Electron: Call renderer function from main

2019-04-28 06:45发布

问题:

I have some data in the localstorage that has to be deleted on app.quit(). But I see no way to do so from the main process.

Is there a way to call a renderer function from main?

I know about var remote = require('remote'); but it seems to go only in the wrong direction.

回答1:

You can send messages from the main process to a renderer process via webContents.send as called out in the documentation here: https://github.com/atom/electron/blob/master/docs/api/web-contents.md#webcontentssendchannel-arg1-arg2-.

Here is how you do it straight from the docs:

In the main process:

// In the main process.
var window = null;
app.on('ready', function() {
  window = new BrowserWindow({width: 800, height: 600});
  window.loadURL('file://' + __dirname + '/index.html');
  window.webContents.on('did-finish-load', function() {
    window.webContents.send('ping', 'whoooooooh!');
  });
});

In index.html:

<!-- index.html -->
<html>
<body>
  <script>
    require('electron').ipcRenderer.on('ping', function(event, message) {
      console.log(message);  // Prints "whoooooooh!"
    });
  </script>
</body>
</html>

Note it is asynchronous. I am not sure how that affects things with your particular solution, but this should at least get you talking back to the renderer process.



回答2:

You might use BrowserWindow.webContents.executeJavaScript like so in your main process:

// will print "whoooooooh!" in the dev console
window.webContents.executeJavaScript('console.log("whoooooooh!")');

Although you might consider it a kinda messy/dirty approach, it works. And it does not require setting up anything in the renderer process which greatly simplified things for me.
If you just want to call a particular method it would probably be quicker to write this way.