// leftHandDiv.innerHTML = 'Left Hand: ' + leftHandClosed
// rightHandDiv.innerHTML = 'Right Hand: ' + rightHandClosed
// ipcRenderer.handle('left-hand-closed', (event, arg) => {
// leftHandDiv.innerHTML = 'Left Hand: ' + arg
// }
// )
// ipcRenderer.handle('right-hand-closed', (event, arg) => {
// rightHandDiv.innerHTML = 'Right Hand: ' + arg
// }
// )
function handChange(leftHandClosed, rightHandClosed) {
//get the divs from the html file
const leftHandDiv = document.getElementById('left-hand')
const rightHandDiv = document.getElementById('right-hand')
//check if the hand is open or closed
if (leftHandClosed) {
leftHandDiv.style.backgroundColor = 'green'
console.log('left hand is closed');
} else {
leftHandDiv.style.backgroundColor = 'red'
console.log('left hand is open');
}
if (rightHandClosed) {
rightHandDiv.style.backgroundColor = 'green'
console.log('right hand is closed');
} else {
rightHandDiv.style.backgroundColor = 'red'
console.log('right hand is open');
}
}
//make handChange() usable outside of the renderer.js
module.exports = {
handChange
}
// preload.js
// All of the Node.js APIs are available in the preload process.
// It has the same sandbox as a Chrome extension.
window.addEventListener('DOMContentLoaded', () => {
const replaceText = (selector, text) => {
const element = document.getElementById(selector)
if (element) element.innerText = text
}
for (const dependency of ['chrome', 'node', 'electron']) {
replaceText(`${dependency}-version`, process.versions[dependency])
}
})
【问题讨论】：
标签： javascript html electron ipc