从主进程创建不可见窗口以计算Electron中的函数

Question

I am trying to write an Electron program in which the main process creates an invisible window, sends a number to that window, the window computes the factorial and then sends it back. 我正在尝试编写一个Electron程序，在该程序中主进程创建一个不可见的窗口，向该窗口发送一个数字，该窗口计算阶乘然后将其发送回去。

This is in the main process: 这是主要过程：

function invisibleWindow() {
  const invisPath = 'file://' + path.join(__dirname, 'files/html/inv.html')

  let win = new BrowserWindow({ width: 400, height: 400, show: false })
  win.loadURL(invisPath)

  win.webContents.on('did-finish-load', function () {
    const input = 100;
    win.webContents.send('compute-factorial', input);
  })



  ipcMain.on('factorial-computed', function (event, input, output) {
    const message = `The factorial of ${input} is ${output}`
    console.log(message);
  })
}

The function gets called in the main process by: 该函数在主过程中通过以下方式调用：

app.on('ready', () => {
  // creates different window here

  invisibleWindow();
});

This is the inv.html file: 这是inv.html文件：

<html>
  <script type="text/javascript">
    const ipc = require('electron').ipcRenderer
    const BrowserWindow = require('electron').remote.BrowserWindow

    ipc.on('compute-factorial', function (event, number) {
      const result = factorial(number)

      ipcRenderer.send('factorial-computed', number, result)
      window.close()
    })

    function factorial (num) {
      if (num === 0) return 1
      return num * factorial(num - 1)
    }
  </script>
</html>

Now after I have added this to my program, every time when I start it through the terminal, it does not terminate by itself even when all other (visible) windows are closed. 现在，将其添加到程序中后，每次通过终端启动它时，即使关闭了所有其他（可见）窗口，它也不会自行终止。 I guess this is because the invisible window is still opened because it did not receive the compute-factorial event. 我猜这是因为看不见的窗口仍处于打开状态，因为它没有收到compute-factorial事件。

What am I doing wrong? 我究竟做错了什么？

Answer 1

This is because of an race condition . 这是因为race condition 。 Electron docs: 电子文档：

Event: 'did-finish-load' 事件： “ did-finish-load”

Emitted when the navigation is done, ie the spinner of the tab has stopped spinning, and the onload event was dispatched. 导航完成时发出，即选项卡的微调器停止旋转，并调度onload事件。

You can try it with setTimeout : 您可以使用setTimeout尝试一下：

win.webContents.on('did-finish-load', function () {
  setTimeout(() => {
    const input = 100;
    win.webContents.send('compute-factorial', input);
  }, 3000);
});

The main process does not know when the DOM is ready. 主进程不知道DOM准备就绪的时间。 You can do something like this. 你可以做这样的事情。

Send your main process an "dom-is-ready" event. 向您的主要流程发送“准备就绪”事件。

inv.html inv.html

ipc.send('dom-is-ready');

Paste your 'did-finish-load' code into 'dom-is-ready' . 将您的“完成加载”代码粘贴到“ dom-is-ready”中 。

main.js main.js

function invisibleWindow() {
  const invisPath = 'file://' + path.join(__dirname, 'files/html/inv.html');

  const win = new BrowserWindow({ 
    width: 400, 
    height: 400, 
    show: false 
  });

  win.loadURL(invisPath);

  win.webContents.on('did-finish-load', function () {
    win.show();
  });

  ipcMain.on('dom-is-ready', function (event) {
    const input = 100;
    win.webContents.send('compute-factorial', input);
  });

  ipcMain.on('factorial-computed', function (event, input, output) {
    const message = `The factorial of ${input} is ${output}`
    console.log(message);
  });
}

从主进程创建不可见窗口以计算Electron中的函数

问题描述

1 个解决方案

解决方案1
3 已采纳 2017-09-11 07:38:04

从主进程创建不可见窗口以计算Electron中的函数

问题描述

1 个解决方案

解决方案1 3 已采纳 2017-09-11 07:38:04

解决方案1
3 已采纳 2017-09-11 07:38:04